Research: Covid-19 antibodies, vaccines may be less effective against new variants

With few exceptions, researchers found more antibody is needed to neutralise the new variants — whether the antibodies were produced in response to vaccination or natural infection.

 

New research indicates that three new, fast-spreading variants of the novel coronavirus (from South Africa, the UK and Brazil) can evade antibodies that work against the original form of the virus that sparked the pandemic. With few exceptions, the researchers found more antibody is needed to neutralise the new variants — whether the antibodies were produced in respnose to vaccination or natural infection, or were purified antibodies intended for use as drugs.

 

The study, from laboratory-based experiments, were published in Nature Medicine on Thursday. According to the researchers, the findings suggest that Covid-19 drugs and vaccines developed thus far may become less effective as the new variants become dominant.

 

The virus SARS-CoV-2 uses its spike protein to latch onto and get inside cells. The spike thus became the prime target for drug and vaccine developers. Then, this winter, fast-spreading variants emerged; all carry multiple mutations in their spike genes, which could lessen the effectiveness of spike-targeted drugs and vaccines now being used.

 

In the lab, researchers tested the ability of antibodies to neutralise the three virus variants. They tested the variants against antibodies in the blood of people who had recovered from SARS-CoV-2 infection or were vaccinated with the Pfizer vaccine. They also tested antibodies in the blood of mice, hamsters and monkeys that had been vaccinated with an experimental Covid-19 vaccine, developed at Washington University School of Medicine. The University said in a press statement that the UK variant could be neutralised with similar levels of antibodies as needed to neutralise the original virus, but the other two variants required from 3.5 to 10 times as much antibody.

 

Senior author Michael S Diamond was quoted as saying: “We’re concerned that people whom we’d expect to have a protective level of antibodies because they have had Covid-19 or been vaccinated against it, might not be protected against the new variants. There’s wide variation in how much antibody a person produces in response to vaccination or natural infection. Some people produce very high levels, and they would still likely be protected against the new, worrisome variants. But some people, especially older and immunocompromised people, may not make such high levels of antibodies. If the level of antibody needed for protection goes up tenfold, as our data indicate it, they may not have enough…”

https://indianexpress.com/article/explained/new-findings-suggest-covid-antibodies-vaccines-may-be-less-effective-against-variants-7216233/