Michelle Grattan, University of CanberraAs NSW on Wednesday extended its lockdown for another month and the federal government shelled out more money, it was as if we were back in 2020 and Victoria’s long incarceration.
Thankfully, one big difference is that the Sydney outbreak, where the latest figure is 177 new locally acquired cases, hasn’t had (at least so far) a high death rate.
Some deaths are occurring, including a woman in her 30s, but the nursing homes now seem substantially protected, although there remains concern immunisation of aged care workers has a long way to go.
In its latest funding, the federal government has resisted calls for the reinstatement of JobKeeper, but there is help for both individuals and businesses.
Scott Morrison announced the maximum COVID disaster payment for workers who lose hours would rise from $600 to a maximum of $750 (the original JobKeeper level). There will also be $200 for people on welfare payments who lose more than eight hours work.
The Prime Minister argued JobKeeper did not have the flexibility now required.
JobKeeper was “not the right solution for the problems we have now,” he told his news conference (held at The Lodge, where he’s isolating, with reporters clutching umbrellas).
“What we are doing now is faster [paying the money direct to workers rather than through the employers], it’s more effective, it’s more targeted, it’s getting help where it is needed
far more quickly.
“We’re not dealing with a pandemic outbreak across
the whole country.
“What we need now is the focused effort on where the need is right now. And so it can be turned on and off to the extent that we have outbreaks.
“JobKeeper was a great scheme. But you don’t play last year’s grand final this year. You deal with this year’s challenges.”
The cost of boosting the disaster payment and the welfare top up will depend on how long the NSW lockdown lasts – and what other (if any) future lockdowns occur there or elsewhere.
Under an expanded package for businesses hit by the NSW restrictions, more businesses will be covered, with the maximum turnover threshold increased from $50 million to $250 million.
Those eligible – including not-for-profits – will be able to receive $1,500 to $100,000 a week (compared to $1500 to $10,000 previously).
The government says up to an extra 1,900 businesses employing about 300,000 people could benefit from the widening of eligibility.
The total cost of the NSW package – funded on a 50-50 split with the state – is $600 million a week, up from $500 million in the previous package.
Morrison said Commonwealth support to NSW amounted to $750 million a week.
There is also a new joint federal-state package (funded on a 50-50 basis) to give Victorian small and medium businesses extra support to recover from the recent lockdown. This will total an extra $400 million.
On the vaccine front the NSW government, having failed to get more Pfizer from other states, has decided to divert some Pfizer doses from regional areas to inoculate Year 12 students in the COVID hot spots.
These students will be able to return to face to face learning on August 16.
We’ve yet to see how the reallocation decision will go down in the regions.
Morrison was upbeat in predicting Australia’s economy would bounce back strongly from the lockdown, as it did after the earlier dive. It’s crystal ball territory. The September quarter is set to be negative. The December quarter result is unforeseeable.
Treasurer Josh Frydenberg said what happens in the December quarter, “will largely depend on how successful NSW is in getting on top of this virus.”
The government is trying to judge what it will take to keep the economy out of a second recession, which would likely kill many businesses that just managed to hold on through the earlier one.
A second recession would inflict a major hit on the government politically, just before an election that must be held by May.
A poll done by Utting Research in NSW on Monday underlines the message of other polls: COVID currently is taking serious skin off the PM. Only 37% were satisfied with the job he is doing handling the COVID crisis; 51% were dissatisfied.
Morrison said on Wednesday: “I would expect by Christmas we will be seeing a very different Australia to what we’re seeing now”.
He knows if we don’t, he could be in dire straits.
One case of Lambda was recorded in hotel quarantine in New South Wales in April.
Lambda has now been detected in more than 20 countries around the globe.
In June this year, the WHO designated it a “variant of interest”. This is due to mutations thought to affect the virus’ characteristics, such as how easily it’s transmitted. Though it’s not yet concerning enough for the WHO to deem it a “variant of concern”, such as Alpha or Delta.
