COVID-19 Antibodies Persist at Least Nine Months after Infection: Study

New Delhi: Antibodies in COVID-19 patients remain high even nine months after infection, according to a study which tested almost the entirety of a small Italian town.

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.

Antibody levels were tracked using three ‘assays’ – tests that detect different types of antibodies that respond to different parts of the virus. The results showed that while all antibody types showed some decline between May and November, the rate of decay was different depending on the assay.

The team also found cases of antibody levels increasing in some people, suggesting potential re-infections with the virus, providing a boost to the immune system.