The study specifically estimates that antibodies to SARS-CoV-2 drop sharply in the first three months after infection, dropping by half every 73 days. At this rate, the antibodies disappear almost entirely over a year. This result confirms previous studies which also suggested this short duration, but the study clarifies it for the first time and thus suggests the theoretical rhythm of the vaccination, if necessary.
A very rapid decline in the level of anti-SARS-Cov-2 antibodies, in just a few weeks.
Out of 80 post-COVID-19 volunteer participants, the researchers tracked the immunity of 20 women and 14 men recovered from benign forms of the disease. Antibody tests were done on average every 36 days after the first symptoms of infection. The analysis results in this very rapid decline in the level of antibodies, over a few weeks.
And the protective role of antibodies against SARS-CoV-2 remains to be evaluated, these antibodies are generally a correlate of antiviral immunity, and the levels of anti-binding domain antibodies correspond to plasma activity against the virus. In this study, the early disintegration of antibodies is exponential (see visual opposite) and faster than in the case of the coronavirus SARS-CoV-1 (SARS). Finally, it is difficult to extrapolate beyond the observation period of about 90 days, but it is likely that the disintegration of the antibodies then slows down.
“The results raise concerns that humoral immunity may not last long in people with mild illness,”
write the researchers. However, these patients make up the majority of people with COVID-19.
The results raise concerns about collective immunity and incidentally about “immunity passports”. Then, they ask the question of the reliability of antibody tests and the durability of the antibody-based vaccines themselves.