Levels of an antibody found in recovered Covid-19 patients fell sharply in 2-3 months after infection for both symptomatic and asymptomatic patients, according to a Chinese study, raising questions about the length of any immunity against the novel coronavirus.

from Times of India https://timesofindia.indiatimes.com/home/science/new-research-casts-doubts-on-long-term-covid-immunity/articleshow/76521166.cms