BOSTON: Antibodies raised by some Covid-19 vaccines are less effective in 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, noted that the neutralizing antibodies induced by the Pfizer and Moderna Covid-19 vaccines were less effective against the coronavirus variants first described in Brazil and South Africa.
According to the scientists, including Alejandro Balazs of Massachusetts General Hospital (MGH) in the US, neutralizing antibodies work by binding tightly to the virus and preventing it from entering the cells, preventing infection.
They said this binding only takes place when the shape of the antibody and the virus are perfectly matched “like a key in a lock.”
If the shape of the virus changes where the antibody attaches to it – in this case, in the spike protein of the new coronavirus – they said the antibody may also be unable to recognize and neutralize the virus.
In the study, the researchers developed assays for Covid-19, comparing how well the antibodies worked against the original strain versus the new variants.
“When we tested these new strains against vaccine-induced neutralizing antibodies, we found that the three new strains first described in South Africa were 20-40 times more resistant to neutralization,” said Balazs, who is also an assistant professor. medicine is at Harvard. 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 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, the receptor binding domain, more likely helped the virus to resist the neutralizing antibodies,” said Wilfredo Garcia-Beltran, lead author of the HGH study.
The study noted that the three South African variants, which were the most resistant, all shared 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 neutralizing antibodies doesn’t mean the vaccines won’t be effective.
“The body has other methods of immune protection in addition to antibodies. Our findings do not necessarily mean that vaccines will not prevent Covid, just that the antibody portion of the immune response may have difficulty recognizing some of these new variants,” Balazs said.
The researchers added that understanding which mutations are most likely to allow the virus to evade vaccine-derived immunity is essential to develop next-generation vaccines that can protect against new variants.
They said this could also help researchers develop more effective prevention methods, such as broadly protective vaccines that work against a wide variety of variants, regardless of which mutations develop.
The research, published in the journal Cell, noted that the neutralizing antibodies induced by the Pfizer and Moderna Covid-19 vaccines were less effective against the coronavirus variants first described in Brazil and South Africa.
According to the scientists, including Alejandro Balazs of Massachusetts General Hospital (MGH) in the US, neutralizing antibodies work by binding tightly to the virus and preventing it from entering the cells, preventing infection.
They said this binding only takes place when the shape of the antibody and the virus are perfectly matched “like a key in a lock.”
If the shape of the virus changes where the antibody attaches to it – in this case, in the spike protein of the new coronavirus – they said the antibody may also be unable to recognize and neutralize the virus.
In the study, the researchers developed assays for Covid-19, comparing how well the antibodies worked against the original strain versus the new variants.
“When we tested these new strains against vaccine-induced neutralizing antibodies, we found that the three new strains first described in South Africa were 20-40 times more resistant to neutralization,” said Balazs, who is also an assistant professor. medicine is at Harvard. 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 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, the receptor binding domain, more likely helped the virus to resist the neutralizing antibodies,” said Wilfredo Garcia-Beltran, lead author of the HGH study.
The study noted that the three South African variants, which were the most resistant, all shared 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 neutralizing antibodies doesn’t mean the vaccines won’t be effective.
“The body has other methods of immune protection in addition to antibodies. Our findings do not necessarily mean that vaccines will not prevent Covid, just that the antibody portion of the immune response may have difficulty recognizing some of these new variants,” Balazs said.
The researchers added that understanding which mutations are most likely to allow the virus to evade vaccine-derived immunity is essential to develop next-generation vaccines that can protect against new variants.
They said this could also help researchers develop more effective prevention methods, such as broadly protective vaccines that work against a wide variety of variants, regardless of which mutations develop.