n a small-scale study, researchers from the Department of Biochemistry and Molecular Biology, University of Texas, US, have tested antibodies generated by 20 patients given the BNT162b2 (i.e., the Pfizer vaccine) against a laboratory-developed isogenic COVID-19 variant that contained mutations in the N501 and Y501 regions and which is similar to the South African variant. Sera were drawn 2 or 4 weeks after immunisation with two doses of the vaccine, spaced three weeks apart. The team used the plaque reduction neutralisation test to quantify the tire of neutralising antibody generated against COVID-19. This test is considered to be the best and most widely used approach to measuring virus-neutralising and protective antibodies generated in response to a virus.
Findings
The results showed that there were
equivalent neutralising titres generated in response to both the Y501 or
N501 spike mutations which means that the vaccine is most likely to be
effective. The authors noted a limitation of their findings was that the
Y501 mutant does not contain the full set of mutations found in either
the UK or South African variant. They concluded by calling for
continuous monitoring of the virus which could necessitate a change in
the vaccine strain.
