Individuals who have had COVID-19 may have long-term immunological protection against new virus types, but experts believe immunisation is still the best way to prevent reinfection.
Their modest new research investigated blood samples from 24 persons with COVID-19 infections that ranged in severity from asymptomatic to severe enough to need hospitalisation.
While those with moderate or no symptoms did not necessarily have SARS-CoV-2-specific antibodies in their blood, all 24 had memory B cells, which generated SARS-CoV-2 antibodies in response to viral exposure.
“We believe that these findings provide us with legitimate cause for hope,” said senior author Dr. Bill Messer, an assistant professor of molecular microbiology and immunology at Oregon Health & Science University.
“The present versions of concern are unlikely to successfully bypass the immune system of individuals who have recovered from infection,” Messer stated in a university news statement.
These memory B cells appeared to detect not just the original virus, but also so-called variations of concern 11 months after infection. The findings were published in the Journal of Infectious Diseases earlier this year.
However, the researchers stated that they cannot be certain that the B-cell response they observed will produce an efficient immune response against viral variations.
Messer emphasised that immunisation provides the best protection against reinfection and also against serious disease or death in those who have never had COVID-19.
“At this moment, we definitely lack sufficient longterm data,” said study lead author Zoe Lyski, a graduate student in Messer’s group. “These facts do allow us to be positive about the variations’ handling. This indicates that if an individual is exposed to a variation of concern, the memory B cells created by vaccination or spontaneous infection are ready to respond.”