Epidemiological evidence is still mounting as to the exact threat Lamda poses. So, at this stage more research is required to say for certain how its mutations impact transmission, its ability to evade protection from vaccines, and the severity of disease.
Preliminary evidence suggests Lambda has an easier time infecting our cells and is a bit better at dodging our immune systems. But vaccines should still do a good job against it.
Is Lambda more infectious? And can it escape vaccines?
What’s more, as many of the coronavirus vaccines currently available or in development are based on the spike protein, changes to the spike protein in new variants can impact vaccine effectiveness
Lambda contains multiple mutations to the spike protein.
One mutation (F490S) has already been associated with reduced susceptibility to antibodies generated in patients who had recovered from COVID. This means antibodies generated from being infected with the original Wuhan strain of COVID aren’t quite as effective at neutralising Lambda.
Another Lambda mutation (L452Q) is at the same position in the spike protein as a previously studied mutation found in the Delta variant (L452R). This mutation in Delta not only increases the ability of the virus to infect cells, but also promotes immune escape meaning the antibodies vaccines generate are less likely to recognise it.
Both mutations F490S and L452Q are in the “receptor binding domain”, which is the part of the spike protein that attaches to our cells.
Preliminary data on the Lambda spike protein suggests it has increased infectivity, meaning it’s more easily able to infect cells than the original Wuhan virus and the Alpha and Gamma variants. These early studies also suggest antibodies generated in people receiving the CoronaVac vaccine (developed by Chinese biotech Sinovac) were less potent at neutralising the spike protein of Lambda than they were the Wuhan, Alpha or Gamma variants.
It’s worth noting infectivity is not the same as being more infectious between people. There’s not enough evidence yet that Lambda is definitely more infectious, but the mutations it has suggest it’s possible.
A separate small study, also yet to be reviewed by the scientific community, suggests the L452Q mutation in the Lambda spike protein is responsible for its increased ability to infect cells. Like the L452R mutation in the Delta variant, this study suggests the L452Q mutation means Lambda may bind more easily to the “ACE2 receptor”, which is the gateway for SARS-CoV-2 to enter our cells.
This preliminary study suggests Lambda’s spike protein mutations reduce the ability of antibodies generated by both Pfizer and Moderna’s vaccines to neutralise the virus. Also, one mutation was shown to resist neutralisation by antibodies from antibody therapy to some extent.
However, these reductions were moderate. Also, neutralising antibodies are only one part of a protective immune response elicited by vaccination. Therefore, these studies conclude currently approved vaccines and antibody therapies can still protect against disease caused by Lambda.
Is it more severe?
A risk assessment released by Public Health England in July concedes there’s not yet enough information on Lambda to know whether infection increases the risk of severe disease.
The risk assessment also recommends ongoing surveillance in countries where both Lambda and Delta are present be implemented as a priority. The aim would be to find out whether Lambda is capable of out-competing Delta.
With ongoing high levels of transmission of the coronavirus, there’s a continued risk of new variants emerging. The Lambda variant again highlights the risk of these mutations increasing the ability of SARS-CoV-2 to infect cells or disrupt existing vaccines and antibody drugs.
The WHO will continue to study Lambda to determine whether it has the potential to become an emerging risk to global public health and a variant of concern.
C Raina MacIntyre, UNSWThe Greater Sydney lockdown began on June 26 and almost a month later, New South Wales is recording around 100 new COVID cases a day. We are also seeing the virus spread well beyond the initial eastern suburbs cluster. The virus then spread from NSW to Victoria resulting in a lockdown there too, followed by South Australia.
Delta is the most contagious of all variants known. The original Wuhan strain was overtaken by the more contagious D614G strain by March 2020, and that virus was responsible for the Victorian second wave.
Then in September, Alpha emerged in the United Kingdom, and was even more contagious. Alpha seemed set to dominate the world by early 2021, but then Delta emerged and swept the world. It has mutations which make it more contagious than Alpha, and more able to evade the immunity conferred by vaccines.
