COVID-19 vaccines developed by Pfizer and Moderna appear to provide significantly less protection against antibodies to the highly contagious variant in South Africa, new studies show.
The studies, published Wednesday in the New England Journal of Medicine, indicated that both vaccines generated much lower levels of neutralizing antibodies against the new strain compared to the original SARS-CoV-2 virus.
For the Pfizer study, the scientists developed a projected virus that contained the same mutations carried on the top portion of the South African variant, known as B.1.351.
The researchers tested the virus projected against blood taken from people who were given the vaccine.
They found that there was a two-thirds reduction in the level of neutralizing antibodies compared to how it worked with the most widespread version of the virus in US studies.
However, it is unclear whether the reduced antibody response will make the vaccine ineffective against the strain, as it is not known what level is needed to neutralize the virus.
“We do not know what the minimum neutralization number is. We don’t have this cutting line, “said study co-author Pei-Yong Shi.
Meanwhile, the Moderna study found a six-fold decrease in the antibody response against the variant in its vaccine.
The results were published as part of a letter from the Massachusetts company in the same journal.
But researchers have similarly warned that the effectiveness of the Moderna vaccine against the strain is not yet known.
The company previously said it believes the vaccine will provide protection against the variant.
Currently, there are 19 cases reported by B.1.351 in the United States in 10 states, according to the Centers for Disease Control and Prevention.
With Post threads