Regardless of their detectable antibody levels, most COVID-19 survivors are likely to have lasting protection against severe COVID-19 if they become reinfected, thanks to other components of the body's immune response that remember the new coronavirus in different ways, researchers say.

In a study of 185 patients, including 41 who had been infected more than six months earlier, scientists at La Jolla Institute for Immunology in California found that multiple branches of the immune system - not just antibodies - recognized the novel coronavirus for at least eight months.

For example, so-called memory B cells that could recognize the virus and produce antibodies to fight it were more abundant six months after infection than at one month, they reported in a paper posted on Monday on bioRxiv ahead of peer review.

The new findings "suggest that the immune system can remember the virus for years, and most people may be protected from severe COVID-19 for a substantial time," said study leaders Shane Crotty and Alessandro Sette.