As part of our #FactOfTheMatter series, The Canary explores whether emerging mutations of coronavirus (Covid-19) will lead to people in the UK needing to be re-vaccinated. With emerging strains being reported in South Africa and Brazil, the question for experts is will people need to be re-vaccinated because of coronavirus variants? Here is what we know so far.
On 6 January, an emerging strain was found from Brazil, making it the latest variant to be reported after South Africa, the UK and Denmark.
Covid-19 emerging strains timeline
The current coronavirus timeline of emerging strains is listed below, accurate at the time of publication.
- 6 January 2021- Mutation– Brazil
- 18 December 2020- South Africa announced the detection of a new variant of SARS-CoV-2 that is rapidly spreading in three provinces of South Africa.
- 14 December 2020- The United Kingdom reported to WHO a variant referred to by the United Kingdom as SARS-CoV-2 VOC 202012/01
- August and September 2020- Denmark identified a SARS-CoV-2 variant linked to infection among farmed mink.
With new strains being found, and the UK- Kent variation being dubbed a ‘variant of concern’ by scientists, it raises an important question: will we have to be re-vaccinated because of mutations?
Will current vaccines still work?
Speaking about the emerging strains in Brazil, Oxford vaccine clinical trials, Lead, Andrew Pollard told The British Medical Journal (BMJ):
In those settings, variants of the virus that emerge that are able to spread despite existing post-infection immunity will be selected. If that’s the case, it doesn’t necessarily mean that we’re going to find ourselves in a position where vaccines don’t work against hospitalisation or severe disease, but it may be more difficult to prevent milder disease and transmission.
We need to monitor the situation carefully and work out the process that would be needed to make an adjusted vaccine, should the need arise.
While the three main vaccines: Pfizer BioNTech, Moderna, and Oxford AstraZeneca were all designed in a slightly different way, they all do the same thing which is to reduce the effect of coronavirus. Although all slightly different, they target what is called a ‘spike protein‘ of the virus.
Imperial College London, Department of Infectious Disease, Dr John Tregoning explained to The Canary why we are seeing Covid-19 mutations:
Selection pressure is a term that comes from evolution. All living things are under some level of evolutionary pressure – the fittest ones will produce more offspring. Selection pressures are the external factors that restrict the ability of an organism to replicate. Covid-19 is caused by a virus (SARS-CoV-2) and because it needs to replicate it is under selective pressures. This occurs at an accelerated rate to more complex organisms because viruses replicate very quickly and to very high numbers.
How does selective pressure affect Covid-19?
Tregoning explained that selective pressure is not just one thing but several things that can affect a virus:
There are a number of selective pressures but two of the main ones for viruses are how quickly they can spread and how easily they are seen and destroyed by the immune system. When nobody has seen the virus before, the speed and ease with which it can infect people is the main factor.
One question we had was: what happens when the pressure on the virus gets bigger?
Tregoning told The Canary:
Over time as more people have been infected the immune system becomes a bigger pressure on the virus. The most important feature of the immune response in this context is immune memory – previous infection with a virus will give you protection against future infection with the same virus. So only ones that cannot be recognised by the immune system will spread. Of course this is not completely black and white, there will be some viruses that are partially infectious or some people who are more susceptible.
However, this doesn’t mean that experts can predict if and when mutations occur.
Experts can’t predict whether Covid-19 will mutate again
Speaking to the British Medical Journal (BMJ), Pollard explained why mutations are happening:
When lots of people have had disease or been vaccinated, the virus is going to come under a lot of pressure, and when that happens some viruses just can’t compete against that immunity.
Will it mutate instead? With this coronavirus we don’t know the answer to that question yet, and that’s why surveillance is going to be critical in the year ahead to make sure that we’re not in a position where, at the point of population immunity, the virus escapes. And if it does, we need to know that, so that we can redesign the vaccines.
However Imperial College London, Department of Infectious Disease, Dr John Tregoning told The Canary that mutations may help scientists in the long run:
The immune pressure is mostly coming from previous infections – most of the new variants arose before the vaccines were introduced or in countries where there has been no vaccine rollout. One interesting feature of the mutations that have arose is that they all fall within very similar places on the spike protein (the one the virus uses to get into cells). This may help scientists design vaccines to target the new variants or understand how it might change over time, but it is too early to say.
