What’s the risk if Australia opens its international borders? An epidemiologist explains


Tony Blakely, The University of MelbourneCoinciding with the Trans-Tasman travel bubble starting today, over the past week there have been murmurings Australia could soon relax its borders further, through mechanisms such as home quarantine or letting in vaccinated people.

But what are the risks?

Here I propose three things we must consider:

  • the prevalence of the virus in the country from where travellers are coming, including the strain of virus
  • measures taken for the people travelling, including home quarantine and whether travellers are vaccinated
  • the percentage of our population who are immune.

Importantly, all these factors matter. It’s not simply a case of needing to ensure all travellers are vaccinated.

The level of infection in the country of origin matters enormously

At around Christmas time, roughly 2% of the UK population was infected. That percentage is now considerably less, but it’s still likely around 1,000 times higher or more than the risk in China and other East Asian countries. The risk is near zero for New Zealand, Taiwan and many Pacific countries.

However, things will change. At the moment the United States seems to be maintaining high infection rates while also rapidly vaccinating the population. This is probably because of more transmissible variants, and society loosening up, offsetting gains from more people being immune. But at some point, perhaps around mid-year, the infection rate in the US should plummet as the percentage of people immune increases to somewhere around 60-80%. All this is to say we can expect infection rates in countries to vary a lot in the next six to 12 months.




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Let’s work through an example of the United Kingdom. Assume the UK has another surge of infections such that 0.5% of British people are infected and unaware of it, and could jump on a plane to Australia. Let’s assume we decide to let 10,000 Brits come to Australia each month. So 0.5% of 10,000 would mean roughly 50 infected people arriving per month.

Mitigating the risk of travellers

Of course, we would do more to reduce the risk. We could test people before they get on the plane and when they arrive. Let’s assume that weeds out another 50%, as the other half may be still incubating and not yet testing positive. That’s 25 COVID-positive British people arriving per month.

Next, let’s assume we require all travellers to be vaccinated. That will reduce their risk of unwittingly carrying the virus (through either symptomatic or asymptomatic infection) by between 66% for the UK variant and 81% for “normal” virus for the AstraZeneca vaccine. Data are still sketchy on any infection for Pfizer, but it’s likely 90% or more, given 95% protection against symptomatic disease in Pfizer’s clinical trial. If we assume 80%, we are now down to five infected Brits arriving here per month.

Importantly, the vaccine also reduces both the duration of the disease and its infectiousness, for vaccinated people unlucky enough to get infected. We don’t know by how much as the real-world evidence is still accruing, although animal data on peak viral load and duration of likely infective viral load supports this contention.

If we assume (conservatively in my view) that there is a 50% reduction in duration and 50% reduction in peak infectivity for hapless vaccinated people who still get infected, that is 25% of the risk of passing it on (that is, 50% of 50%).

Therefore, if an unvaccinated person, infected with the UK variant, was going to infect an average of 3.5 people in the absence of any social measures such as mask-wearing, the infected-after-vaccination person would only infect 0.875 other people – a 75% reduction in the reproductive rate. So our remaining five infected Brits are less infectious.

Intensity of quarantine measures for arrivals

Let’s consider the option of home quarantine. We don’t know how effective this will be, because of potential compliance issues.

But the risk of home quarantine breaches can be reduced by technology like ankle bracelets, GPS tracking on travellers’ phones to ensure they stay home, and only allowing home quarantine if any other members of the household are also vaccinated, to give an extra layer of protection.

Let’s assume home quarantine with these extra measures stops 80% of infected people getting out and about in Australia while infectious.

So we are now down to one infected British person who has slipped through per month. But given they are also vaccinated, they’re less likely to pass on the infection. And this risk can be reduced further still by ensuring they’re wearing a mask – although if they “breached” home quarantine rules they may not be likely to wear a mask.

It’s important to remember even “proper” quarantine isn’t foolproof. About one in 250 infected people last year in hotel quarantine caused a leakage.

Is Australia a tinderbox?

Yes. Perhaps only 5% of us are immune. Even if, via the above measures, we get just one infected person a month in Australia – the situation could blow up. Keep in mind the above example assumes we’re only allowing travellers from one country too. More countries means more travellers means more risk – although as above, the risk varies based on the infection rate in the origin country.

You can play with various scenarios in our COVID-19 Pandemic Trade-offs tool, launched two weeks ago. What you’ll find is that until most adults in Australia are vaccinated, any loosening up of how we respond to the virus incursion is unwise. If contact tracing cannot mop up the inevitable incursions, we’ll still need to use social restrictions, including lockdowns, until the vaccination rollout is complete.

But we can probably think about inching forward to some increased risk once all over-50s are vaccinated (phase 2A), with some modest relaxation of the border. Yet we can never totally escape the risk of outbreaks.

So what can we do now with borders?

First, continue with the Trans-Tasman bubble.




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Second, remove or greatly reduce quarantine for vaccinated travellers from many East Asian countries, which present a low risk to Australia. As an example, the average number of known active infectious people in China at any point in time recently is about 250. Let’s assume this equates to about 100 unknown infections at any point in time (that is, people who are not yet symptomatic or detected). For a population of 1.4 billion, that’s a 0.000007% risk of any person in China being infected.

This suggests that for 10,000 vaccinated arrivals from China per month with modified quarantine, the expected number of infected people unwittingly getting out into the Australian population per month is 0.000014. Or, put another way, our above UK example presents 70,000 times the risk of an arrival from China. Given such low risk, it’s hard to justify why university students from China cannot start in time for semester two this year if they’re vaccinated and going into some form of modified quarantine.

Third, we need a national framework to assess the risk. Focusing on one measure alone isn’t wise — you have to look at the whole system. Such a framework can be developed now, at the same time as setting our risk thresholds so policy-makers, airlines and other industries can start planning.The Conversation

Tony Blakely, Professor of Epidemiology, Population Interventions Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Doctors do not face a greater legal risk if they give AstraZeneca to younger Australians — here’s why


Simon Santi/AAP

Cameron Stewart, University of SydneyLast week, the federal government changed its recommendation for COVID-19 vaccines. The Pfizer vaccine is now the “preferred” jab for adults under 50.

