Study: Covid-19 immunity lasts at least 8 months
By: Team Ifairer | Posted: 23-12-2020
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People who have recovered from the novel coronavirus infection have immune memory to protect against reinfection for at least eight months, according to a new study which provides strong evidence for the likelihood that COVID-19 vaccines will work for long periods. While earlier studies have shown that antibodies against the coronavirus wane after the first few months of infection, raising concerns that people may lose immunity quickly, the new research, published in the journal Science Immunology, puts these concerns to rest.
According to the scientists, including those from Monash University in Australia, specific cells within the immune system called memory B cells, "remembers" infection by the virus, and if re-exposed to the virus, triggers a protective immune response through rapid production of protective antibodies. In the study, the researchers recruited a cohort of 25 COVID-19 patients and took 36 blood samples from them from Day 4 post infection to Day 242 post infection.
The scientists found that antibodies against the virus started to drop off after 20 days post infection. However, they said all patients continued to have memory B cells that recognised one of two components of the virus - the spike protein which helps the virus enter host cells, and the nucleocapsid proteins. Based on their analysis, the researchers said these virus-specific memory B cells were stably present as far as eight months after infection.