Studies have shown that the Pfizer-BioNTech and Moderna COVID-19 vaccines could have reduced protection against the most contagious variant first discovered in South Africa, raising concerns about the effectiveness of the vaccines against the strain.
Reports for the New England Journal of Medicine indicated that the two vaccines currently available in the United States decreased the protection of antibodies when they increased against mutations found in the South African strain, Reuters reported. But both studies showed that the vaccines appeared to generate enough antibody response to neutralize the COVID-19 virus.
The studies used genetically modified types of the virus against blood samples from those who had already been vaccinated, reported The Washington Post.
The Pfizer study determined that by combating the South African variant, about a third of its antibodies were activated compared to combating the original strain.
For the Modern vaccine, the researchers found a six-fold decrease in the antibody response against the variant first found in South Africa, according to Reuters. But the study indicated that the efficacy of the Modern vaccine against the strain was not yet known.
It is not clear whether the reduced antibody response will render vaccines ineffective against strain B.1.351, as it is currently unknown what level of neutralization is needed to fight the virus.
Pfizer in a statement said the company was “taking the necessary steps … to develop and seek authorization” for an updated or booster vaccine to help people fight the South African variant.