Covid-19: Antibodies last at least nine months after infection, finds study

London, July 19

Antibody levels remain high nine months after infection with SARS-CoV-2, the virus that causes Covid-19, whether symptomatic or asymptomatic, according to a study published on Monday that analysed data from an entire Italian town.

Researchers from the University of Padua in Italy and Imperial College London in the UK tested over 85 per cent of the 3,000 residents of Vo', Italy, in February and March last year for infection with SARS-CoV-2, the virus that causes Covid-19. They then tested them again in May and November 2020 for antibodies against the virus. The study, published in the journal Nature Communications, found that 98.8 per cent of people infected in February and March showed detectable levels of antibodies in November. The results also show that there was no difference between people who had suffered symptoms of Covid-19 and those that had been symptom-free. "We found no evidence that antibody levels between symptomatic and asymptomatic infections differ significantly, suggesting that the strength of the immune response does not depend on the symptoms and the severity of the infection,” said study lead author Ilaria Dorigatti, from Imperial College. "However, our study does shows that antibody levels vary, sometimes markedly, depending on the test used," Dorigatti said. PTI