Pfizer effective against the Indian mutant, but
The Pfizer vaccine produces antibodies capable of protecting against the Indian variant of the Coronavirus, but “a little less effectively” in the laboratory, according to a study conducted by researchers at the Institut Pasteur.
In people who received two doses of the Pfizer vaccine, the antibodies were effective against the British mutant, but slightly less effective against the Indian mutant studied, according to this study, published on the site “BioRXIV”.
Olivier Schwarz, co-author of the study and director of the virology and immunology unit at the Institut Pasteur (Paris), confirmed that despite “the slightly low efficacy according to laboratory experiments, the Pfizer vaccine probably protects ”from the virus.
The researchers also tested the effectiveness of the AstraZeneca vaccine on these mutated versions, but only from sera from people who received the first dose of the British vaccine, and they had no “ability to obtain samples from people with received both doses ”. when the study was conducted, Schwartz told AFP.
Since the European Union started using this vaccine in February and recommended a 12 week interval between the two doses, the second dose was not given until the end of April and a number limited to people, as it was limited to people over 55. and because of the reluctance of part of the population to receive it.
The results of the study, which was carried out with French university hospitals, show that a single dose of the vaccine AstraZeneca effective against the British mutant has “limited effectiveness against the Indian and South African mutant versions”.
Therefore, a single dose of this vaccine appears “little or not at all effective” against the Indian mutant, according to the researcher.
The Indian mutant (B.1.617), discovered in India in October 2020, has since spread to many countries, including Great Britain.
Its main strains or its three subgroups (B.1.617.1), (B.1.617.2) and (B.1.617.3) contain certain mutations that can increase its ability to escape the immune system, that is that is, its ability to reduce the activity of antibodies derived from vaccines, which are antibodies acquired naturally or received as part of a treatment.
The researchers specifically studied the strain B.1.617.2, which is more transmissible than the other two strains and was recently discovered in around ten countries.
“We show that this rapidly spreading mutant has acquired partial resistance to the antibodies,” said Schwarz.
He added that, for example, “sera from patients who contracted Covid-19 and obtained up to 12 months after symptoms, as well as people who received the Pfizer vaccine, remain resistant but three to six times less effective. against (the Indian mutant) B.1.617.2 compared to BPI.1.1.7 (British mutant).