Scientists in the United States and Switzerland have confirmed that the body of people who have recovered from COVID-19 is able to fight against re-infection thanks to cells that can remember the virus. This is reported in an article published in the journal Nature.
Researchers studied 87 recovered people 1.3 and 6.2 months after infection and determined that although antibodies to SARS-CoV-2 may fade over time, they maintain a certain level of specific memory B cells that recognize the virus. These cells resume production of antibodies to coronavirus if the virus re-enters the body. In addition, the antibodies are resistant to mutations in SARS-CoV-2, which indicates the evolution of the humoral response and the maintenance of the immune response against mutated forms of the pathogen.
Previous studies have shown that the titers of neutralizing IgM and IgG antibodies targeting the coronavirus S-protein are rapidly declining after COVID-19, which has been a cause for concern among scientists and specialists, fearing that vaccines will be 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.
So, earlier, Australian scientists determined the duration of immunity in people who have had COVID-19. It is at least eight months. This proves that the SARS-CoV-2 coronavirus vaccines will be effective for a long time after injection.