BOSTON: Antibodies grown from some Covid-19 vaccines are less effective in neutralizing new circulating variants of the new coronavirus, such as those first reported in the United Kingdom, South Africa and Brazil, according to a new study.
The research, published in the journal Cell, noted that neutralizing antibodies induced by Pfizer and Moderna Covid-19 vaccines were less effective against the coronavirus variants first described in Brazil and South Africa.
According to scientists, including Alejandro Balazs of Massachusetts General Hospital (MGH) in the United States, neutralizing antibodies work by binding to the virus and blocking it from entering cells, thus preventing infection.
They said that this binding only happens when the forms of the antibody and the virus are perfectly matched to each other “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 will no longer be able to recognize and neutralize the virus.
In the study, the researchers developed tests for Covid-19, comparing how well the antibodies worked against the original strain compared to 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 a professor. medical assistant at Harvard Medical School in the USA.
According to scientists, the two strains first described in Brazil and Japan were five to seven times more resistant than the original progeny of the SARS-CoV-2 virus in 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 Wilfredo Garcia-Beltran, the first author of the study at MGH.
The study noted that the three South African variants, which were the most resistant, shared all three mutations in receptor binding, which may contribute to their high resistance to neutralizing antibodies.
However, scientists have said that the ability of these variants to resist neutralizing antibodies does not mean that vaccines will not be effective.
“The body has other methods of immune protection besides antibodies. Our findings do not necessarily mean that vaccines will not prevent Covid, but only that the portion of antibodies in the immune response may have problems recognizing some of these new variants,” Balazs said.
The researchers added that understanding the mutations that are most likely to allow the virus to evade vaccine-derived immunity is essential to developing next-generation vaccines that can provide protection against new variants.
They said this could also help researchers develop more effective preventive methods, such as large-scale protective vaccines, which act against a wide variety of variants, regardless of the mutations that develop.
The research, published in the journal Cell, noted that neutralizing antibodies induced by Pfizer and Moderna Covid-19 vaccines were less effective against the coronavirus variants first described in Brazil and South Africa.
According to scientists, including Alejandro Balazs of Massachusetts General Hospital (MGH) in the United States, neutralizing antibodies work by binding to the virus and blocking it from entering cells, thus preventing infection.
They said that this binding only happens when the forms of the antibody and the virus are perfectly matched to each other “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 will no longer be able to recognize and neutralize the virus.
In the study, the researchers developed tests for Covid-19, comparing how well the antibodies worked against the original strain compared to 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 a professor. medical assistant at Harvard Medical School in the USA.
According to scientists, the two strains first described in Brazil and Japan were five to seven times more resistant than the original progeny of the SARS-CoV-2 virus in 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 Wilfredo Garcia-Beltran, the first author of the study at MGH.
The study noted that the three South African variants, which were the most resistant, shared all three mutations in receptor binding, which may contribute to their high resistance to neutralizing antibodies.
However, scientists have said that the ability of these variants to resist neutralizing antibodies does not mean that vaccines will not be effective.
“The body has other methods of immune protection besides antibodies. Our findings do not necessarily mean that vaccines will not prevent Covid, but only that the portion of antibodies in the immune response may have problems recognizing some of these new variants,” Balazs said.
The researchers added that understanding the mutations that are most likely to allow the virus to evade vaccine-derived immunity is essential to developing next-generation vaccines that can provide protection against new variants.
They said this could also help researchers develop more effective preventive methods, such as large-scale protective vaccines, which act against a wide variety of variants, regardless of the mutations that develop.