Covid antibodies last at least seven months
Number remains stable or even increases after this period, according to a study
BarcelonaSeven months after infection, a person retains the same level of antibodies against covid - or more. This is the main conclusion of a study by the Barcelona Institute for Global Health (ISGlobal), a centre supported by the La Caixa Foundation, in collaboration with Barcelona's Hospital Clínic. Between March and October 2020, the researchers analysed samples from 578 health professionals, measuring the level and type of antibodies (IgA, IgM or IgG) against six different covid antigens.
The results indicate that IgG antibodies (including neutralising antibodies) remained stable over seven months, which confirms other recent studies. "Surprisingly, in 75% of people there was even an increase in anti-Spike IgG antibodies after five months, without any evidence that they had been re-exposed to the virus," says senior co-author Gemma Moncunill, who adds that no reinfections were detected among the cohort of healthcare workers they studied.
In parallel, they analysed the presence of antibodies against the four coronaviruses that cause the common cold. The researchers suggest that these antibodies could confer cross-protection against infection or covid disease: "Cross-protection has not been confirmed, but it could help to explain the different susceptibility of the population to the disease", says ISGlobal researcher Carlota Dobaño, who led the study.