A laboratory study suggests that the South African variant of the coronavirus may reduce antibody protection from the Pfizer Inc/BioNTech SE vaccine by two-thirds, and it is not clear if the shot will be effective against the mutation, the companies said on Wednesday, according to Reuters.
The study found the vaccine was still able to neutralize the virus and there is not yet evidence from trials in people that the variant reduces vaccine protection, the companies said.
For the study, scientists from the companies and the University of Texas Medical Branch (UTMB) developed an engineered virus that contained the same mutations carried on the spike portion of the highly contagious coronavirus variant first discovered in South Africa, known as B.1.351.
The spike, used by the virus to enter human cells, is the primary target of many COVID-19 vaccines.
Researchers tested the engineered virus against blood taken from people who had been given the vaccine, and found a two- thirds reduction in the level of neutralizing antibodies compared with its effect on the most common version of the virus prevalent in US trials.
The findings were published in the New England Journal of Medicine.
UTMB professor and study co-author Pei-Yong Shi said he believes the Pfizer vaccine will likely be protective against the variant.
Even if the concerning variant significantly reduces effectiveness, the vaccine should still help protect against severe disease and death, he noted, according to Reuters.
Pfizer and BioNTech said they were doing similar lab work to understand whether their vaccine is effective against another variant first found in Brazil.