COVID-19 patients who recover still have significant immunity for up to eight months after infection – a promising sign that there is lasting protection against the deadly disease, according to a new study.
The paper, published Wednesday in the journal Science, analyzed blood samples from 188 patients, mostly from San Diego, who had contracted the virus.
“Originally, there was a lot of concern that this virus might not generate much memory. Instead, the immune memory looks pretty good, ”study co-author Shane Crotty, a researcher at the La Jolla Institute for Immunology, told MIT Technology Review.
Crotty and his team found that most patients had virus-specific antibodies in their bloodstream six months or more after infection.
But more importantly, they had robust levels of memory B cells, which make antibodies.
In some cases, they had more of these immune cells eight months after their infection than after just one.
If the person becomes infected again, the memory B cells can be a blueprint of how to fight the virus, even if they have low levels of antibodies.
The findings suggest that a person who has recovered can have years of immunity.
Crotty said they will continue to monitor study participants to see if they still have the same number of B cells 12 and 18 months after infection.
But despite the promising findings, Crotty reiterated that reinfection is still possible.
“Immunity varies from person to person, and unusual individuals with weak immune memory may still be prone to reinfection,” he said.