Those variants both share a common mutation called N501Y, a slight alteration on one spot of the spike protein that coats the virus.
The spike protein is the target of many of the COVID-19 vaccines that have been developed including candidates from Pfizer-BioNTech, Moderna and the University of Oxford-AstraZeneca. As such, worries that the variants may be able to evade vaccine-induced immunity have recently surfaced.
A study, which was sponsored by Pfizer-BioNTech and has yet to be peer-reviewed, looked at a small sample size of 20 people who had been vaccinated with the Pfizer-BioNTech vaccine. The research demonstrated that blood samples from these individuals were able to successfully neutralize viruses carrying the N501Y mutation.
Findings are 'positive'
Dr Adam Barker, healthcare analyst, Shore Capital, in a note this morning on the research, said the study is positive given it is some of the first evidence to demonstrate that Pfizer/BioNTech’s vaccine can be effective against relevant mutations.
“However, it doesn’t conclusively tell us whether the vaccine will work against the specific constellation of mutations found in VUI202012-01 [the variant seen in the UK]. That being said, the working assumption remains that vaccines will be (at least partly) effective against the novel variants given the heterogeneous immune response that they induce.”
Delving further into that paper, he said as it was an in-vitro study, it does not indicate whether the vaccine actually prevents people being infected with the new variant.
A large study would be needed for that, said the analyst.
“But secondly, and most importantly, this study merely demonstrates that a virus carrying the N501Y mutation can be as effectively neutralized compared to wild-type virus.
“However, VUI202012-01 has several novel mutations and will likely have different structural properties compared to viruses solely carrying N501Y. Indeed, to take one example, the 69/70 deletion that it carries has been previously shown to be associated with escape from the immune system. Perhaps that is the important mutation when it comes to worries over vaccine effectiveness?
“But, overall, the key point is knowing whether vaccine-induced immune responses can neutralize VUI202012-01 (and all of its associated mutations) in its entirety. Not just whether the vaccine-induced immunity can handle one of the mutations (as this study addresses). We believe further studies to address this question are underway,” commented Dr Barker.
Mutations in UK variant
The Shore Capital analysts outlined how the UK COVID-19 virus variant, VUI202012-01, has several key mutations, including:
• N501Y – One of the key residues in the receptor binding domain (RBD) that the virus uses to enter human cells. Some studies have shown that this mutation enhances the binding ability of the virus in human and mouse cells.
• P681H – Next to a part of the virus called the “furin cleavage site”. This site is not found in closely related coronaviruses and this mutation has been shown to promote transmission in animal models.
• 69/70 deletion – This deletion has occurred several times before alongside RBD mutations and was also found in the well-publicised mink mutants from Denmark.
All of these mutations have occurred independently around the world, but VUI202012-01 is unique in that it contains all of them, said the analysts.