One study found the amount of virus shed from people infected with Delta to be over 1,000 times greater than from the original 2020 strain identified in Wuhan. Another study, which hasn’t yet been peer reviewed, showed Delta is more than twice as likely to cause hospitalisation, ICU admission and death.
So, the successful test and trace strategy of NSW, which controlled the Crossroads Hotel outbreak a year ago without needing a stringent lockdown, has not worked as well against Delta.
Delta makes the job so much harder
In the absence of enough vaccines for everyone, control of the epidemic requires:
- identifying all new cases by testing and isolating them to prevent further transmission
- tracing all contacts and quarantining them for the incubation period, so they don’t cause further transmission. SARS-CoV-2 is highly infectious in asymptomatic or pre-symptomatic people, so without contact tracing these people would carry on, unaware they are infected, and may infect many others. Retrospective contact tracing is also important to make sure you find from whom each person caught their infection
- masks to reduce inhaled virus for well people and also exhaled virus from infected people
- social distancing measures to reduce contact between people and thereby reduce transmission. Lockdown is the most extreme of these measures.
The struggle with the Sydney outbreak doesn’t mean contact tracing and testing are not working. In fact, until about July 16, measures were working — as reflected in an increasing “doubling time” (the time taken for case numbers to double). We want to see the time taken for case numbers to double increasing — that means spread is slowing.
However after the outbreak spread to Southwest Sydney, it began growing again, prompting an extended and stricter lockdown.
Contact tracing, quarantine of contacts and case finding by mass testing remain the cornerstones of epidemic control, especially when we remain largely unvaccinated.
But Delta makes the job so much harder.
One detailed study showed the average time from exposure to becoming infected was six days in 2020, but four days with Delta. This makes it harder to identify contacts before they’re infected.
NSW Health reports that when they start contact tracing, they are finding almost 100% of household members already infected, compared with about 30% last year. In South Australia it was reported people are getting infected and already infectious within 24 hours of exposure.
So what can we do other than lock down every time there’s an outbreak?
First, we need vaccines urgently. Only just under 12% of the population are fully vaccinated. The fact we’re largely unvaccinated leaves us vulnerable to severe outbreaks, especially with the more severe Delta variant. In countries like Israel, which has fully vaccinated over 60% of its population, although Delta is causing outbreaks, people are largely protected from hospitalisation and death.
We need to invest in more vaccine manufacturing capacity, including for mRNA vaccines, think ahead and start ordering booster vaccines to match variants such as Delta and another variant Epsilon now. If we don’t do this we could be experiencing “groundhog day” again next year, locked down and yet again waiting for vaccines.
Meanwhile, we cannot give up and let Delta spread just because we yearn for our old lives. Delta sweeping the nation will not give us what we desire — it will bring the dark hand of the pandemic into our homes, causing illness and death in loved ones and much worse economic loss. In a largely unvaccinated population, this more deadly virus will be catastrophic.
We must hold the line, tighten hotel quarantine and protect the community.
For now the strategy pioneered by Victoria last year may help — tracing contacts of contacts to be one step ahead. If the time to becoming infected is too short to catch contacts before they are contagious, then this is a good strategy. NSW has started doing this, so hopefully this will make a difference in Sydney’s ongoing outbreak.
Lei Zhang, Monash University; Christopher Fairley, Monash University; Guihua Zhuang, Xi’an Jiaotong University, and Zhuoru Zou, Xi’an Jiaotong UniversityVictoria has entered a five-day lockdown to control its growing outbreak of the more infectious Delta variant.
Until midnight on Tuesday restrictions mean residents are only allowed to leave home for essential reasons, can only travel five kilometres away from home, and need to wear masks outside the home, among other measures.
We consider the lockdown essential and we strongly support this rapid action. However our modelling predicts a five-day lockdown may not be enough.
Instead we predict at least 30 days of restrictions will be needed before Victoria reaches three days without community transmission.
That’s if we take into account current and predicted case numbers, the fact we’re dealing with the more infectious Delta variant, and with current levels of vaccination.
