People who have recovered from Covid-19 only need one dose of the vaccine. A second shot is important for those who haven’t had Covid-19 to achieve strong immunity, a study suggests.
The study, led by researchers at the University of Pennsylvania in the United States, found that Covid survivors had a robust antibody response after the first dose of mRNA vaccine, but little immune benefit was seen after the second dose. On the other hand, those who did not have Covid-19 – called naive Covid – only had a complete immune response after receiving their second dose of the vaccine, which reinforces the importance of completing the two recommended doses. to achieve high levels of immunity. Doses are optimal for inducing strong antibody and B-cell responses in patients immunologically naive for SARS-CoV-2, and immunization-induced antibodies could protect against the more infectious and fatal South African variant, said Researchers.
The findings, published in the journal Science Immunology, provide more information on the underlying immunobiology of mRNA vaccines, which could help shape future vaccine strategies.
“These results are encouraging for the efficacy of vaccines in the short and long term, and it adds to our understanding of the immune response of the mRNA vaccine through analysis of memory B cells,” said E John Wherry, director of the Penn Institute of Immunology.
The human immune response to vaccines and infections leads to two major outcomes: the production of antibodies that provide rapid immunity, and the creation of memory B cells, which contribute to long-term immunity.
For the study, the team included 44 healthy people who received the BioNTech / Pfizer or Moderna mRNA vaccine. Of this cohort, 11 had a previous Covid-19 infection. Blood samples were taken for deep immune analyzes four times before and after the vaccine doses. (IANS)