Amid the political fallout and worries about what it means for Australia’s COVID recovery, doctors have expressed concern about their liability. Some said they would even stop giving the AstraZeneca jab until they were more certain of their position.




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Are they at greater legal risk if they give AstraZeneca to younger Australians? The government insists they are not. This is correct — here’s why.

Proving fault

In Australia, medical liability is, for the most part, fault-based. This means patients who are injured by medicines, medical devices and medical interventions must prove the doctors who used them were to blame for any injury they suffered before any compensation will be paid.

Australian liability laws are state-based, but generally speaking, fault can only be proven when the doctor has acted outside of the professional standard of care in a way that is not supported widely in Australia by professional peers.

What is the standard of care?

The standard of care for diagnosis and treatment is effectively set by the medical profession. In cases — such as COVID vaccines — where the treatment is new and knowledge about the treatment is emerging, the standard of care is also developing.

Importantly, doctors are judged by measuring their behaviour against the standard of care at the time the treatment was given. This means that if, in 2020 a doctor administers a COVID vaccine in a way that was supported by their peers at that time, they will not be found to have breached the standard of care if, years later, other side effects become known.

Prime Minister Scott Morrison inspecting AstraZeneca production.
Last week the Morrison government changed its advice around the AstraZeneca vaccine.
David Caird/AAP

We should also be careful not to automatically equate the government’s advice concerning the AstraZeneca vaccine with what the standard of care should be at the individual level.

The government’s advice is concerned with the big picture and with risks across a population. Doctors have the task of treating individuals. So, the government’s advice should be considered by doctors when working out which vaccines to offer to patients, but there may well be situations where the AstraZeneca is the best option for individual adult patients under 50.

Giving advice and accepting risks

Doctors also have a duty to inform individual patients about material risks of the treatments they provide. Every intervention comes with a set of risks but only the material ones need to be disclosed.

Material risks include those the profession would usually notify patients of (objective material risks), as well as risks the individual patient may have a particular concern about (subjective material risks).

The classic example of this is the 1993 case of Rogers v Whitaker where a woman who was blind in one eye was considering cosmetic surgery on that eye. She was concerned about any risk (no matter how remote) of going blind in her “good eye”. Later, she became blind from a complication of her treatment, which was known but very rare. The doctor’s failure to inform her was considered a breach of the duty to inform — even though it was not a risk normally disclosed — because the risk was subjectively material to her.

Again, the doctor will always be judged by what the profession knew at the time regarding these risks. If a patient is told about the material risks of the treatment and decides to go ahead with the treatment, the doctor has satisfied their legal duty to advise and cannot be held liable for subsequent injuries.

What now for GPs and AstraZeneca?

As long as doctors consider the government advice, keep up with professional news about best practice and communicate material risks to patients, they face no greater liability for providing COVID vaccines than they do for any other treatment.

The reality is the risks of people being injured by vaccines, and of doctors being sued for vaccine-related injury, is incredibly low.

At the weekend, the Australian Medical Association also said if a patient makes an informed decision to receive the AstraZeneca vaccine, GPs are protected under professional indemnity insurance.

Of course, the reality of low risk may not match the fear practitioners experience. So, are there things we can do to reduce the anxiety practitioners feel regarding liability?




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One obvious measure is to move to no-fault systems of compensation. Many countries including the United States and New Zealand have no-fault compensation schemes for vaccine-related injury. Putting such a scheme in place may very well help doctors get over the fear of being sued. It might also give patients confidence knowing that in an extremely rare case of injury, they will be covered.

This could be done either with a one-off scheme or by expanding the National Injury Insurance Scheme, which covers personal injuries from motor vehicle accidents.

Without such schemes, Australian patients will only have access to compensation for vaccine-related injury if they can prove it was caused by a failure to act according to medical standards of care or a failure to properly inform the patient of material risks.The Conversation

Cameron Stewart, Professor at Sydney Law School, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The best hope for fairly distributing COVID-19 vaccines globally is at risk of failing. Here’s how to save it


Deborah Gleeson, La Trobe UniversityCOVAX, the global initiative to coordinate the distribution of COVID-19 vaccines in an equitable way, is crucial for bringing the pandemic under control.

But COVAX’s aim of delivering 2 billion doses to participating countries by the end of 2021 — including 92 low-income countries that can’t afford to buy vaccines directly from manufacturers — is threatened by chronic under-investment, vaccine nationalism and export restrictions.

COVAX is not intended only for low-income countries: Canada has so far received 316,800 doses through the scheme. As such, it represents an important “insurance policy” for Australia, potentially enabling access to a wider portfolio of vaccines than we could secure through negotiations with suppliers.

The vulnerability of our vaccine procurement strategy has become clearer over the last few weeks, with supply blockages limiting vaccine imports from Europe and now the government’s warning about the AstraZeneca vaccine and its links to a rare blood-clotting disorder.

Saving COVAX will require more than donations (of both funds and vaccines), as well as the removal of export bans. Countries must collaborate to urgently remove the legal and technical barriers preventing more widespread vaccine manufacturing in order to increase the global supply of vaccines for COVAX to distribute.




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How does COVAX work?

COVAX is led by the Coalition for Epidemic Preparedness Innovations (CEPI); Gavi, the Vaccine Alliance (a public-private partnership that aims to increase vaccination in low-income countries); and the World Health Organization.

It aims to deliver doses to all of the participating countries that have requested them in the first half of 2021, and 2 billion vaccines in total by the end of 2021.

COVAX is complex, but essentially it works by investing in a portfolio of promising vaccines and then distributing them according to a formula to both “self-financing countries” and “funded countries”.

Self-financing countries are those which have contributed funds to COVAX, such as Australia. They are able to buy the vaccines at cheaper prices negotiated by COVAX and will initially receive enough to vaccinate 20% of their populations. In the longer term, these countries may receive enough doses to vaccinate up to half of their populations, depending on how much they contribute.