However, according to those that have investigated the virus, it’s not a case of whether we will see future mutations, but rather, preparing for a life with Covid-19.
Professor Ferguson, an epidemiologist at Imperial College London, has stated that we may never eliminate coronavirus, but that international focus must be on monitoring and updating our medicine to deal with it:
Looking forward we’re going to be living with coronavirus indefinitely, we’re never going to eliminate it from the human population, it will evolve, and we may need to regularly update our vaccines.
But how easy is it to update vaccines?
Vaccines could be tweaked for ‘2021 booster campaigns’
While the vaccine can be tweaked, Pollard suggests that changes to the science would be an easier step than the manufacturing and logistic operation a new vaccine would need.
Pollard explained to the BMJ:
For the RNA vaccines and the viral vectors it’s relatively straightforward, because you just have to synthesise a new bit of DNA in our case—or RNA in [the Pfizer and Moderna] cases—and then insert that into the new vaccine. Then there’s a bit of work to do to manufacture the new vaccine, which is a reasonably heavy lift. But the same processes would be used.
The second component is that there will almost certainly need to be some testing, whether it’s in animals or humans, to show that you can still generate immune responses, and then the regulator would have to approve that new product.
Meanwhile Imperial College London, Department of Infectious Disease, Dr John Tregoning told us that we could see new vaccines in upcoming booster campaigns later this year:
One of the impacts of the mutations is potentially reduced efficacy of the first generation of vaccines. It is important to stress that these are currently highly effective and no severe disease has been reported in the vaccinated arm of any of the trials, so it is definitely worth being immunised as this will help to reduce the burden of infection globally, also reducing the likelihood of further mutation. But as a precaution, second generation vaccines that target the new variants are being developed – it is possible these will be used in an autumn booster campaign later in 2021.
The Canary contacted the Department for Health and Social Care, NHS England and the Oxford Vaccine Group about the impact new vaccines could have on manufacturing, logistics and distribution to the general public. They were unable to comment at the time of publication.
Close monitoring is vital
One of the teams monitoring mutations is The G2P-UK National Virology Consortium.
The Consortium work with The COVID-19 Genomics UK (COG-UK) to study how mutations may affect transmission, vaccines and treatments.
By carrying out rapid whole genome sequencing they aim to help monitor new variants. The consortium then shares data with other organisations such as the GISAID: as it tracks the coronavirus pandemic in real-time.
G2P-UK co-lead, Michael Malim explained in a recent webinar that because of the work the consortium is doing, they would know ‘pretty quickly’ whether a new strain would be a risk to those who are vaccinated:
Once a sequence of interest is identified we’ll be able to synthesise that spike gene and make virus particles in the laboratory. Then we’ll test the sensitivity of that virus to inhibition of infection in laboratory models to a range of sera from vaccines and natural infection, and work out if there is a change. It would take about two to three weeks from knowing which sequence to focus on to having those results. So, pretty quickly, we would know where the variant, for example, could potentially break through vaccination.
A global task-force is ready
A global surveillance system is something that the World Health Organization has been working on.
The WHO’s SARS-CoV-2 global laboratory network has been monitoring virus mutations since it was formed in June 2020.
The working groups who have expertise in sequencing are currently working with other countries to see how current monitoring can be improved.
Addressing new variants the WHO stated:
While mutations of SARS-CoV-2 are expected, it is important to continue to monitor the public health implications of new virus variants. Any increased in transmissibility associated with SARS-CoV-2 variants could make control more difficult. Current disease control measures recommended by WHO continue to be effective and should be adapted in response to increasing disease incidence, whether associated with a new variant or not.
The group will continue to work on finding ways that systems can be strengthened or adapted to better monitor variations and aid international centres in the fight against coronavirus. While the logistics and manufacturing of a new vaccine is a large task, it seems scientists are confident in their ability to modify existing vaccines if needed. While scientists are confident in their ability to supply changed vaccines, little is known about what manufacturing and logistical issues this might cause the Department for Health and Social Care and Public Health England in distributing vaccines.
Featured Image: RF._.Studio
