According to a study conducted by a researcher of Indian origin in the United States, immunity to COVID-19 can persist for at least five months after infection with the SARS-CoV-2 virus.
The University of Arizona researchers looked at the production of antibodies from a sample of nearly 6,000 people infected with the novel coronavirus.
“We can clearly see that high quality antibodies are still being produced five to seven months after SARS-CoV-2 infection,” said Deepta Bhattacharya, associate professor at the University of Arizona.
“Many concerns have been raised about non-permanent immunity to COVID-19. We used this study to investigate this issue and found that immunity is stable for at least five months,” he headed today in Immunity magazine published study together with Professor Janko Nikolich-Zugich from UArizona.
When a virus first infects cells, the immune system uses short-lived plasma cells that produce antibodies to fight the virus immediately, the researchers said.
These antibodies show up in blood tests within 14 days of infection.
The second stage of the immune response, according to the researchers, is the formation of long-lived plasma cells that produce high quality antibodies that provide long-lasting immunity.
Deepta Bhattacharya and Janko Nikolich-Zugich followed the antibody levels over several months in people who tested positive for SARS-CoV-2 antibodies.
They found that SARS-CoV-2 antibodies were present in viable amounts in blood tests for at least five to seven months, although they believe immunity is much longer lasting.
“Whether antibodies provide permanent protection against SARS-CoV-2 was one of the most difficult questions to answer,” said Michael D Dake, senior vice president of UArizona Health Sciences.
“This research has not only given us the ability to accurately test for antibodies to COVID-19, it has also provided us with the knowledge that lasting immunity is a reality,” said Dake.
Previous studies have extrapolated antibody production from initial infections and suggested that antibody levels drop rapidly after infection, providing only short-term immunity.
Mr. Bhattacharya believes that these conclusions focused on short-lived plasma cells and did not take into account long-lived plasma cells and the high-affinity antibodies they produce.
“The last time we recorded an infected person was for the past seven months, which is the longest time we can confirm immunity has persisted,” said Bhattacharya.
He said that people infected with the first SARS coronavirus, which is most similar to SARS-CoV-2, still see immunity 17 years after being infected.
“If SARS-CoV-2 is anything like the first, we expect antibodies to last at least two years, and anything much shorter is unlikely to happen,” the scientist added.
(Except for the headline, this story was not edited by GossipMantri staff and posted from a syndicated feed.)