Funded countries include 92 low-income countries that can’t afford to buy their own vaccines. They will also receive enough to vaccinate 20% of their populations, provided COVAX is able to meet its goals. This is nowhere near enough to achieve herd immunity, but will at least allow health workers and the most vulnerable groups to be vaccinated.

Australia has committed A$123.2 million to enable it to purchase 25 million vaccines for domestic use.

It has also committed A$80 million specifically earmarked for providing vaccines for low-income countries. This money will be drawn from existing aid funding, however, and won’t go very far in terms of assistance.

How is the program going so far?

COVAX made its first delivery of vaccines to Ghana on February 24. By April 11, it had shipped approximately 38.5 million doses to 106 countries and territories.

The first shipment of COVID-19 vaccines distributed by COVAX arriving in Ghana.
Francis Kokoroko/UNICEF/AP

While these figures might look promising at first glance, this is a long way behind COVAX’s aim to deliver 100 million doses by the end of March.

And they don’t stand up well in the context of global vaccine roll-outs. So far, only 0.2% of the 700 million vaccine doses administered globally have been given in low-income countries, whereas 87% have been received by people in high-income and upper middle-income countries.

Tedros Adhanom Ghebreyesus, director-general of the WHO, pointed out last week that only one in 500 people in low-income countries have so far received a vaccine — a situation he described as a “shocking imbalance”.




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Why is COVAX struggling to deliver?

COVAX needs more funding, to the tune of US$3.2 billion even to meet its modest goals for 2021. But the supply of vaccines is an even bigger problem.

Rich countries like Australia have undermined COVAX by negotiating deals for vaccines directly with pharmaceutical companies, rather than waiting for COVAX to allocate them fairly. By last November, high-income countries making up just 14% of the world’s population had negotiated pre-market agreements covering 51% of the global supply.

Adding to COVAX’s problems, the flow of vaccine deliveries has mostly dried up in the last week.

Some 90 million doses of the AstraZeneca vaccine manufactured in India that were to be delivered to 64 countries in March and April have been delayed as a surge in COVID-19 cases prompted the Indian government to restrict exports.

Boxes of AstraZeneca COVID-19 vaccines manufactured by the Serum Institute of India and provided through the COVAX global initiative arrive at the airport in Mogadishu, Somalia.
Farah Abdi Warsameh/AP

What needs to happen?

WHO has called on rich countries to immediately share 10 million doses to prop up COVAX in the first half of 2021.

But so far, no country has committed to do this. Donations that come after countries have fully vaccinated their own populations will be too late. And where bilateral donations have been made outside of the COVAX program (mainly by China and Russia), they have largely been driven by security, strategic or political considerations, rather than donated to the countries where they are most needed.




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Removing export restrictions would help. But as long as demand exceeds supply and the countries where vaccines are manufactured face large outbreaks, we are likely to continue to see these types of barriers.

What is needed most are more sustainable approaches to dramatically boost the global supply of vaccines and ensure there’s enough to go around.

This first requires removing the intellectual property protections that allow vaccine developers to hold exclusive rights to control who can make and sell them.

India and South Africa have put forth a proposal at the World Trade Organization to waive intellectual property rights for COVID-19 medical products during the pandemic, which has been supported by more than 100 low- and middle-income countries. However, several high-income countries, including Australia, have blocked it.

Secondly, governments need to support mechanisms for sharing intellectual property, such as the WHO’s COVID-19 Technology Access Pool (C-TAP).

This was set up nearly a year ago, but no vaccine developer has contributed to it yet. Governments need to make sharing intellectual property and contributing to the pool a condition of public funding for the development of COVID-19 products.

Finally, governments need to help low- and middle-income countries to produce their own vaccines. This means investing money to build up manufacturing capacities in these countries and facilitating technology transfers from companies based in high-income countries.

For COVAX to supply enough vaccines for even 20% of the world’s population, rich countries will need to step up. And fast.The Conversation

Deborah Gleeson, Associate Professor in Public Health, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

AstraZeneca’s blood clot risk is incredibly small. Australia shouldn’t follow the UK’s lead of offering under 30s another vaccine


Nathan Bartlett, University of NewcastleAuthorities in the United Kingdom overnight recommended people under 30 be offered an alternative COVID vaccine to the AstraZeneca/Oxford shot.

The recommendation came after the European Medicines Agency (EMA) found a “possible link” between the vaccine and blood clots. The EMA also said blood clots should be listed as a “very rare” side effect of the vaccine.

It’s important to note there’s still no conclusive evidence the vaccine is causing the clots, as so few have been reported. However, evidence there is a link is increasing, which has prompted more focused monitoring.

The benefits of getting a COVID vaccine still far outweigh the risks. I would still be encouraging everyone to be vaccinated with the AstraZeneca vaccine.

Prime Minister Scott Morrison said this morning “there’s nothing to suggest at this stage that there would be any change” to Australia’s current rollout strategy. The Therapeutic Goods Administration and the Australian Technical Advisory Group on Immunisation are currently reviewing the data and latest advice from Europe and the UK.

What’s causing these clots?

Blood clotting events linked to vaccination are being called “vaccine-induced prothrombotic immune thrombocytopenia” (VIPIT).

In these rare instances, clots are forming in a patient’s blood, and not just in veins but in arteries and other rare locations like the brain and abdomen. This is also paired with low platelet counts (cells needed for the blood to clot).




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It appears, in these instances, the body’s response to the vaccine is triggering an “off target” immune response that is attacking platelets. Limited data that is yet to be peer reviewed suggests antibodies targeting platelets cause them to become activated and trigger clotting. This autoimmune response also targets the platelets for destruction, reducing their level in the blood. So platelets are either tied up in clots or are eliminated. Both processes contribute to “thrombocytopenia” (low blood platelet count).

Like infections, vaccines trigger an immune response, so when receiving any shot that stimulates a robust immune response there’s a small but real risk your immune system will generate “off target” effects. In these rare instances, these effects can lead to autoimmunity, which is an immune response that attacks your own cells.