The good news is Victoria is more likely to reach these three “donut days” sooner if vaccination rates pick up, even modestly.
How did we come up with these figures?
We built a mathematical model based on nine COVID-19 outbreaks across four Australian states (including Victoria) since the start of the pandemic. We posted details online as a pre-print. So our model has yet to be independently verified (peer reviewed).
Our model allows us to predict — given current case numbers, the particular variant in circulation and vaccination rates, among other variables — how long public health restrictions such as lockdowns need to last to achieve particular outcomes. Our model also allows us to predict how many cases an outbreak has at its peak.
Models are mathematical tools to predict the future, something of course no-one can do with 100% certainty.
However, our model differs from others because it considers the difference between mystery cases and cases linked to a known case.
It also comprehensively integrates the effects of various public health measures, such as social distancing, wearing masks, contact tracing and vaccination.
What did we find about Victoria?
When we plug data about Victoria’s current outbreak into our model, this is what we find.
Our model predicts the number of daily reported cases of community transmission will continue to climb over the next week or so. Even with the current lockdown we predict a peak of at least 30 cases a day over the next 7-14 days.
We predict the current outbreak will last for at least 30-45 days before Victoria can return to three days of zero community transmission.
However, given the fact Delta is more transmissible than the original Wuhan version of the virus, controlling Victoria’s outbreak will inevitably be more difficult and take longer than dealing with an earlier outbreak of similar size.
New South Wales knows too well how hard it is to get a Delta outbreak under control, something our model predicted.
Back to Victoria, our model supports a hard lockdown that minimises the chance of ongoing transmission.
Strict lockdown (80% reduction in social activities) and mandatory mask use in public spaces and workplaces (90% coverage) — equivalent to what’s expected in Victoria’s current lockdown — have been effective in previous outbreaks in Victoria and other states.
However, we predict the same approaches may only have a 50:50 chance to contain the current Delta outbreak in Victoria.
This means the Delta variant is likely to linger, bouncing at a level of a dozen cases for weeks. This means public health authorities will find it hard to decide how and when to lift restrictions.
Please give me good news
Our model suggests even modest rises in the vaccination coverage in Victoria, by an additional 5% for example, would dramatically increase the chance of controlling the outbreak from 50% to over 80%. If an extra 10% were vaccinated the chance of controlling the outbreak is 94%.
This is because evidence is mounting vaccinated people are less likely to transmit the virus to others. That’s in addition to the vaccines’ well known benefits in reducing your chance of severe disease.
So getting as many Victorians vaccinated as quickly as possible is critical.
What do we make of all this?
Our study conveys a simple message. The battle against the Delta variant in the latest outbreak in Victoria will likely be tough but going early has given us the best chance.
This lockdown will not be as effective as earlier ones in Victoria and coming out of this will need to be carefully managed.
So keeping to the health advice, and vaccinating more Victorians as soon as possible even over the next few weeks, are key to handling this outbreak.
Lei Zhang, Associate Professor of Public Health, Monash University; Christopher Fairley, Professor of Public Health, Monash University; Guihua Zhuang, Professor, Xi’an Jiaotong University, and Zhuoru Zou, Doctor, Xi’an Jiaotong University
Margie Danchin, Murdoch Children’s Research Institute; Archana Koirala, University of Sydney; Fiona Russell, The University of Melbourne, and Philip Britton, University of SydneyThe Delta variant is surging across the globe, and the World Health Organization warns it will rapidly become the world’s dominant strain of COVID-19.
Delta is more infectious than the Alpha variant, and preliminary data suggest children and adolescents are at greater risk of becoming infected with this variant, and transmitting it.
Is this true? And with Sydney school students set to begin term 3 remotely, what’s the best way to manage school outbreaks?
Let’s take a look at the evidence.
Delta in children and young people
In the United Kingdom, where the Delta variant has been predominating since May, infections are rising fastest among 17-29-year-olds, who are mostly unvaccinated. Infections are also increasing in younger age groups, but at a lower rate.
