May 16, 2024
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More preliminary results in the lab suggest the Pfizer/BioNTech coronavirus vaccine will be effective against new, more contagious coronavirus strains first identified in South Africa and the UK. 

As in previous studies, antibodies were slightly less effective against the virus with three key mutations in the variant identified in South Africa. However, Pfizer and BioNTech said, “the small differences in viral neutralization observed in these studies are unlikely to lead to a significant reduction in the effectiveness of the vaccine.”

The researchers engineered versions of the virus in the lab that carry some of the mutations found in the variants. They tested them against blood taken from 20 people who had received two doses of the Pfizer/BioNTech vaccine as part of a clinical trial.  

The lab study – conducted by researchers at Pfizer and the University of Texas Medical Branch – did not test all the mutations found in the variants, and researchers note that “clinical data are needed for firm conclusions about vaccine effectiveness against variant viruses.” 

The results were posted Wednesday on the preprint server bioRxiv and have not yet been peer-reviewed or published in a medical journal. 

Pfizer and BioNTech said Wednesday a new vaccine against the variants does not appear to be necessary. In a news release, they said they will continue to monitor strains and will conduct studies to monitor how effective the vaccine is in the real world. Pfizer said earlier this week it was “laying the groundwork” to create a vaccine booster that could respond to coronavirus variants, if necessary.

Moderna, the maker of the other coronavirus vaccine authorized in the United States, said this week its Covid-19 vaccine created antibodies that neutralized the coronavirus variants first found in the United Kingdom and South Africa, and it planned to test a booster against the variants “out of an abundance of caution.”