Antibodies raised by COVID-19 vaccine less effective against certain coronavirus variants: study

Antibodies induced by some COVID-19 vaccines are less effective at neutralizing new circulating variants of the novel coronavirus, such as those reported in the UK, Brazil and South Africa, according to a new study.

The study was published in the journal Cell and noted that the neutralizing antibodies induced by the Pfizer and Moderna COVID 19 vaccines were less effective against the coronavirus variants first found in South Africa and Brazil.

According to scientists, neutralizing antibodies work by binding tightly to the virus and preventing it from entering cells and thus preventing infection. That said, this binding only occurs when antibodies and viruses match perfectly, like a key in a lock.

If the shape of the virus changes when the antibody attaches to it, the antibody may no longer be able to recognize and neutralize the virus.

The scientists compared the effectiveness of the antibodies against the original strain against the newer variants.

When scientists tested the new strains against vaccine-induced neutralizing antibodies, they found that the three new strains first described in South Africa were 20 to 40 times more resistant to neutralization.

The two strains first described in Brazil and Japan were five to seven times more resistant than the original SARS-CoV-2 virus line from Wuhan, China.

“In particular, we found that mutations in a specific part of the spike protein called the receptor binding domain were more likely to help the virus resist neutralizing antibodies,” said one study author.

However, the ability of these variants to resist neutralizing antibodies does not mean that the vaccines will not be effective.

“The body has other methods of immune protection in addition to antibodies. Our results do not necessarily mean that vaccines will not prevent COVID, only that the antibody part of the immune response may have difficulty recognizing some of it. these new variants, ”the scientists said. .

To develop the next generation, it is important to understand which mutations are most likely to allow the virus to escape vaccine-derived immunity.

The study may also help researchers develop more effective preventive methods, such as a widely protective vaccine that works against a wide variety of variants, regardless of the number of mutations that develop.