Overall, increased transmission among children and young people may partly be due to Delta. But also, in countries like the UK, these age groups are most susceptible to infection because older groups have been largely vaccinated.
While we don’t yet have data on the severity of illness in children associated with the Delta variant specifically, we know with COVID generally, kids are much less likely to become very unwell.
Research from the Murdoch Children’s Research Institute found children clear the virus more quickly than adults, which might go some way to explaining this.
How is Delta affecting transmission in schools?
In 2020, face-to-face learning wasn’t a significant contributor to community transmission in Victoria. Similarly, during the first wave in New South Wales, transmission rates were low in education settings. Concerns children may bring infections home to vulnerable family members weren’t supported by the evidence.
However, the situation is looking somewhat different now with the emergence of new variants and varying levels of vaccine coverage in different countries.
There does appear to be more transmission in schools. In the week ending June 27 there were outbreaks in 11 nursery schools, 78 primary schools, 112 secondary schools and 18 special needs schools in the UK.
While outbreaks in schools are increasing, the vast majority of transmission still occurs in households.
In 2021 in Australia, there have been very few school infections with Delta. In Western Australia, where schools have remained open, an infectious case attended three schools but this didn’t result in any school outbreaks.
During the current NSW outbreak, there have been several schools and early childhood centres with COVID-19 cases, and we have seen one outbreak at a primary school.
Although schools in Australia have largely been spared, transmission rates have been higher than we’ve seen with other variants. Almost all household contacts of cases are becoming infected.
Fortunately, testing, tracing and isolating were very effective in containing the outbreak, even with the Delta variant.
But these recent school outbreaks highlight why it’s so important adults of all ages, especially parents and teachers, get vaccinated.
Should we vaccinate children?
There are benefits of vaccinating children, particularly teenagers. These include direct protection against the disease, but also reducing transmission to vulnerable adults and enabling continued school attendance.
The risks and benefits need to be carefully calculated in a low transmission setting like Australia. In terms of risks, emerging data suggest the mRNA vaccines Pfizer and Moderna are associated with a very small risk of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the heart lining) in young adolescents and adults, particularly males. Although most cases are mild, it can be a serious condition and is being closely monitored.
The United States, Canada, and a few countries in Europe are already vaccinating children over 12. Australia’s drug regulator is currently weighing this up.
For now, we should continue to vaccinate adults in priority groups. We have a long way to go to get the most vulnerable vaccinated first, and are still constrained by vaccine supply.
As we grapple with the benefits and risks for teenagers, it’s also worth asking them if they want to be vaccinated and why. Many have been adversely impacted by the pandemic and are desperate to move on with their lives.
What should parents look out for?
With the Delta variant, a headache, sore throat and runny nose are now the most commonly reported symptoms among unvaccinated people.
These symptoms have eclipsed fever and cough, the most common symptoms earlier in the pandemic.
So it’s imperative parents still take their children to be tested if they become unwell, even if the symptoms appear more like the common cold.
Where to from here?
When adults are more widely vaccinated and our borders open, school outbreaks will likely continue to happen. Even in places like Israel, where a high proportion of the population has received two doses, school outbreaks have recently occurred.
Australia needs a clear plan that outlines how best to keep schools open, while preventing transmission and keeping children and teachers safe during any outbreaks.
This should include school staff being prioritised for vaccination.
And until we have high vaccination coverage, there’s evidence that well implemented school-based mitigation measures work to prevent transmission in education settings.
This could include a range of measures, adjusted according to risk, such as keeping non-essential adults off school grounds, mask use in high school students (and possibly primary students too), staggering timetables, reducing class sizes and improving classroom ventilation.
By monitoring the effects of new variants on children’s health, coupled with detailed risk-benefit analyses, we will determine the best time for children and adolescents to be vaccinated.
In the meantime, parents and all eligible adults can do their bit to protect children and reduce the risk of school outbreaks by getting vaccinated themselves.
