Scientists in the US and Switzerland have confirmed that people who have had COVID-19 can fight against reinfection thanks to cells capable of remembering the virus.
The researchers studied 87 recovered individuals 1.3 and 6.2 months after infection and determined that although antibodies to SARS-CoV-2 may disappear over time, they maintain some level of specific memory B-cells that recognize the virus. These cells resume production of antibodies to the coronavirus should the virus re-enter the body. In addition, the antibodies appear to be resistant to SARS-CoV-2 mutations, indicating an evolving humoral response and maintenance of the immune response against the mutated forms of the pathogen.
Previous studies have shown that titers of neutralizing antibodies IgM and IgG targeting the coronavirus S-protein declined rapidly after COVID-19, leading scientists and experts to worry that vaccines would prove ineffective in the fight against the pandemic. However, there is now growing evidence that long-term immunity is supported by other components of the immune system.
For example, Australian scientists previously determined the duration of immunity in people who have had COVID-19. It is a minimum of eight months. This proves that vaccines against SARS-CoV-2 coronavirus will be effective for a long time after injection.