Current COVID vaccines could be ineffective by next year: epidemiologists

Two-thirds of epidemiologists who took part in a recent global survey have predicted it will be less than a year before SARS-CoV-2 mutates to such an extent that the majority of first generation COVID vaccines are rendered ineffective and new or modified candidates are required.
 
Commissioned by The People’s Vaccine Alliance, it also revealed that the overwhelming majority of the 77 epidemiologists surveyed (88%) believe that persistent low-vaccine coverage in many countries will make it more likely for vaccine-resistant mutations to appear.
 
Variants of concern have already emerged in South Africa, the US, India and Brazil, and Yale University’s Associate Professor Gregg Gonsalves said the fact that millions of people around the world are still contracting the disease means new mutations will arise every day.
 
‘Sometimes they find a niche that makes them more fit than their predecessors. These lucky variants could transmit more efficiently and potentially evade immune responses to previous strains,’ he said.
 
‘Unless we vaccinate the world, we leave the playing field open to more and more mutations, which could churn out variants that could evade our current vaccines and require booster shots to deal with them.’
 
Professor Dale Godfrey, Immunology Theme Leader at the Doherty Institute, told newsGP while ‘we can only guess’ how the situation will evolve, scientists and vaccine makers are preparing.
 
‘It is clear that variants are emerging that appear to exhibit greater resistance to at least some of the vaccines, at least in laboratory settings. How great of a risk this poses is unclear at the moment, because there is not enough information about how vaccine recipients respond to the variants that are emerging,’ he said.
 
‘There is some concern that the AstraZeneca vaccine shows much less protection against the South African strain [B.1.351], but it was quite a small study that did not examine whether there was still protection against severe disease.
 
‘It is entirely possible that most or all of the vaccines will still prevent severe disease and death, even if they are less effective at preventing earlier stages of disease. I think this is likely, but only time and further studies will tell.’
 
At least one real-world study is underway in Brazil which may provide some answers. Every adult in Serrana, a town of 45,000 people in the hard-hit state of São Paulo, has received at least one dose of the Chinese-developed CoronaVac in an effort to track the impact vaccination has against the disease.
 
Aside from testing to see how effective vaccines are at reducing transmission and serious cases, the highly contagious P.1 variant – which led to a number of cases of reinfection in the Amazonian city of Manaus – has become the dominant strain in Brazil, so the study may also help indicate how much impact it could have on vaccine efficacy.
 
Infectious diseases physician and microbiologist Associate Professor Paul Griffin told newsGP emerging COVID variants are ‘likely’ to have some impact on the efficacy of currently used vaccines.
 
‘The natural industry of all living organisms is that they will evolve … so I think the emergence of an escape variant at some point in time is a fairly probable event,’ he said.
 
‘But the main point there is while the efficacy of the majority of current vaccines will likely be reduced, there are a lot of so-called “second generation vaccines” coming through that will be less susceptible to reduced efficacy from new variants.
 
‘Our ability to make a new vaccine that addresses an escaped variant [has also improved] ... there’s a fairly clear path for testing vaccines for those variants, so getting it from needing to be developed to being rolled out will be a relatively quick process in the order of weeks, to a small number of months.
 
‘So while I think it’s an event that is likely to happen, it’s an event that we can manage well.’

Brazil has been hit hard by coronavirus and there are fears emerging variants of concern could spill over into other countries.
 
Professor Godfrey is also relatively confident that vaccine developers will be able to combat any new variants that emerge.
 
‘Vaccine manufacturers are already developing and testing new versions of their vaccines that are better matched to the variants. This is similar to how we have to keep up with influenza variants that emerge each year,’ he said.
 
‘It is possible that a regular booster for coronavirus will be required. With all the great progress that has been made in the past year with coronavirus vaccines, scientists and pharma should be able to keep up in this race.
 
‘A key consideration will be whether the vaccines maintain protection against severe disease, even if they are less effective at preventing early stages of infection. If so, I think most people will feel far less vulnerable if the risk of infection amounts to little more than cold-like symptoms.’
 
Should a variant of concern emerge prior to the development of an effective vaccine, Professor Godfrey believes Australia is well placed to mitigate its spread – for now.
 
‘In one sense, Australia has proven ability to contain and even eliminate the virus for extended periods. If we maintain our approach to handling outbreaks this should also apply to the variants,’ he said.
 
‘[But] if these variants do become increasingly capable of escaping from vaccine-induced immunity then we may be in the same boat as other countries. Keeping the virus out and containing it whenever it escapes is still critical and will be for some time, regardless of whether it is a variant or the original ancestral strain.
 
‘In the meantime, Australia should continue to focus on rolling out whatever vaccine we have, which for most people will be the AstraZeneca vaccine.’
 
According to Professor Griffin, adopting such an approach worldwide will be important for protecting Australia against any future variants that have the potential to be more damaging than the current strains.
 
‘The main thing is trying to get on top of this globally as quickly as possible … every case we prevent now is reducing the probability of those mutations arising that will lead to an escape variant,’ he said.
 
‘It’s up to all of us to try and reduce the numbers in total that we get.’
 
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