COVID-19 patients who have recovered still have significant immunity up to eight months after infection – a promising sign that there is lasting protection against the deadly disease, according to a new study.
The article, published Wednesday in the journal Science, analyzed blood samples from 188 patients, mostly from San Diego, who contracted the virus.
“Initially, there was a lot of concern that this virus would not induce a lot of memory. Instead, immune memory looks very good, ”co-author Shane Crotty, a researcher at the La Jolla Institute for Immunology, told the 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 most importantly, they had robust levels of memory B cells, which create antibodies.
In some cases, they had more of these immune cells eight months after infection than after just one.
If the person is infected again, memory B cells can provide a plan for how to fight the virus, even if they have low levels of antibodies.
The findings suggest that a person who has recovered may have immunity that lasts for years.
Crotty said he will continue to monitor study participants to see if they still have the same B-cell count levels 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 poor immune memory may still be susceptible to reinfection,” he said.