The novel coronavirus continues to be a headache for medical professionals around the globe as researchers continue to investigate the virus and whether those who do get sick from it are immune from potential reinfection.
However, a breakthrough study found that people can stay immune for at least several months after being infected by SARS-CoV-2, the virus behind COVID-19.
Researchers from the University of Arizona examined nearly antibodies samples from nearly 6,000 people to find that immunity can last for at least five months.
The study, published in the journal Immunity, helps calm some concerns by people after immunity against the coronavirus reportedly did not last as long as some hoped.
“We clearly see high-quality antibodies still being produced five to seven months after SARS-CoV-2 infection,” Deepta Bhattacharya, PhD, associate professor at the University of Arizona, said in a press release. “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.”
Bhattacharya conducted the research with Janko Nikolich-Zugich, a professor at the University of Arizona. Together, the pair tracked antibody levels of people who tested positive for SARS-CoV-2 antibodies for several months, where they found that antibodies were present in blood work for at least five to seven months. That discovery has some considering that a lasting immunity is a possibility despite previous research finding that antibodies levels can drop much sooner as time goes on. That would suggest that immunity only lasts for a short while, but Bhattacharya said something can be learned from the first SARS coronavirus.
“The latest time-points we tracked in infected individuals were past seven months, so that is the longest period of time we can confirm immunity lasts,” Bhattacharya explained. “That said, we know that people who were infected with the first SARS coronavirus, which is the most similar virus to SARS-CoV-2, are still seeing immunity 17 years after infection. If SARS-CoV-2 is anything like the first one, we expect antibodies to last at least two years, and it would be unlikely for anything much shorter.”
Of the nearly 6,000 antibodies tests reviewed, only one returned as a false positive, according to researchers.
“When we began, the first test we developed was 99% accurate for measuring antibodies in one part of the virus,” Nikolich-Žugich said. “We decided to confirm, and hopefully improve, that accuracy level by looking at another part of the virus that makes antibodies independent of the first location. We then validated that test, knowing some people will make antibodies more consistently for one part of the virus than the other. We put the two tests together, and only people who show antibody production for both parts of the test are determined to be positive.”