A Pfizer study released Wednesday determined that the mutations in the COVID-19 variants originally found in the United Kingdom and South Africa have “small effects” on the effectiveness of the company’s vaccine developed with BioNTech.
The preliminary research, conducted by Pfizer and University of Texas Medical Branch scientists, concluded that the results showed no need for an additional vaccine for the variants.
“While these findings do not indicate the need for a new vaccine to address the emerging variants, the Companies are prepared to respond if a variant of SARS-CoV-2 demonstrates evidence of escaping immunity by the COVID-19 vaccine,” Pfizer and BioNTech said in a release.
The study said the vaccine was slightly less effective on mutations for the variant first found in South Africa compared to other mutations.
“The Companies believe 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 companies said.
The study was published on preprint server bioRxiv, which publishes research before it is peer-reviewed, as more contagious COVID-19 strains have emerged and sparked worries that the current vaccines will not work against them.
This early study did not test the vaccine on the variants themselves but instead on a set of mutations found within the new strains.
Scientists used sera from 20 participants immunized during the third phase trial for the vaccine. Researchers did not determine if the results were statistically significant.
The Pfizer research aligns with early studies previously conducted with the company, including one that concluded the vaccine likely works against mutations in the strain from the U.K. Another study from earlier this month suggested the Pfizer-BioNTech vaccine would be effective against a key mutation found in the U.K. and South African strains.
The Pfizer-BioNTech was the first to be approved for use in the U.S., U.K. and European Union last month. The U.S. has also assigned emergency use authorization to the Moderna vaccine, which like the Pfizer-BioNTech shot requires two doses.
The U.S. has administered almost 25 million doses of the COVID-19 vaccine, with 3.8 million receiving both doses, according to data from the Centers for Disease Control and Prevention.