Most people don’t benefit from vaccination, but we still need it to prevent infections



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Everyone has to be vaccinated for immunisation programs to work.
from http://www.shutterstock.com

Allen Cheng, Monash University

A recent article in The Conversation questioned whether we should all get flu vaccinations, given 99 people would have to go through vaccination for one case of flu to be prevented.

But this position ignores the purpose of immunisation programs: whole populations of people need to take part for just a small number to benefit. So how do we decide what’s worth it and what’s not?




Read more:
The flu vaccine is being oversold – it’s not that effective


Decision-making in public health

When we consider a treatment for a patient, such as antibiotics for an infection, we first consider the evidence on the benefits and potential harms of treatment. Ideally, this is based on clinical trials, where we assume the proportion of people in the trial who respond represents the chance an individual patient will respond to treatment.

This evidence is then weighed up with the individual patient. What are the treatment options? What do they prefer? Are there factors that might make this patient more likely to respond or have side effects? Is there a treatment alternative they would be more likely to take?

In public health, the framework is the same but the “patient” is different – we are delivering an intervention for a whole population or group rather than a single individual.

We first consider the efficacy of the intervention as demonstrated in clinical trials or other types of studies. We then look at which groups in the population might benefit the most (such as the zoster vaccine, given routinely to adults over 70 years as this group has a high rate of shingles), and for whom the harms will be the least (such as the rotavirus vaccine, which is given before the age of six months to reduce the risk of intussusception, a serious bowel complication).

Compared to many other public health programs, immunisation is a targeted intervention and clinical trials tell us they work. But programs still need to target broad groups, defined by age or other broad risk factors, such as chronic medical conditions or pregnancy.




Read more:
Explainer: what is herd immunity?


Risks and benefits of interventions

When considering vaccination programs, safety is very important, as a vaccine is being given to a generally healthy population to prevent a disease that may be uncommon, even if serious.

For example, the lifetime risk of cervical cancer is one in 166 women, meaning one woman in 166 is diagnosed with this cancer. So even if the human papillomavirus (HPV) vaccine was completely effective at preventing cancer, 165 of 166 women vaccinated would not benefit. Clearly, if we could work out who that one woman was who would get cancer, we could just vaccinate her, but unfortunately we can’t.

It’s only acceptable to vaccinate large groups if clinically important side effects are low. For the HPV vaccine, anaphylaxis (a serious allergic reaction) has been reported, but occurs at a rate of approximately one in 380,000 doses.

An even more extreme case is meningococcal vaccination. Before vaccination, the incidence of meningococcal serogroup C (a particular type of this bacterium) infection in children aged one to four years old was around 2.5 per 100,000 children, or 7.5 cases for 100,000 children over three years.

Vaccination has almost eliminated infection with this strain (although other serotypes still cause meningococcal disease). But this means 13,332 of 13,333 children didn’t benefit from vaccination. Again, this is only acceptable if the rate of important side effects is low. Studies in the US have not found any significant side effects following routine use of meningococcal vaccines.

This is not to say there are no side effects from vaccines, but that the potential side effects of vaccines need to be weighed up against the benefit.

For example, Guillain Barre syndrome is a serious neurological complication of influenza vaccination as well as a number of different infections.

But studies have estimated the risk of this complication as being around one per million vaccination doses, which is much smaller than the risk of Guillain Barre syndrome following influenza infection (roughly one in 60,000 infections). And that’s before taking into account the benefit of preventing other complications of influenza.




Read more:
Is the end of Zika nigh? How populations develop immunity


High schools are bigger, so immunisation is easier than at primary schools.
from http://www.shutterstock.com

What other factors need to be considered?

We also need to consider access, uptake and how a health intervention will be delivered, whether through general practices, council programs, pharmacies or school-based programs.

Equity issues must also be kept in mind: will this close the gap in Indigenous health or other disadvantaged populations? Will immunisation benefit more than the individual? What is the likely future incidence (the “epidemic curve”) of the infection in the absence of vaccination?

A current example is meningococcal W disease, which is a new strain of this bacteria in Australia. Although this currently affects individuals in all age groups, many state governments have implemented vaccination programs in adolescents.

This is because young adults in their late teens and early 20s carry the bacteria more than any other group, so vaccinating them will reduce transmission of this strain more generally.

