AS vaccinations continue to ramp up worldwide in the fight against COVID-19 amidst uncertainties over variants of concern, early data from a lab study shows that the mRNA COVID-19 vaccines from Pfizer and Moderna are effective against some of the variants.
The finding is contained in a study conducted by researchers from University of California and Gladstone Institute of Virology in San Francisco who assured that both Pfizer and Moderna vaccines elicited immune responses, particularly robust T cell responses, against UK B.1.117 and South African B.1.351 variants.
According to the findings, these vaccines are effective against the deadly variants such as the one that was first detected in India (B.1.617) and classified as a ”variant of concern” at the global level by World Health Organisation (WHO) as well as the UK B.1.117 and South African B.1.351 variants.
To come up with the finding, the researchers focused on the T cell response as key to long-lasting immunity where they established that the vaccines stimulated the generation of T cells specific the virus that causes COVID-19 against both B.1.117 and B.1351 in similar numbers and phenotypes.
Approving the results as another reassurance that vaccine-elicited T cells respond robustly to both the B.1.1.7 and B.1.351 variants, the study revealed that the second dose of either vaccine boosted the quantity but not the quality of the T cell response after the researchers examined vaccine-induced immunogenicity in individuals previously infected with COVID-19 (referred to as convalescents).
They also found that while one dose is beneficial in convalescents, a second dose does not improve T cell numbers, and thus offers no added value after the researchers first identified SARS-CoV-2-specific T cell populations in the 24 samples by measuring T cell responses to the spike proteins of the original strain of SARS-CoV-2 and B.1.117 and B.1.351 by exposing them to 15-mer peptides of the full-length spike protein from each strain in the samples.
Many analyst explain the report as back-up to a study conducted by Pfizer, BioNTech, and University of Texas which showed that Pfizer/BioNTech vaccine was effective against three variants including the P.1 Brazilian strain.
It will be recalled that Moderna had also released results of a Phase II study earlier this month that showed its new, slightly modified booster shot designed against B.1.351 provided additional protection against the original strain of the virus as well as the P.1. and B.1.351 variants.