All vaccines and medications come with small risks

The numbers of clots reported after the AstraZeneca are very small, so we don’t exactly know how common they are. But they appear to occur at a rate between one in 25,000 and one in 500,000.

The UK’s vaccine advisory board said there were 79 cases of blood clotting issues among more than 20 million people given the AstraZeneca vaccine. That’s a chance of about 0.0004%, or one in 250,000.

Researchers haven’t yet identified any specific risk factors so far for the development of blood clots following COVID vaccination. We need to understand as quickly as possible what these are if indeed a causal link is established.

Some have suggested there could be a link with women taking the contraceptive pill having a higher risk of blood clots after receiving the AstraZeneca vaccine. But there’s no evidence for this at all. As far as I know, information on whether women receiving the vaccine are taking the contraceptive pill isn’t captured. Perhaps it’s something to consider going forward.

Young people don’t appear to be at particularly higher risk of blood clots linked to the vaccine. The publicised cases of blood clots have occurred in mostly women under 60 years of age.

Australia shouldn’t follow the UK’s new recommendation

One reason the UK is able to advise younger people to receive other vaccines is because it has other vaccine options, including the Pfizer and Moderna shots. Offering the under 30s an alternative vaccine isn’t really going to hinder the rollout, which is going very well in the UK.

But this isn’t the case in Australia. The AstraZeneca shot is the only one we have guaranteed supply of, given CSL is producing it in Melbourne.

It’s important to remember the AstraZeneca vaccine is a very safe and effective vaccine. It’s also easier to store and distribute than the Pfizer vaccine.

The priority is vaccinating as many people as possible and quickly

It’s important to note we’re in uncharted territory. This is the first time in modern history we’ve been in a situation where we’ve needed to roll out a vaccine to deal with a pandemic.

We’re also using new vaccine technologies that we’ve had to expedite to try and get on top of this virus as soon as possible. These new technologies, including AstraZeneca’s, have never been tested at this immense scale until now.

There are a lot of unknowns, but certainly the scale in which were doing this means we’re going to see very rare adverse events linked to these vaccines.

At this stage the priority is still to vaccinate as many people as possible, as quickly as possible.

My primary concern is ongoing high levels of transmission across the world. The more cases there are, and longer we delay vaccinating people, the higher the likelihood is of new variants of the virus emerging.




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Even though we have very low COVID-19 case numbers in Australia currently, we’ve seen regular outbreaks stemming from hotel quarantine. We can’t predict what’s going to happen in the future. The longer the virus is waiting at our doorstep, the greater the risk we’ll have another outbreak and end up in lockdown and much worse — and nobody wants that.The Conversation

Nathan Bartlett, Associate Professor, School of Biomedical Sciences and Pharmacy, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

5 tips for ventilation to reduce COVID risk at home and work



Shutterstock

Mary-Louise McLaws, UNSW

As many of us return to the office, and congregate indoors over dinner and drinks during the summer holidays, we need to think about ventilation to minimise the indoor spread of COVID-19.

SARS-CoV-2, the virus that causes COVID, is spread mostly by larger particles called droplets, but also by smaller particles called aerosols, and by touch from contaminated surfaces.

Aerosol particles are lighter than droplet-sized particles, and can be suspended in the air for longer. The suspension and therefore transmission of aerosols is facilitated by poor ventilation.

Increasing ventilation indoors, with fresh outdoor air, is a key method of dispersing viral particles. Ventilation can reduce the risk that just one COVID-positive person (who might not yet know they’re infectious) will infect others.

There are some simple measures you can take, both at home and at work, to improve ventilation over the holiday period and beyond.




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1. Open windows and doors

The best strategy at home and at work is simply to open windows and doors.

If you’re having friends and family over for a meal, or your office Christmas party, consider moving tables and chairs closer to open windows and open up a door to create a through breeze.

Or, if weather permits, eat outside.

2. Set your air conditioner to pull fresh air from outside

Air conditioners can help, but they must be on the right setting.

At work or home you don’t want to recirculate indoor air, as this just fans the same air around the room (but now colder or warmer).

Instead, always make sure your air conditioner is set to bring in 100% fresh air from outside. There are settings in offices that allow the system to increase air change per hour, meaning it can reduce the time it takes for all the air inside the room to be completely replaced with outside fresh air.

A person using a remote for their air conditioner
Aircons can help ventilate rooms, but only if they’re inserting fresh air from outside, rather than recirculating indoor air.
Shutterstock

But the direction of the airflow is also important. For example, airflow from an air conditioner (that was recirculating air rather than pulling it from outside) was implicated in spreading the virus to a number of diners at tables downstream in a restaurant in China.

Offices welcoming back staff should prepare their air conditioners by having their engineers service the system to pull in fresh air faster than the pre-COVID setting (which may have been around 40 litres per second per person) at no less than 60 litres per second, per person.

In hospitals, aged-care facilities and hotel quarantine, qualified engineers should be brought in to assess the adequacy of the air conditioner’s airflow. This is particularly crucial for any “hot zones” accommodating people who are COVID-positive.

The World Health Organisation recommends hot zones have 12 airflow changes per hour (that’s 80 litres per second per person), meaning the air is totally replaced 12 times every 60 minutes. This is the gold standard for ventilation, and can be very hard to achieve in many buildings.




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Many of our buildings are poorly ventilated, and that adds to COVID risks


3. Use fans

Guidelines released last week by the US Centers for Disease Control and Prevention recommend placing fans near open windows to enhance airflow. The recommendation is to keep fans on at all times when a room is occupied, for example at restaurants.

As with aircons, fans can be dangerous if they push the air directly from one person to another, and one is infectious. You should place the fan so it increases the flow of fresh air into the room, and shouldn’t be placed so the air moves from the room towards the open window or open door.

4. Don’t bother with HEPA filters at home

High-efficiency particulate air (HEPA) filters have been marketed as a way to reduce the concentration of SARS-CoV-2 particles in the air.

Their effectiveness is dependent on the airflow capacity of the unit, the configuration of the room, the number of people in the room, and the position of the filter in the room.

