COVID-19 immunity lasts at least eight months: Study
People who have recovered from coronavirus have immune memory to protect against re-infection for at least eight months, according to a new study. While earlier studies have shown that antibodies against the coronavirus wane after the first few months of infection, the new research puts these concerns to rest. This study also provides evidence that COVID-19 vaccines will work for long periods.
According to the study published in Science Immunology, specific cells within the immune system, called memory B cells, "remember" infection by the virus, and if re-exposed to the virus, trigger a protective immune response through rapid production of protective antibodies.
Scientists found that the antibodies against the virus started to drop off after 20 days post-infection, amongst a cohort of COVID-19 patients in the study. However, they said the patients continue to have memory B cells that recognized the spike protein, and the nucleocapsid proteins. The researchers said these virus-specific memory B cells were stably present as far as eight months after infection.
Scientists believe the findings explain why there have been very few examples of genuine re-infection across those who have tested positive for the virus globally. The study co-author Menno van Zelm, from the Monash University said, "These results are important because they show, definitively, that patients infected with the COVID-19 virus do in fact retain immunity against the virus and the disease."
Menno van Zelm said, "This has been a black cloud hanging over the potential protection that could be provided by any COVID-19 vaccine and gives real hope that, once a vaccine or vaccines are developed, they will provide long-term protection."