But it’s difficult to get large cohorts of this age group together to deliver the vaccine. It’s much easier if the program targets slightly younger children who are still at school (who, of course, will soon enter the higher risk age group).

In rolling out this vaccine program, even factors such as the size of schools (it is easier to vaccinate children at high schools rather than primary schools, as they are larger), the timing of exams, holidays and religious considerations (such as Ramadan) are also taken into account.




Read more:
What is meningococcal disease and what are the options for vaccination?


For government, cost effectiveness is an important consideration when making decisions on the use of taxpayer dollars. This has been an issue when considering meningococcal B vaccine. As this is a relatively expensive vaccine, the Pharmaceutical Benefits Advisory Committee has found this not to be cost effective.

This is not to say that meningococcal B disease isn’t serious, or that the vaccine isn’t effective. It’s simply that the cost of the vaccine is so high, it’s felt there are better uses for the funding that could save lives elsewhere.

While this might seem to be a rather hard-headed decision, this approach frees up funding for other interventions such as expensive cancer treatments, primary care programs or other public health interventions.

Why is this important?

When we treat a disease, we expect most people will benefit from the treatment. As an example, without antibiotics, the death rate of pneumonia was more than 80%; with antibiotics, less than 20%.

The ConversationHowever, vaccination programs aim to prevent disease in whole populations. So even if it seems as though many people are having to take part to prevent disease in a small proportion, this small proportion may represent hundreds or thousands of cases of disease in the community.

Allen Cheng, Professor in Infectious Diseases Epidemiology, Monash University

This article was originally published on The Conversation. Read the original article.

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The flu vaccine is being oversold – it’s not that effective



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The protection of the flu vaccine is minimal, and may not be worth it.
from shutterstock.com

Chris Del Mar and Peter Collignon, Australian National University

Winter has started, and with it, flu season. Inevitably, all of us (young, old and sick) have been implored to be immunised against influenza, with some eligible for a subsidised vaccine. And people are heeding the message, to the point that there is now a shortage of available vaccines.

At the same time, findings from three important Cochrane reviews on the effectiveness of the influenza vaccination aren’t consistent with the advice we’re been given.

Cochrane reviews are independent systematic reviews, which are comprehensive analyses of most of the literature relevant to a research topic. Cochrane reviews summarise the results in a multitude of studies, and are regularly updated to absorb new research.

These three Cochrane reviews have been recently updated, as well as stabilised, which is what happens when it looks as if it seems unlikely new research would be published that would change the conclusions.

What the reviews found

The first Cochrane review looked at the effects of the influenza vaccine in healthy adults from 25 studies conducted over single influenza seasons in North America, South America, and Europe between 1969 and 2009. It found the vaccine reduced the chance of getting laboratory confirmed influenza from 23 cases out of 1,000 to 9 cases out of 1,000.

While this seems to be a reduction of more than 50%, that seems less optimistic expressed in absolute terms.

The infection rate in adults drops from 2% per year to 1%. You could say that’s halved, but it effectively only drops by 1%. So this means that out of every 100 healthy adults vaccinated, 99 get no benefit against laboratory confirmed influenza.




Read more:
What you need to know to understand risk estimates


The second Cochrane review – which looked at trials in children over single influenza seasons in the US, Western Europe, Russia, and Bangladesh between 1984 and 2013 – found similar results.

The third Cochrane review looked at vaccines for the elderly in nursing homes. It found much less good evidence, with only one randomised trial – considered the gold standard in clinical trials as it establishes causation rather than correlation.

While observational studies (that draw inferences from a population to establish associations) have been done to show benefits of the vaccines, bias means we cannot rely on their results.

There are also potential harms from influenza vaccines noted in the reviews. They range from serious (a neurological disease called Guillain Barre) through to moderate (fevers, in children especially – some of which will cause febrile convulsions), and trivial (a sore arm for a couple of days).

Why are we so scared of the flu?

There is a special concern about influenza from a public health point of view. This comes about from its potential to cause pandemics. The first in modern history was the Spanish influenza pandemic of 1918-19, when tens of millions of people died worldwide.

There’s good evidence to show face masks protect against influenza.
from shutterstock.com

There have also been been several, less severe pandemics. These include the most recent swine flu that, although while affecting some (unexpected) groups of people (including pregnant women, those who were obese, and had asthma), caused little more effect on the overall population than the usual seasonal influenza.




