- Over the past few months, rapidly spreading coronavirus strains have emerged in South Africa and the UK.
- On Thursday, Pfizer published a preliminary study suggesting its vaccine is effective against the new variants.
- In the study, researchers tested blood samples from 20 people who had already received the vaccine
Since the emergence of the new coronavirus variants in South Africa and the UK, people have raised concerns about the effectivity of approved vaccines against the strains. However, scientists have constantly denied any such claims. Now, a new preliminary study by Pfizer has found evidence of the vaccine being effective against the new coronavirus variants.
Although the new strains are different, they do share a common mutation called N501Y. This particular mutation is located on the receptor-binding site of the spike protein. Scientists believe the mutation allows the virus to bind more tightly to cells and thus increase the virus’s transmissibility. Therefore, Pfizer teamed up with researchers from the University of Texas Medical Branch (UTMB) to test their vaccine against the key mutation. They published their results on the preprint server bioRxiv.
Pfizer Vaccine Protects Against New Coronavirus Variants
The team of scientists collected blood samples from 20 participants who had received the Pfizer vaccine previously, as part of the vaccine trial. They then exposed the samples, in-vitro, to isogenic virus with the N501Y mutation. Next, they tested the samples for neutralizing antibodies against the mutation.
Findings showed that the Pfizer vaccine successfully neutralized the isogenic virus containing the mutation. Thus, proving that the Pfizer vaccine can work against the new coronavirus variants. Furthermore, the samples demonstrated neutralizing antibodies against 15 other mutations found in the new strains.
Dr. Philip Dormitzer, Pfizer’s chief scientific officer, described it as a ‘reassuring finding’.
What About Other Mutations?
Although the findings are encouraging, the study has a few limitations. Firstly, Pfizer did not test the other two vaccines – Moderna and Oxford – currently in use across the world. Secondly, the team did not look at all the mutations found in the new coronavirus variants.
E484K is a key mutation found in the South African variant of the novel coronavirus. It not only helps the virus attach more tightly to the cells, but also makes it resistant to antibodies. Therefore, the mutation has become a source of concern for scientists across the world. Although the Pfizer study tested for 15 additional mutations, it failed to test for E484K. However, the team says it plans to continue testing the vaccine’s efficacy against further mutations found in both the strains.
Despite the growing concerns, scientists believe that due to the mRNA technology used in Pfizer vaccine, any changes required can easily be done within 6 weeks.
Xie, Xuping, et al. Neutralization of N501Y Mutant SARS-CoV-2 by BNT162b2 Vaccine-Elicited Sera. 1 Jan. 2021, www.biorxiv.org/content/10.1101/2021.01.07.425740v1.