Washington: Immunity against Covid-19 may persist for at least five months after being infected with the SARS-CoV-2 virus, according to a study led by an Indian-origin researcher.
The researchers from the University of Arizona studied the production of antibodies from a sample of nearly 6,000 people infected with the novel coronavirus.
“We clearly see high-quality antibodies 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 expressed about immunity against Covid-19 not lasting. We used this study to investigate that question and found immunity is stable for at least five months,” who led the study, published in the journal Immunity, alongside Professor Janko Nikolich-Zugich from UArizona.
When a virus first infects cells, the immune system deploys short-lived plasma cells that produce antibodies to immediately fight the virus, the researchers explained.
Those antibodies appear in blood tests within 14 days of infection, they said.
The second stage of the immune response is the creation of long-lived plasma cells, which produce high-quality antibodies that provide lasting immunity, according to the researchers.
Deepta Bhattacharya and Janko Nikolich-Zugich tracked antibody levels over several months in people who tested positive for SARS-CoV-2 antibodies.
They found SARS-CoV-2 antibodies are present in blood tests at viable levels for at least five to seven months, although they believe immunity lasts much longer.
“Whether antibodies provide lasting protection against SARS-CoV-2 has been one of the most difficult questions to answer,” said UArizona Health Sciences Senior Vice President Michael D Dake.
“This research not only has given us the ability to accurately test for antibodies against COVID-19, but also has armed us with the knowledge that lasting immunity is a reality,” Dake said.