"Testing of an entire Italian town shows antibody levels remain high nine months after SARS-CoV-2 infection, whether symptomatic or asymptomatic. Researchers from the University of Padua and Imperial College London tested more than 85 percent of the 3,000 residents of Vo', Italy, in February/March 2020 for infection with SARS-CoV-2, the virus that causes COVID-19, and tested them again in May and November 2020 for antibodies against the virus. The team found that 98.8 percent of people infected in February/March showed detectable levels of antibodies in November, and there was no difference between people who had suffered symptoms of COVID-19 and those that had been symptom-free. The results are published today in Nature Communications."

https://www.sciencedaily.com/releases/2021/07/210719103033.htm