- Pfizer-BioNTech and Moderna’s COVID-19 injections were at least 10 times less effective against a coronavirus variant in a new study.
- The researchers tested the variant vaccines found for the first time in South Africa, which is now in 20 U.S. states.
- A mutation in the variant called E484K appeared to be a “major contributor”, said the study’s authors.
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The COVID-19 vaccines from Moderna and Pfizer-BioNTech appear significantly less effective against the coronavirus variant first found in South Africa, a laboratory study suggested.
The percentage of protective antibodies that neutralized the variant – called B.1.351, which was recorded in 20 US states – was 12.4 times lower for COVID-19 from Moderna than against the original coronavirus and 10.3 times lower for o Pfizer, the study authors said.
This was a bigger drop than in previous laboratory studies that tested vaccines against manufactured forms of the variant, they said. For this study, the researchers used real forms of the variant taken from people who contracted the virus.
The Pfizer and Moderna vaccines have been authorized for emergency use in the United States.
B.1.351 was first detected in South Africa in October 2020. Since then, it has spread to 42 countries, including the United States, where it is circulating in at least 20 states, including California and Texas, the Control Center said. and Disease Prevention. There are 81 reported cases of B.1.351 in the US in general, said the CDC.
The researchers found that the antibody activity of both vaccines was “essentially unchanged” against the variant first found in the UK, B.1.1.7. There are 3,037 cases reported in the US from B.1.1.7, according to the CDC, and experts believe it will soon become the dominant strain in the USA.
The scientists at Columbia University also tested viruses made in the laboratory that had certain mutations. They said that a specific mutation, E484K, appeared to be a “major contributor” to variant B.1.351’s ability to prevent the antibody response. E484K is generally not present in B.1.1.7, the variant found for the first time in the United Kingdom.
The study was accepted by the scientific journal Nature, but has not yet been published.
Taking samples from the real world
In the experiment, the scientists collected 10 blood samples from people who received two doses of the Pfizer vaccine, 28 days after the second dose, and 12 samples from people who received two doses of the Modern vaccine, 43 days after the second dose. They then compared how well the antibodies in the blood samples “neutralized” the original coronavirus, compared to real-life coronavirus B.1.1.7 and B.1.351 variants.
The sample size was small and the antibody response is only one aspect of the immune response, so it is unclear how vaccines work against the variant first found in South Africa in real life.
Pfizer has conducted tests on petri dishes before, which showed a less potent antibody response against a lab-made variant of coronavirus that mimicked the variant first found in South Africa. It was not the exact B.1.351 variant.
Moderna performed similar tests and said that her vaccine resisted the mutations found in B.1.1.7, the variant found first in the UK, but less well against the mutations found in B.1.351, the variant first identified in South Africa. . Again, he used variants made in the laboratory.
Both companies said in January that they were developing booster shots specifically to combat variant B.1.351.
None of the vaccines have been properly tested against the variant first found in South Africa in the real world.
In Israel, the Pfizer vaccine has been shown to be highly effective against variant B.1.1.7, found for the first time in the United Kingdom. About 80% of Israelis with COVID-19 are infected with B.1.1.7.
Johnson & Johnson’s COVID-19 vaccine was less effective in clinical trials conducted in South Africa.