Read more:
Four of the most lethal infectious diseases of our time and how we’re overcoming them


Public health experts worry about another pandemic that can be more harmful and contagious, which could be devastating. But it’s important to note the vast majority of deaths from Spanish influenza were from secondary bacterial infections and predated the antibiotic era.

The reasons influenza virus has this ability to cause new pandemics comes from its instability – it changes genetically easily, making it more difficult for our immune systems to recognise newer strains. The effect is that new vaccines must be prepared every year for a best-guess at next year’s virus, and we need vaccination every year.

Influenza can also undergo a more radical change, such as when a new form of the virus emerges from an animal host (wild or domesticated birds or pigs, for example). This moving target makes it more difficult to vaccinate against – especially with the genetic shifts of pandemics. Just when we need protection most, vaccines can provide it least.

So what, if not the vaccine?

There are physical barriers that can prevent the spread of influenza. These are the masks (to reduce the spread of aerosol-borne virus particles), hand washing (to reduce the spread if virus from hands onto shared surfaces), and quarantine measures (isolating infected people to reduce their infectivity).




Read more:
I’ve always wondered: why many people in Asian countries wear masks, and whether they work


The ConversationThere is now reasonable evidence such measures reduce infections considerably. It might take a bit of effort to change the psyche of Australians to make wearing a facemask acceptable if you have an acute respiratory infection. Even the heroic “soldiering on to work” (or school) with your virus needs to be reversed as a public health act.

Chris Del Mar, Professor of Public Health and Peter Collignon, Professor, infectious diseases and microbiology, Australian National University

This article was originally published on The Conversation. Read the original article.

Here’s why flu vaccinations should be mandatory for Aussie health workers in high-risk areas



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Despite the numerous campaigns promoting the flu vaccine to Australian health workers, uptake has been documented to range from only 16-60%.
Tatiana Chekryzhova/Shutterstock

C Raina MacIntyre, UNSW and Holly Seale, UNSW

On June 1, health workers in New South Wales will be required to have a flu vaccination if they work in high-risk clinical areas, such as wards for neonatal care, transplants and cancer. Otherwise staff are required to wear surgical masks during the flu season or risk being redeployed.

NSW is the only state to make flu vaccination mandatory for some health workers. It aims to protect vulnerable patients and the health system from another disastrous flu season like in 2017. While the federal government has told aged care providers they must offer the flu vaccine to their staff this winter, there is no requirement for staff to accept the vaccine.

Despite the numerous campaigns promoting the flu vaccine to Australian health workers, uptake has been documented to range from only 16-60%, with an even lower rate reported among aged-care workers.




Read more:
Protecting our elderly: beating flu outbreaks in nursing homes


The most effective way to improve vaccination rates among health workers is to make it mandatory. State, territory and Commonwealth governments should consider making the flu shot mandatory for all health workers in high-risk clinical areas and aged care facilities.

Why health workers need to be vaccinated

For most of us, vaccination is for individual protection. In the case of those caring for sick and vulnerable people such as children and the elderly, vaccination protects others from devastating illness, complications and even death.

Hospitals and aged care facilities can experience explosive outbreaks of influenza.
Aged care facilities may have to close their doors to new admissions, which can also have a significant economic impact. It’s also important that staff absenteeism in hospitals is kept low, especially in areas with limited specialist expertise.

Some argue vaccination of health workers is a moral duty, while others state individual freedom of choice is more important than protection of patients.

Mandating vaccination

The use of immunisation mandates for health-care workers is not new in Australia. In most states and territories, staff are required to have vaccines for (or show evidence of protection against) measles, mumps, rubella, diphtheria, tetanus, pertussis, hepatitis B, and varicella (chicken pox).

NSW, for example, introduced mandatory vaccination of health care workers for several vaccines (but not the flu) in 2007. NSW health workers generally accepted this change in policy, with only 4% objecting.

Making the flu shot mandatory, as NSW has done this year, would simply add the the list of vaccinations health workers are required to have.

NSW is the only state to make flu vaccination mandatory for some health workers.
from http://www.shutterstock.com

The evidence suggests it’s worth it; a five-year study in one hospital in the United States showed mandatory hospital policies can raise coverage rates to close to 100%.

Institutions that have implemented a mandatory policy have dramatically reduced employee sick days as well as flu in hospitals, thereby improving patient safety and reducing health care costs.

