COVID-19: New study finds antibodies may last more than 60 days

Covid-19: A new study has found that antibodies against novel Coronavirus infection may last more than 60 days in a human body. The study, titled ‘SARS-CoV-2 antibody seroprevalence and stability in a tertiary care hospital-setting’ was done by Max Super Specialty Hospital-Saket and the CSIR-Institute for Genomics and Integrative Biology with the data over a period of five months in India. So far, 50 days were considered as an average duration for antibodies to stay. However, the new study begs to differ.

The study observed a pool of 780 people including 448 healthcare workers and 332 individuals who had visited the hospital for Coronavirus testing between April and August this year. It is to note that when a person is infected with any kind of infection, as a natural response, the human body develops antibodies. The presence of antibodies and the duration they are present determines for how long a person can prevent re-infection. “Previously during many viral outbreaks, serological assessment in the community has proven to be useful in understanding the spread of the disease along with chances of development of herd immunity and previous exposure to virus,” the study noted.

According to Dr Sujeet Jha, principal director, Endocrinology, Diabetes & Metabolism, at Max hospital, in India, this recent study is the first preliminary report that points out that antibodies against SARS-CoV-2, once developed, could remain in the body for more than 60 days. Jha added that the follow-up of seropositivity in individuals is still going on and the results can be useful for vaccine development. The study observed an “increasing trend of seropositive cases” among healthcare workers in the last four months. A large number of asymptomatic individuals have been found to be seropositive in Delhi.

Recently, the National Center for Disease Control (NCDC) also conducted a survey on seropositivity in collaboration with the Delhi government between June 27 and July 10, according to which, the seropositivity rate has been recorded at 23.48 per cent. However, the study done at Max Hospital highlighted that the survey was conducted over a short period of time. Since the new study is a longitudinal one and has been done over a period of 5 months, the study claimed that individuals can have an additional immunity for up to a maximum of 83 days.

Around 67 per cent of seropositive cases have been found to be asymptomatic, highlighting that “antibodies can appear in individuals without them having any idea of even being exposed to the virus.” In hospitals, seroprevalence increased from 2.3 per cent in April to 50.6 per cent in July.

Meanwhile in Delhi, more than 2.67 lakh COVID-19 cases have been reported so far where 29,717 are still active. On Saturday, 46 deaths were recorded in the city due to COVID-19 which is the highest in 80 days. This has taken the overall death toll to 5,193.