Pfizer vaccine only slightly less effective against key South African mutations – study

NEW YORK – Pfizer Inc and BioNTech’s COVID-19 vaccine appears to lose only a little efficacy against a modified virus with three key mutations in the new variant found in South Africa, according to a laboratory study conducted by the manufacturer American drugs.

The study by Pfizer and scientists at the University of Texas Medical Branch (UTMB), which has not yet been peer reviewed, showed less than twice a reduction in levels of antibody titre, indicating that the vaccine would probably still be effective in neutralizing a virus with the so-called E484K and N501Y mutations found in the South African variant.

The study was carried out on blood taken from people who had received the vaccine. Its results are limited, as it does not look at the full set of mutations found in the new South African variant.

According to Pei-Yong Shi, author of the study and professor at UTMB, scientists are currently designing a virus with the full set of mutations and expect to have results in about two weeks.

The results are more encouraging than another unpaired study conducted by scientists at Columbia University earlier Wednesday, which used a slightly different method and showed that the antibodies generated by the injections were significantly less effective against the South African variant.

One possible reason for the difference could be that Pfizer’s results are based on a modified coronavirus, and the Columbia study used a pseudovirus based on vesicular stomatitis virus, a different type of virus, said Shi of the ‘UTMB. He said he believed the pseudovirus discovery should be validated using the real virus.

The study also showed even better results against several key mutations in the highly transmissible British variant of the virus. Shi said they are also working on a virus designed with the full set of mutations in this variant.