Staff vaccination programs

Most workplaces run intensive vaccination programs, which may include mass immunisation clinics, mobile carts, posters and email reminders. But in most cases, these programs aren’t successful at boosting vaccination levels above 60%.

Some hospitals have been able to achieve higher vaccination rates in the short term through easy access to vaccines, education, reminders and multiple opportunities for vaccination. But these initiatives require ongoing resources and continual efforts – a one-off vaccination day is not enough.




Read more:
Flu vaccine won’t definitely stop you from getting the flu, but it’s more important than you think


The Victorian health system used a slightly different approach in 2014 when it made high rates of flu vaccination a hospital performance target. The government also provided the vaccine free to all Victorian hospitals.

This raised vaccination rates among Victorian hospital staff from 60% to 75% overall (higher in some hospitals). But higher rates may be achieved through mandatory flu vaccination.

But it’s not always the best policy

For each situation, we need to consider the overall risks and benefits of mandatory vaccination, as well as the gains in protection and vaccination coverage.

For infant vaccination, for example, vaccination rates are already at a high baseline of more than 93%. So, the risk of coercive policies may be greater than the relatively small gains achieved by coercive methods. Similar results may be achieved through other methods.

There’d be little point mandating vaccines for infants since they already have high rates of vaccination.
from http://www.shutterstock.com

In the case of health and aged-care workers, however, we start with a lower base of vaccine coverage, of 16-60%. Adding financial incentives or disincentives, or making it mandatory, would result in much larger gains in vaccination rates.

Vaccinating health-care workers also has benefits beyond their individual protection: it reduces the risk of their patients contracting influenza and maintains the health workforce capacity. This shifts the balance in favour of mandatory vaccination.

The ConversationGiven large potential gains and low resource requirements, mandatory flu vaccination for all health workers in high-risk areas is a good idea. Governments should consider this and other strategies to improve flu vaccination rates health and aged care workers.

C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, UNSW and Holly Seale, Senior Lecturer, UNSW

This article was originally published on The Conversation. Read the original article.

Explainer: what’s new about the 2018 flu vaccines, and who should get one?


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The flu shot is free for at-risk groups, and available to others for around $10-$25.
Shutterstock

Kanta Subbarao, The Peter Doherty Institute for Infection and Immunity

As winter draws closer, many Australians are wondering whether this year’s influenza season will be as bad as the last, and whether they should get vaccinated.

For most of us, influenza (the flu) is a mild illness, causing fever, chills, a cough, sore throat and body aches, that lasts several days. But some people – especially the elderly, young children and those with chronic diseases – are at risk of serious and potentially deadly complications.

While not perfect, the seasonal influenza vaccine is the best way to protect against influenza viruses. It’s free for at-risk groups, and available to others for around A$10A$25 (plus a consultation fee if your GP doesn’t bulk bill). In some states people can also get influenza vaccines from pharmacies.

Different viruses

There are four influenza viruses that cause epidemics: two type A viruses, called A/H1N1 and A/H3N2 and two type B influenza viruses, called B/Yamagata and B/Victoria viruses. All four cause a similar illness called influenza.

In any season, one of the viruses may dominate, or two or even three viruses could circulate.




Read more:
Influenza: The search for a universal vaccine


Last year’s influenza seasons in Australia and the United States were caused by A/H3N2, while B/Yamagata viruses predominated in Asia, and a mix occurred in Europe.

Influenza A/H3N2 viruses cause more severe epidemics that affect the entire population, from the very young to the very old.

In contrast, influenza B and A/H1N1 viruses tend to cause disease in children and young adults, respectively, sparing the elderly.

Developing the vaccine

Although influenza activity around the world is monitored throughout the year, influenza viruses mutate continuously and we can’t predict which virus will dominate. For this reason, the influenza vaccine includes components that are updated to protect against all four influenza A and B viruses.

Vaccination is the best option to prevent influenza and is offered in the autumn, in anticipation of influenza season in the winter. Typically, the influenza season begins in June, peaks by September and can last until November.

For best protection, you need a flu vaccine each year. Roberty Booy, Head of the Clinical Research team at the National Centre for Immunisation Research and Surveillance, explains why (via the Australian Academy of Science).

It takes about two weeks for the vaccine to induce immunity and the resulting protection lasts about six months.

