BOSTON: Antibodies raised by some Covid-19 vaccines are less effective at neutralizing new, circulating variants of the new coronavirus, such as those first reported in the UK, South Africa and Brazil, according to ‘ a new study.
The research, published in the journal Cell, found that the neutralizing antibodies caused by the Pfizer and Moderna Covid-19 vaccines are less effective against the coronavirus variants first described in Brazil and South Africa.
According to scientists, including Alejandro Balazs of the Massachusetts General Hospital (MGH) in the USA, neutralizing antibodies work by binding tightly to the virus and preventing it from entering cells and thus preventing infection.
They said that this binding only takes place when the shape of the antibody and the virus are perfectly matched to each other, like a key in a lock. ‘
If the form of the virus changes where the antibody attaches to it – in this case in the peak protein of the new coronavirus – they said that the antibody may also no longer recognize and neutralize the virus.
In the study, the researchers developed tests for Covid-19, comparing how well the antibodies against the original strain work against the new variants.
“When we tested these new strains against neutralizing antibodies introduced by vaccine, we found that the three new strains first described in South Africa are 20-40 times more resistant to neutralization,” Balazs said. . Medical School in the USA.
According to the scientists, the two strains first described in Brazil and Japan were five to seven times more resistant compared to the original SARS-CoV-2 virus from Wuhan, China.
“In particular, we found that mutations in a specific part of the ear protein, called the receptor binding domain, were likely to help the virus resist the neutralizing antibodies,” said Wilfredo Garcia-Beltran, first author of the MGH study.
The study noted that the three South African variants, which were the most stable, all shared three mutations in the receptor binding domain, which may contribute to their high resistance to neutralizing antibodies.
However, the scientists said that the ability of these variants to resist non-neutralizing antibodies does not mean that the vaccines will not be effective.
“The body has other immune protection methods besides antibodies. Our findings do not necessarily mean that vaccines will prevent Covid, but only that the antibody portion of the immune response is having trouble recognizing some of these new variants,” Balazs said.
The researchers added that it is important to develop the next generation of vaccines that can provide protection against new variants, to understand which mutations the virus is likely to evade the immunity of the vaccine.
They said it could also help researchers develop more effective prevention methods, such as broad-spectrum vaccines that work against a wide range of variants, regardless of which mutations develop.
The research, published in the journal Cell, found that the neutralizing antibodies caused by the Pfizer and Moderna Covid-19 vaccines are less effective against the coronavirus variants first described in Brazil and South Africa.
According to scientists, including Alejandro Balazs of the Massachusetts General Hospital (MGH) in the USA, neutralizing antibodies work by binding tightly to the virus and preventing it from entering cells and thus preventing infection.
They said that this binding only takes place when the shape of the antibody and the virus are perfectly matched to each other, like a key in a lock. ‘
If the form of the virus changes where the antibody attaches to it – in this case in the peak protein of the new coronavirus – they said that the antibody may also no longer recognize and neutralize the virus.
In the study, the researchers developed tests for Covid-19, comparing how well the antibodies against the original strain work against the new variants.
“When we tested these new strains against neutralizing antibodies introduced by vaccine, we found that the three new strains first described in South Africa are 20-40 times more resistant to neutralization,” Balazs said. . Medical School in the USA.
According to the scientists, the two strains first described in Brazil and Japan were five to seven times more resistant compared to the original SARS-CoV-2 virus from Wuhan, China.
“In particular, we found that mutations in a specific part of the ear protein, called the receptor binding domain, were likely to help the virus resist the neutralizing antibodies,” said Wilfredo Garcia-Beltran, first author of the MGH study.
The study noted that the three South African variants, which were the most stable, all shared three mutations in the receptor binding domain, which may contribute to their high resistance to neutralizing antibodies.
However, the scientists said that the ability of these variants to resist non-neutralizing antibodies does not mean that the vaccines will not be effective.
“The body has other immune protection methods besides antibodies. Our findings do not necessarily mean that vaccines will prevent Covid, but only that the antibody portion of the immune response is having trouble recognizing some of these new variants,” Balazs said.
The researchers added that it is important to develop the next generation of vaccines that can provide protection against new variants, to understand which mutations the virus is likely to evade the immunity of the vaccine.
They said it could also help researchers develop more effective prevention methods, such as broad-spectrum vaccines that work against a wide range of variants, regardless of which mutations develop.