Margie Danchin, Paediatrician at the Royal Childrens Hospital and Associate Professor and Clinician Scientist, University of Melbourne and MCRI, Murdoch Children’s Research Institute; Archana Koirala, Paediatrician and Infectious Diseases Specialist, University of Sydney; Fiona Russell, Senior Principal Research Fellow; paediatrician; infectious diseases epidemiologist; vaccinologist, The University of Melbourne, and Philip Britton, Senior lecturer, Child and Adolescent Health, University of Sydney
With the World Health Organization (WHO) warning Delta will rapidly become the dominant strain, let’s take a look at this variant in a global context.
The rise and rise of Delta
The Delta variant (B.1.617.2) emerged quietly in the Indian state of Maharashtra in October 2020. It barely caused a ripple at a time when India was reporting around 40,000 to 80,000 cases a day, most being the Alpha variant (B.1.1.7) first found in the United Kingdom.
That changed in April when India experienced a massive wave of infections peaking at close to 400,000 daily cases in mid-May. The Delta variant rapidly emerged as the dominant strain in India.
The WHO designated Delta as a variant of concern on May 11, making it the fourth such variant.
The Delta variant rapidly spread around the world and has been identified in at least 98 countries to date. It’s now the dominant strain in countries as diverse as the UK, Russia, Indonesia, Vietnam, Australia and Fiji. And it’s on the rise.
In the United States, Delta made up one in five COVID cases in the two weeks up to June 19, compared to just 2.8% in the two weeks up to May 22.
Meanwhile, the most recent Public Health England weekly update reported an increase of 35,204 Delta cases since the previous week. More than 90% of sequenced cases were the Delta variant.
In just two months, Delta has replaced Alpha as the dominant strain of SARS-CoV-2 in the UK. The increase is primarily in younger age groups, a large proportion of whom are unvaccinated.
2 key mutations
Scientists have identified more than 20 mutations in the Delta variant, but two may be crucial in helping it transmit more effectively than earlier strains. This is why early reports from India called it a “double mutant”.
The first is the L452R mutation, which is also found in the Epsilon variant, designated by the WHO as a variant of interest. This mutation increases the spike protein’s ability to bind to human cells, thereby increasing its infectiousness.
Preliminary studies also suggest this mutation may aid the virus in evading the neutralising antibodies produced by both vaccines and previous infection.
The second is a novel T478K mutation. This mutation is located in the region of the SARS-CoV-2 spike protein which interacts with the human ACE2 receptor, which facilitates viral entry into lung cells.
One good thing about the Delta variant is the fact researchers can rapidly track it because its genome contains a marker the previously dominant Alpha variant lacks.
This marker — known as the “S gene target” — can be seen in the results of PCR tests used to detect COVID-19. So researchers can use positive S-target hits as a proxy to quickly map the spread of Delta, without needing to sequence samples fully.
Why is Delta a worry?
The most feared consequences of any variant of concern relate to infectiousness, severity of disease, and immunity conferred by previous infection and vaccines.
WHO estimates Delta is 55% more transmissible than the Alpha variant, which was itself around 50% more transmissible than the original Wuhan virus.
That translates to Delta’s effective reproductive rate (the number of people on average a person with the virus will infect, in the absence of controls such as vaccination) being five or higher. This compares to two to three for the original strain.
There has been some speculation the Delta variant reduces the so-called “serial interval”; the period of time between an index case being infected and their household contacts testing positive. However, in a pre-print study (a study which hasn’t yet been peer-reviewed), researchers in Singapore found the serial interval of household transmission was no shorter for Delta than for previous strains.
One study from Scotland, where the Delta variant is predominating, found Delta cases led to 85% higher hospital admissions than other strains. Most of these cases, however, were unvaccinated.
The same study found two doses of Pfizer offered 92% protection against symptomatic infection for Alpha and 79% for Delta. Protection from the AstraZeneca vaccine was substantial but reduced: 73% for Alpha versus 60% for Delta.
A study by Public Health England found a single dose of either vaccine was only 33% effective against symptomatic disease compared to 50% against the Alpha variant. So having a second dose is extremely important.