But there’s no evidence to suggest a portable HEPA filter unit will help in your home. So don’t rush out and buy one for Christmas.

They may be effective in some areas of health care, such as a COVID ward in a hospital or in aged care homes, particularly when used in negative-pressure rooms. The combination of the HEPA filter and negative air pressure reduces the risk of aerosol particles escaping into the corridor.

5. In public transport, taxis and Ubers

COVID outbreaks have been traced back to exposure on public transport. For example, a young man in Hunan Province, China, travelled on two buses and infected multiple people who were sitting in different areas of the buses. A study of this cluster was carried out by Chinese researchers, who put forward one theory regarding air flow:

The closed windows with running ventilation on the buses could have created an ideal environment for aerosol transmission […] the ventilation inlets were aligned above the windows on both sides, and the exhaust fan was in the front, possibly creating an airflow carrying aerosols containing the viral particles from the rear to the middle and front of the vehicle.

The study’s authors recommend all windows be open on public transport to help disperse viral particles. If you’re on a tram or a bus, you should open them if you can.

However, on some forms of public transport it might be impossible, like trains. In these instances, you should wear a mask.

Likewise, it’s ideal to have the windows down in Ubers and taxis. But if you can’t or don’t want to, turn on the air conditioner and have it pull fresh air from outside. And still wear a mask!The Conversation

Mary-Louise McLaws, Professor of Epidemiology Healthcare Infection and Infectious Diseases Control, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Many of our buildings are poorly ventilated, and that adds to COVID risks



ambimages/Shutterstock

Geoff Hanmer and Bruce Milthorpe, University of Technology Sydney

The virus that causes COVID-19 is much more likely to spread indoors rather than outdoors. Governments are right to encourage more outdoor dining and drinking, but it is important they also do everything they can to make indoor venues as safe as possible. Our recent monitoring of public buildings has shown many have poor ventilation.

Poor ventilation raises the risks of super-spreader events. The risk of catching COVID-19 indoors is 18.7 times higher than in the open air, according to the US Centers for Disease Control and Prevention.




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In the past month, we have measured air quality in a large number of public buildings. High carbon dioxide (CO₂) levels indicate poor ventilation. Multiple restaurants, two hotels, two major shopping centres, several university buildings, a pharmacy and a GP consulting suite had CO₂ levels well above best practice and also above the absolute maximum mandated in the National Construction Code.

Relative humidity readings of less than 40% associated with both heating and cooling air are also of concern. Evidence now suggests low humidity is associated with transmission.

If anyone had COVID-19 in these environments, particularly if people were in them for an extended period, as might happen at a restaurant or pub, there would be a risk of a super-spreader event. Less than 20% of individuals produce over 80% of infections.




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Many aged-care deaths were connected

It appears a relatively small number of super-spreader events, probably associated with airborne transmission of SARS-CoV-2, the virus that causes COVID-19, were responsible for most of the deaths in Victorian aged-care facilities.

Of the 907 people who have died of COVID-19 in Australia, 746, or 82% of COVID-19 deaths, were associated with aged care. In Victoria, there were 52 facilities with more than 20 infections. Three had over 200 infections. As a result, 639 of the 646 aged care residents who died in Victoria were located in just 52 facilities.

But official advice hasn’t changed

Aged-care operators and the states based their infection control on the advice of the Commonwealth Infection Control Expert Group (ICEG). As of September 6, the Coronavirus (COVID-19) Residential Aged Care Facilities Plan for Victoria stated:

Coronavirus (COVID-19) is transmitted via droplets, after exposure to contaminated surfaces or after close contact with an infected person (without using appropriate PPE). Airborne spread has not been reported [our emphasis] but could occur during certain aerosol-generating procedures (medical procedures which are not usually conducted in RACF). […] Respiratory hygiene and cough etiquette, hand hygiene and regular cleaning of surfaces are paramount to preventing transmission.

In early August, more than 3,000 health workers had signed a letter of no confidence in ICEG. The letter noted that aerosol transmission was causing infections in medical staff, many of whom worked in aged-care facilities.

On September 7, we wrote to the federal aged care minister, Richard Colbeck, drawing attention to our August 20 article in The Conversation, which referenced a July 8 article in Nature. The Nature article identified an emerging consensus that aerosol transmission of SARS-CoV-2 is probable in low-ventilation environments.




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The director of the Aged Care COVID-19 Measures Implementation Branch wrote back on Colbeck’s behalf on September 28 saying:

Current evidence suggests COVID-19 most commonly spreads from close contact with someone who is infectious. It can also spread from touching a surface that has recently been contaminated with the respiratory droplets (cough or sneeze) of an infected person and then touching your eyes, nose or mouth.

In other words, Commonwealth authorities were still playing down the significance of airborne transmission nearly two months after the letter of no confidence was sent to ICEG and three months after the article in Nature. By the end of September, Victorian aged-care facilities had reported over 4,000 cases of COVID-19, about half of them in staff.

On October 23, ICEG was still saying:

There is little clinical or epidemiological evidence of significant transmission of SARS-CoV-2 (the virus that causes COVID-19) by aerosols.

Focus on the ‘3 Vs’ to reduce risks

The key thing we need to do until a vaccine is rolled out is to try to prevent indoor super-spreader events. According to the University of Nebraska Medical Centre, we should remember the “three Vs” that super-spreader events have in common:

Venue: multiple people indoors, where social distancing is often harder

Ventilation: staying in one place with limited fresh air

Vocalization: lots of talking, yelling or singing, which can aerosolize the virus.

Measuring indoor ventilation is quick and easy using a carbon dioxide detector. Any CO₂ reading of over 800 parts per million is a cause for concern – the level for air outside is just over 400ppm.

There is no excuse for governments, health authorities and building owners not to monitor ventilation levels to help ensure members of the public are as safe as is reasonably practicable when indoors.

There is also no excuse for the Australian Building Control Board not to change the National Construction Code to require fall-back mechanical ventilation systems be fitted and CO₂ and humidity monitored in all buildings frequented by the public, particularly aged-care facilities.

