"Levels of antibodies against SARS-CoV-2, the virus that causes COVID-19, dropped dramatically over the first 3 months of infection in 34 people recovered from mild illness, University of California at Los Angeles researchers have found. Their
research letter, published yesterday in the
New England Journal of Medicine, said that antibody levels against the novel coronavirus decreased by about half every 73 days and, if that rate were sustained, would be depleted within about a year."
www.cidrap.umn.edu
"Data indicate that neutralising antibodies last for several months in patients with covid-19 but gently fall in number over time." -
https://www.bmj.com/content/373/bmj.n1605