In a pre-print article, Moderna revealed their mRNA vaccine protected against Delta infection, although the antibody response was reduced compared to the original strain. This may affect how long immunity lasts.
A global challenge to controlling the pandemic
The Delta variant is more transmissible, probably causes more severe disease, and current vaccines don’t work as well against it.
WHO warns low-income countries are most vulnerable to Delta as their vaccination rates are so low. New cases in Africa increased by 33% over the week to June 29, with COVID-19 deaths jumping 42%.
There has never been a time when accelerating the vaccine rollout across the world has been as urgent as it is now.
WHO chief Tedros Adhanom Gebreyesus has warned that in addition to vaccination, public health measures such as strong surveillance, isolation and clinical care remain key. Further, tackling the Delta variant will require continued mask use, physical distancing and keeping indoor areas well ventilated.
The Indian health ministry classifies a variant as one of concern as soon as there’s evidence for increased transmission.
The new variant, known as “Delta plus”, AY.1 or B.1.617.2.1, has an extra mutation in the spike protein of the SARS-CoV-2 virus, the virus that causes COVID-19.
This mutation was found in samples from 48 people infected with the Delta variant in India, out of more than 45,000 samples.
So how is this variant different, and can it escape vaccine protection?
Remind me, what’s the Delta variant?
The more infectious Delta variant of the coronavirus has spread across the globe and is on track to become the world’s dominant strain, according to the World Health Organization.
The variant has been the dominant strain that led to the crippling second wave in India.
Studies have found it can replicate faster, spread more easily, and bind more strongly to lung cell receptors.
Also, in a pre-print study yet to be peer-reviewed, Delhi researchers found the variant caused three-quarters of “breakthrough infections” in the city. These are infections in people who’ve been vaccinated. Around 8% of these breakthrough infections had the Kappa variant, and 76% had the Delta variant.
How is the ‘plus’ variant different?
The new mutation in the Delta variant was first detected in Europe in March.
In June, COVID patients in India were also found to have the mutant virus. These developments have raised concerns.
Some scientists in India fear the mutation may fuel another wave of infections in the country.
The mutation in the spike protein of the virus, however, is not new. Known as “K417N”, it has been previously reported in the Beta variant first found in South Africa. The Beta variant with this mutation has shown an ability to escape the antibodies conferred by COVID vaccination, at least to some extent. In other words, there’s the possibility COVID vaccines will not protect against this mutation so effectively.
Will vaccines work against Delta plus?
The mutation is worrying because it’s located on a key portion of the virus, the spike protein, used to penetrate human cells.
Previous mutations have been on the “receptor binding domain” of the spike protein that allows the virus to attach to the receptors in our cells.
The unique mutations in the Delta variant mean the virus can escape the immune system to some extent. Indeed, Delta has shown to reduce efficacy of vaccines somewhat. This means a single dose of vaccine may offer reduced protection.
However, a second dose has been shown to produce enough antibodies against symptomatic infection and severe disease. It’s important to remember most COVID vaccines don’t provide absolute sterilising immunity, but work to reduce the severity of disease.
UK researchers found the Pfizer vaccine had an efficacy of 33% against Delta after a single shot, and 88% after both doses. In the case of the AstraZeneca vaccine, the efficacy was just 33% after the first dose but went up to 60% after the second dose.
The Delta plus variant might have a similar degree of reduction in efficacy against the vaccines currently in use. Though we’re yet see good data on whether this is the case.
Studies are under way in India to assess the effectiveness of vaccines against Delta plus.
It’s important to note Delta plus hasn’t yet taken off substantially, and the World Health Organization hasn’t yet classified it as a variant of concern.
What do we need to do now?
Variants with increased transmissibility and the potential to escape antibodies pose a threat to efforts to control and mitigate the pandemic. And countries with low vaccination rates may see new outbreaks.
How should our response change? Despite the mutations, no extra special measures need to be taken. We must continue to get maximum numbers of people vaccinated, increase genomic surveillance to track the evolution of the virus, and follow COVID-appropriate behaviour.