The 2017 influenza season was severe in all states except WA. The epidemic began earlier than usual, there were more reported cases than in previous years, and there were a large number of outbreaks in residential care facilities in several jurisdictions.




Read more:
Here’s why the 2017 flu season was so bad


Who is most affected?

People of all ages can get influenza but some people are at greater risk of severe illness and complications that require hospitalisation. These groups include:

  • older adults who are over 65 years of age
  • children aged under five years and especially children under one
  • pregnant women
  • Aboriginal and Torres Strait Islander persons
  • people with severe asthma or underlying health conditions such as heart or lung disease, low immunity or diabetes.
Anyone can get a flu vaccine but some people have to pay for it.
Shutterstock

While the National Immunisation Program provides vaccines free of charge for the groups listed above, anyone who wants to reduce their risk of influenza can get vaccinated.

What’s new this year?

There are two notable changes.

One change is that several states (Tasmania, Victoria, New South Wales, Queensland, Western Australia and the ACT) are now offering free vaccination for children under five years of age.




Read more:
Thinking about getting your child the flu vaccine? Here’s what you need to know


This is important because children are prone to severe illness and they spread the virus to their contacts, at home and in daycare. Previously, only WA offered children the influenza vaccine free of charge.

The second change is “enhanced” vaccines are available for adults over the age of 65. The standard influenza vaccine is not optimally effective in older adults.

Two products have been developed to improve the immunity offered by the vaccine: one is a high-dose vaccine four times the strength of the standard vaccine and the second is an “adjuvanted” vaccine, that contains an additive that boosts the immune response to the vaccine.




Read more:
Here’s what you need to know about the new flu vaccines for over-65s


These vaccines have been available in other countries for many years but are being introduced in Australia for the first time in 2018. Older adults will be offered one of the two enhanced vaccines for free.

What happens if you still get influenza?

Even if you’re vaccinated, you can still get influenza.

The effectiveness of the seasonal influenza vaccine varies and is usually around 40-50%. But last year’s vaccine was only around 33% effective overall, because it was not effective against the A/H3N2 virus though it was effective against the A/H1N1 and influenza B viruses.

While vaccines are given ahead of time to prevent influenza, antiviral drugs are available via GP prescription for people who get infected.

The antiviral drugs for influenza are most effective when taken within two days of illness and are only effective against influenza viruses. But they’re not effective against other respiratory viruses that cause colds and respiratory symptoms.

Influenza is a contagious virus that spreads through contact with respiratory secretions that are airborne (such as coughs and sneezes) or that contaminate surfaces (after wiping a runny nose, for instance). If you have influenza, stay home to avoid spreading the virus.

The ConversationUnfortunately, we can’t predict whether the 2018 influenza season will be mild or severe. Once we know which virus or viruses are circulating, we may be in a better position to predict how severe the season will be for older adults.

Kanta Subbarao, Professor, The Peter Doherty Institute for Infection and Immunity

This article was originally published on The Conversation. Read the original article.

Hot & Bothered – Cold & Shivering


I came home from work early today – just after 9.00 a.m. actually. Why? Because I’m not too well just at the minute. I’ve had a flu shot earlier in the year, so I’m hoping it is just a cold. Having said that though, my back is really sore ~ one minute I’m hot and bothered ~ the next I’m cold and shivering. I also have a really sore throat and runny snoz … Sounds like a flu-like thing doesn’t it? Frown

So I’m trying to keep rugged up and trying not to get too sick – if that is possible. The problem is, if I do get really sick it may cause me to relapse into the illness I’m forever suffering from – just as I’ve got over it. So that’s the real worry I guess. Still, no use going there in my mind when I’m not there in body – makes sense to me.

DOWN A LITTLE


I have just recently wrote an Email to an old friend and told her that I feel a little down at the moment. I told her it’s hard to put a finger on why it is the case at the moment. I just can’t really explain why I feel down.

I have had all these injuries over the last couple of months that I have got from the place I work (I work fulltime as well as being the pastor of the church), getting over the flu and yet another injury today as well. So I suppose it could be physical.

The other thing is the small size of the church, for which I’m sure I have a right attitude about. But not knowing what exactly is causing my ‘blues,’ I simply can’t rule that out yet as being the thing I’m down about.

Oh well, you just have to soldier on I think through times like these and pray.