With the knowledge we have now and a low rate of community infection, Australia should be able to make it through to vaccine roll-out with relatively few further infections and deaths. But that depends on being vigilant about the quality of ventilation indoors and the associated possibility of super-spreader events. This is especially important in aged-care facilities and quarantine hotels.

It’s probably a good idea for us all to open the windows and let the fresh air in.The Conversation

Geoff Hanmer, Adjunct Professor of Architecture and Bruce Milthorpe, Emeritus Professor, Faculty of Science, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How to reduce COVID-19 risk at the beach or the pool


Brett Mitchell, University of Newcastle and Philip Russo, Monash University

Australians are emerging from winter and, where possible, enjoying trips to beaches and public pools. Beach-side picnics, barbecues and get-togethers are back on the cards for many of us.

While daily COVID-19 case numbers have been looking promising in most places lately, we are still very much in a pandemic; your spring and summertime social activities might look a little different this year.

Here’s how to stay safe if you’re planning a trip to the beach or public pool.




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A person swims laps in a pool.
Your spring and summertime social activities might look a little different his year.
Shutterstock

The three golden rules

Outdoor activities are associated with reduced COVID-19 transmission risk compared to indoor activities. That said, whatever your plans, the three golden rules still apply: stay home if you are sick, keep up the hand hygiene and maintain physical distancing from others.

If you’re sick, you shouldn’t be socialising at all. You should be getting a COVID-19 test and self-isolating while you wait for results. Even outdoors, one sick person can spread COVID-19 to a large number of people.

Going to the beach

Firstly, pick a quieter beach. The extra time it takes to research and travel to a more secluded beach may be a hassle, but it’s less risky than going to a crowded beach (and often nicer, too).

Consider driving or cycling to the beach (if possible) rather than taking public transport. If you do use public transport, pick an off-peak time of day and wear a mask — avoid rush hour.

When you arrive, put your towels down in a spot on the sand at least 1.5m away from others — more is better, if you can. You should still swim between the flags, but you don’t need to be sitting close to other people.

An aerial shot of an ocean pool.
Pick a quieter swim spot or go at a less busy time.
Shutterstock

When swimming between the flags, it might feel crowded in the water during busy times or at busy beaches. If you are in that situation, think about reducing the time spent in the water — go in for five minutes, then come out for a bit, then go back in for another five, so you are not having prolonged contact next to another person.

If you see someone expelling mucus into a wave, try to avoid that wave and person if you can.

Remember to stay COVID-safe if you’re at a cafe for a post-swim snack or ice-block. Don’t bunch up in lines close to other people and maintain physical distance from others if you are sitting down for a meal.

In the past, it might have felt normal to share a plate of hot chips with mates or even offer a friend a sip of your drink — but we don’t do that anymore. If you’re having a beach-side picnic, make sure you’re not sharing utensils, double-dipping in the hummus or sticking your fingers into a shared bowl of olives.

Of course, all these general principles also apply to other outdoor swimming locations, such as rivers and dams.

Going to the pool

The ocean is probably less risky than going to the pool, because there’s more movement of water and a high level of dilution.

So you need to approach public pools with a degree of caution.

But if you have no choice, are living away from the coast and want a swim, it’s probably fine to go to an outdoor pool — especially if you are living in an area with a low level of community transmission. You can find out community transmission rates in your area from your state health department website.

Outdoor pools are less risky than indoor pools because of increased air flow. Confined spaces are associated with increased risk of COVID-19 transmission.

An outdoor pool in Sydney.
Outdoor pools are less risky than indoor pools,
Shutterstock

Choose the right time to go a pool. Transmission risk decreases with fewer people, so try to go at less busy times. In the morning, the pool water has likely had time to be well-filtered and well-chlorinated overnight and not many people have swum in it yet that day.

Chlorine kills coronavirus. The CDC says it is

not aware of any scientific reports of the virus that causes COVID-19 spreading to people through the water in pools, hot tubs, or water playgrounds […] including saltwater pools.

The risk of transmission, albeit potentially low, would also depend on how chlorinated the pool is and how long any coronavirus that may be in the water is exposed to chlorine before coming into contact with another person.

Theoretically, if someone is carrying the virus and some mucus goes out of their mouth and into the pool, there might be a certain period of time before any virus in that mucus is inactivated by the chlorine. If it gets to you before that inactivation happens, then it is possibly a bit more risky.

People swim at a pool in Sydney.
Whatever you have planned this summer, think about the local risks and what you can do to reduce them.
Shutterstock

Avoiding the change-rooms is another way to reduce risk, as these rooms are often in a confined space. Being careful to maintain physical distancing in the pool, poolside and at the cafe are also important measures.

In general, it should be fine to take the kids to the pool but, if there was a degree of community transmission in your area, perhaps reconsider. There is growing evidence kids are less susceptible to COVID-19 compared to adults but it doesn’t necessarily mean they are not transmitting it.

Whatever you have planned this summer, think about the local risks and what you can do to reduce them.




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The Conversation


Brett Mitchell, Professor of Nursing, University of Newcastle and Philip Russo, Associate Professor, Director Cabrini Monash University Department of Nursing Research, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Morrison government to invest $211 million in fuel security to protect against risk and price pressures


Michelle Grattan, University of Canberra

The Morrison government is acting to protect Australia’s fuel security as the international outlook becomes more uncertain and prices will be under increasing pressure.

Under the plan, operating through market and regulatory measures, the government will invest $211 million in new domestic diesel storage facilities, changes to create a minimum onshore stockholding, and support for local refineries.


Treasury

Announcing the program with Energy Minister Angus Taylor, Scott Morrison said the changes “will ensure Australian families and businesses can access the fuel they need, when they need it, for the lowest possible price”.

Australia’s fuel supplies are always potentially vulnerable to international instability, something that the pandemic – with its disruption to supply chains – has just reinforced. Local refineries are also under economic pressures, with potential consequences for prices.

