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

NEW YORK (Reuters) – Pfizer Inc and BioNTech’s COVID-19 vaccine appeared to lose only a little bit of effectiveness against an engineered virus with three major mutations of the new coronavirus variant found in South Africa, according to a lab study conducted by the US. medicine maker.

The study by Pfizer and scientists at the University of Texas Medical Branch (UTMB), which has not yet been peer reviewed, showed a less than 2-fold reduction in antibody titre levels, indicating that the vaccine would likely be effective in neutralizing a virus. with the so-called E484K and N501Y mutations found in the South African variant.

The study here was conducted on blood taken from people who had received the vaccine. The findings are limited because it does not look at the full set of mutations found in the new South African variant.

While these findings do not indicate the need for a new vaccine to address the emerging variants, Pfizer and BioNTech are willing to respond if a variant of SARS-CoV-2 shows evidence escaping immunity through the COVID-19 vaccine, the companies said. .

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

The results are more encouraging than another non-peer-reviewed study by Columbia University scientists earlier on Wednesday, which used a slightly different method and showed that 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 findings are based on an engineered coronavirus, and the Columbia study used a pseudovirus based on the vesicular stomatitis virus, another type of virus, UTMB’s Shi said. He said he believes finds in pseudoviruses should be validated with the real virus.

The study also showed even better results against several key mutations of the highly transmissible British variant of the virus. Shi said they were also working on a manipulated virus with that variant’s full set of mutations.