People with Covid-19 infection are likely to have strong immunity against coronavirus for at least a year after they were initially infected, according to a study. The study, led by scientists at the Rockefeller University, also showed that vaccination boosts the immunity these individuals naturally develop after the infection, so much that they are likely to be protected even from the emerging variants.
The study is available on bioRxiv ahead of publication in a peer-reviewed journal.
The team analysed antibodies present in the blood of Covid patients and tracked the evolution of these mutable molecules.
The 63 people in the study had Covid in the spring of last year. Data from their follow-ups show that, over time, antibodies produced by the immune system's memory B cells got better and better at neutralising SARS-CoV-2, suggesting that these people were developing an improved, long lasting defense against the virus.
These antibodies were further enhanced among 26 people in the group who had received at least one dose of the Moderna or Pfizer vaccine.
This subset of people developed antibodies that are exceptionally resistant to the most concerning SARS-CoV-2 variants, such as those first isolated in the UK, South Africa, and New York City.
These potent antibodies are produced by groups of highly evolved memory B cells, which expand dramatically after a nudge by the vaccines, the team found.
The findings suggest that well-timed boosters with the current vaccines may provide additional protection in people who have never had the disease.