The measures are:

  • a $200 million investment in a competitive grants program to build an extra 780 megalitres of onshore diesel storage with industry

  • creation of a minimum stockholding obligation for key transport fuels, and

  • working with refiners on a market design process for a refining production payment.

The government is seeking to have the $200 million grants for new storage matched by state governments or industry. Its focus will be on projects in strategic regional locations, connected to refineries and with connections to existing fuel infrastructure.

Morrison said fuel security was essential for Australia’s national security and the country was fortunate there hadn’t been a significant supply shock in more than 40 years. Fuel security underpinned the entire economy, and the industry itself supported thousands of workers, he said. “This plan is also about helping keep them in work.”

Taylor acknowledged the pressure refineries are under.

The government says modelling indicates a domestic refining capability is worth some $4.9 billion over a decade to Australian consumers is terms of price suppression.

The construction of diesel storage will support up to 950 jobs, with 75 new ongoing jobs, many in the regions, the government says.

“A minimum stockholding obligation will act as a safety net for petrol and jet fuel stocks and increased diesel stockholdings by 40%,” Morrison and Taylor said in their statement.

They stressed the government’s commitment to onshore refining capacity. The industry’s viability is under threat.

The planned production payment scheme is to protect from an estimated 1 cent per litre rise that, according to modelling, would hit fuel if all refineries onshore were to close. Refineries receiving the support will have to commit to stay operating locally.

Under the minimum stockholding requirements, petrol and jet fuel stocks would be kept no lower than current commercial levels, which are about 24 consumption days.

Diesel stocks would increase by 40%, to be at 28 consumption cover days. This would add about 10 days to Australia’s International Energy Agency compliance total.

In July Australia had 84 IEA days including stocks on water. Implementing a minimum stock holding obligation would bring Australia into line with most IEA members which regulate their fuel industries to meet their security needs. Under the IEA treaty member countries are required to have 90 days of stocks.

(IEA days and consumption cover days are different.)

Refineries will be exempt from the obligations to hold additional stocks.

The production payments will ensure a minimum value of 1.15 cents per litre to refineries. A competitive process will determine the location of new storage facilities.

The government says it recognises “the future refining sector in Australia will not look like the past. However, this framework will ensure the market is viable for both our future needs and can support Australia during a severe fuel disruption.”The Conversation

Michelle Grattan, Professorial Fellow, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Type 2 diabetes: eating a diet rich in fruit and vegetables daily lowers risk, study shows



The more fruit and vegetables consumed, the lower the risk.
Anna Shkuratova/ Shutterstock

Nita Forouhi, University of Cambridge; Ju-Sheng Zheng, Westlake University, and Nick Wareham, University of Cambridge

Eating about five servings of fruit and vegetables a day is widely promoted as a key part of a healthy diet. This is because consuming fruit and vegetables is linked to lowering the risk of health problems such as coronary heart disease, stroke and some types of cancer.

But there’s still confusion about the role that fruit and vegetables have in preventing type 2 diabetes. Evidence from research has been inconsistent, partly because most studies have relied on participants remembering what they ate – which can be inaccurate. But our latest research found that people who regularly ate more fruit and vegetables in their diet had half the risk of developing type 2 diabetes compared to those who ate less.

Since research shows that type 2 diabetes can be prevented through a healthy diet, we wanted to know just how important eating fruit and vegetables is as part of that. We conducted the world’s largest study that measured blood levels of vitamins linked to fruit and vegetable consumption in a population. This method of using objective nutritional biomarkers – indicators of dietary intake, metabolism or nutritional status that are present in our blood – cuts out the errors and inaccuracies that affected previous studies. We also asked people to report what specific foods they ate to compare with the biomarker data.

We followed a group of 340,234 people from eight European countries. We specifically studied biomarkers in 10,000 people who developed type 2 diabetes during follow-up and compared them with 13,500 people who didn’t.

The biomarkers we measured were levels of vitamin C and six different carotenoids or plant pigments in the blood. These biomarkers tell us about the fruit and vegetables a person gets in their diet. We then calculated the total sum of these seven nutrient biomarkers as a composite score, then split scores into five categories ranging from lowest consumption to highest.

We found that the higher the biomarker score level, the lower the risk of future type 2 diabetes. People whose biomarker score was in the top 20% of the population had a 50% lower risk of developing type 2 diabetes compared to those with lower scores. We also found that eating around 66 grams of fruit and vegetables daily could potentially cut risk of type 2 diabetes by a quarter.

One to two portions daily cut risk by a quarter.
Rawpixel.com/ Shutterstock

Our findings build upon the results of a smaller study of 21,831 people living in England, 735 of whom developed type 2 diabetes. This study showed a strong link between higher blood vitamin C level and lower risk of diabetes. But the link was weaker when examining fruit and vegetable intake as reported by the participants. By repeating this work on a larger scale and in several countries, our results further strengthen evidence that these results are likely to be repeated in other populations, too.

Five a day

Since UK dietary guidelines consider each portion of fruit or vegetable to be 80 grams, our study shows eating even one portion per day could have health benefits. For instance, seven cherry tomatoes, two broccoli spears, or one banana would all roughly equal one portion.

Although “five a day” has been around for decades, fruit and vegetable consumption remains low. Only one in seven people over 15 eat at least five portions everyday – and one in three people don’t eat any daily. Encouragingly, our results show there are large potential benefits from making small changes to our diets.

Our research highlights that reduced risk isn’t just because of certain nutrients or vitamins. Rather, the benefits we observed are because of the combination of multiple beneficial components found in fruits and vegetables. Alongside vitamin C and carotenoids, other components including fibre, potassium and polyphenols, which have beneficial effects on weight, body inflammation, blood sugar levels, and keep gut bacteria healthy. And a diverse variety of fruit and vegetables has the greatest health benefits, as you consume more of these beneficial components.




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We also took into account how several factors – including age, gender, body mass index, education level, occupation, smoking, alcohol intake, physical activity and use of vitamin supplements – all affected the risk of type 2 diabetes. We found that the biomarker results linked to fruit and vegetables were independent of these other factors – so regardless of whether a person smoked or was physically active, eating a diet rich in more fruit and vegetables is relevant for lowering the risk of developing type 2 diabetes.

