By: NOLAN PAGE
Sept 21, 2020 a variant of coronavirus ( strain B.1.1.7) was first identified in the UK. This variant quickly gained infamy as being much more contagious than the original strain of coronavirus as it spread across the UK and beyond. It also brought to the attention of the public the issue of possible new variants of coronavirus. When inside an infected person, the coronavirus has the potential to mutate and change itself slightly. When many mutations occur at once (in the case of the UK strain, there were 23 individual mutations), this can create a new strain that is significantly different from the original. Though this strain has not shown itself to be any more deadly than the original strain, in light of the development of vaccines and discovery of another strain from South Africa, there are a variety of factors of this issue that must be addressed:
South African Strain
A new strain of COVID-19 has been spreading in South Africa since late last year, and has since been established to have been spreading in the US as at least two Maryland residents have been confirmed to have contracted the new strain without leaving their community. Our best defense against the presence of this strain in the US is still the social distancing, sanitary and masking guidelines, as Dr. Annabelle de St. Maurice who is co-chief officer of infection prevention at UCLA Health says, “…this doesn’t change necessarily what you do — it just reinforces the importance of doing these public health measures and following the guidance.” Similar to the UK strain, the South African strain has not been shown to be any more fatal than a typical strain of COVID-19, but it has been estimated to be up to 50% more contagious than the typical variety of COVID-19. This is due to the fact that these strains separately developed many of the same mutations that alter a part of the virus called the spike, which affect how easily the virus can enter a person’s cells.
However, unlike the initial UK variant, the South African strain has additional mutations that affect the protein spike. In addition to the mutation they share, called N501, the South African variant has a mutation called E484K which makes it resistant to antibodies. The E484K mutation has also since been found in some recent versions of the UK strain and is also found in a strain called P.2 discovered in Brazil.
Two prominent strains have been discovered in Brazil: P.1 and P.2. P.1 shares characteristics with the early UK strain, having increased contagiousness but not resistance to antibodies, but P.2 does have this E484K mutation as well. Though less is known about these strains, according to the Los Angeles Times, P2 has been seen to be able to reinfect those who have already had COVID-19 which may be due to the E484K mutation.
How this Affects Vaccines
The change in shape of the protein spike in the strains with the E484K mutation can cause resistance to immunity caused by antibodies that appear after having COVID-19 and after being vaccinated with some types of COVID-19 vaccines. The South African strain, which is the strain with E484K that has been studied most thoroughly, has shown to have some resistance to current COVID-19 vaccines, but the vaccines are still largely effective. In their current states, Pfizer and Moderna have both found that their vaccines are effective against the South African strain and keep antibodies at safe levels, but that they are working on modifying their vaccines to be more effective against this strain. Unapproved vaccines that are still in experimental phases seem to be faring worse, as a vaccine in development from Novavax falls from 89.3% successful at preventing an infection from a typical strain to 49.4% at stopping the South African strain.
New Covid Strains In the Future
Though the mutations that caused these new variants are atypical because of the stable nature of the coronavirus’ genome, there is concern for the possible appearance of new strains in the future. The more people that contract the virus, the more opportunity there is for mutations to occur. The US is currently ramping up its genome sequencing in an effort to ensure that if any new strains appear, they will be identified and studied quickly.
It is possible that vaccines may be less effective at preventing new strains of COVID-19, they still will be incredibly powerful tools in doing things like reducing severity of COVID-19 cases. As Dr. Bruce Y Lee of the City University of New York says, “It’s like how, even if a flu vaccine is 30 percent effective, we still recommend getting a flu shot.” The best way to reduce the likelihood of the appearance of new, possibly more dangerous strains is to minimize the amount of people infected with COVID-19, so please wear your mask and stay safe.