Our research doesn’t establish cause and effect, because we did not intervene with dietary change – rather we observed what happened over time to participants with different blood biomarker levels. But, by using these objective measures and a large sample size in different countries with varying diets, our confidence in these findings is increased. We still don’t yet know whether our findings would be different among different ethnic groups, which should be a focus of future research.

It’s well known that fruit and vegetables are an important part of maintaining good health throughout life, but we also know that in reality the majority of people do not eat enough of them. Our study shows that even just a small increase in the amount of fruits or vegetables you get in your diet can significantly reduce your risk of developing type 2 diabetes.The Conversation

Nita Forouhi, Programme Leader, MRC Epidemiology Unit, University of Cambridge; Ju-Sheng Zheng, Principal Investigator, Human Nutrition and Epidemiology, Westlake University, and Nick Wareham, Director of the MRC Epidemiology Unit, University of Cambridge

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Victorians, and anyone else at risk, should now be wearing face masks. Here’s how to make one


C Raina MacIntyre, UNSW; Kerryn Phelps, Western Sydney University; Lisa Maher, UNSW, and Shovon Bhattacharjee, UNSW

After early success in suppressing COVID-19, we are facing a resurgence in Victoria, which is threatening disease control for the whole country.

Outbreaks in northwestern Melbourne, including in public housing tower blocks in inner Melbourne, and now in the twin border towns of Albury-Wodonga, signal a risk of losing our hard-won gains. These gains have already come at a heavy price to the economy and mental health, which is all the more reason to throw everything we can at this resurgence – including widespread use of face masks, as we have seen in other countries such as the United States and United Kingdom.

With 191 new cases announced on July 7, Victorian Premier Daniel Andrews has announced a return to stage 3 restrictions for six weeks from July 9 for metro Melbourne and Mitchell Shire. This means residents will be confined to their homes except for essential trips such as work, medical care, exercise or shopping for essentials. The evidence suggests both sick and healthy people wearing masks will help curb the spread of COVID-19 during this precarious time.




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Australia is one of the few countries that has suppressed COVID-19 after a peak in disease incidence in late March. The current resurgence, unlike the peak in March which was largely travel-related, has arisen mostly from community transmission, which is a more serious concern.

Health authorities have a range of measures at their disposal, including expanded testing to find all new cases, diligent contact tracing, travel bans, border closures and quarantine of returning travellers. As members of the public, there are five main things we can do to stop the spread: get tested if we have symptoms, download the COVIDSafe App, practise physical distancing, wash our hands often, and wear a face mask.

Why masks help

The most extreme form of physical distancing is a lockdown, already enforced in Melbourne. Keeping at least 1.5 metres away from others also dramatically reduces the risk of COVID-19, even in crowded households. Victorians should think about wearing a mask, especially in indoor spaces like shops or public transport or in outdoor crowds. There may be epidemics developing in other states, so people at risk in those states should think about masks too.

There’s no doubt masks help stop the spread. A recent study commissioned by the World Health Organisation showed that face masks reduce the risk of infection with viruses such as SARS-CoV-2, the coronavirus that causes COVID-19, by 67% if a disposable surgical mask is used, and up to 95% if specialist N95 masks are worn, although these are not widely available to the public.

This study prompted the WHO to change its position to recommending community mask use. It had long advised masks should be worn only by sick people to stop them infecting others, although this was perhaps motivated in part by concerns over supplies.

Many countries, perhaps most notably the United States, initially adopted this advice but then began to encourage community-wide mask use when the epidemic began to get out of hand.

Why not in Australia?

Australia has not yet adopted community masking as a tool in the fight against COVID-19. The WHO issued a long list of dangers of mask wearing, including that masks give “a false sense of security, leading to potentially lower adherence to other critical preventive measures such as physical distancing and hand hygiene”.

There is no scientific evidence to support this – in fact, the evidence suggests the opposite. In an illustrative exercise, Italian researcher Massimo Marchiori found people stayed more than twice as far away from him when he wore a mask.

Not all masks are the same, however. For community use, the options are surgical masks and cloth masks. Surgical masks are single-use only and should not be re-used. If they are unavailable or too expensive, you can make an effective cloth version yourself if you follow a few key principles.




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Cloth masks can vary widely depending on the material and design – a single or even double-layered mask or bandanna is likely not protective at all.

A cloth mask should have at least three or four layers, including a water-resistant outer layer, a fine weave and high thread count, and should be washed and worn fresh each day. It should fit snugly around your face, or air will flow through the gaps on the sides. A nylon stocking over the top can help.

Research shows a 12-layered cloth mask can be as good as a surgical mask, although you may not have the time or inclination to make a homemade version with 12 layers.

How to make an effective cloth mask.
Shovon Bhattacharjee, Author provided

Modelling shows that even a modestly effective mask that delivers just a 20% reduction in viral transmission can successfully flatten the COVID-19 curve. Masks have a double benefit, stopping infected people spreading the virus and protecting uninfected people from catching it.

Given the possibility this coronavirus can also be spread by people without symptoms or even people who have already left the room, handwashing and physical distancing may not be enough. We need every tool at our disposal, and that includes masks.




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Masks can be worn in public or indoors. Surgical masks worn at home can prevent the spread of the coronavirus to family members, which may be worth considering if you live with a health worker or someone else at high risk.

As Melbourne and Australia struggle to regain control of COVID-19, positive promotion of face masks, and simple how-to guides for making, as well as wearing and removing them could be a powerful addition to our armoury. A clear, consistent public health directive in relation to masks is needed now to help avoid longer lockdowns and more draconian measures, and enable safer community activities.The Conversation

C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW; Kerryn Phelps, Adjunct Professor, NICM Health Research Institute, Western Sydney University; Lisa Maher, Professor, Faculty of Medicine, UNSW, and Shovon Bhattacharjee, PhD Candidate, The Kirby Institute, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.