Hyderabad: COVID-19 antibodies may not last more than a couple of months, an Indian study conducted on 801 frontline medics affected by COVID-19 showed.
The study was carried out on infected healthcare staff of in Mumbai and it showed that 28 of those tested positive had no antibodies in a sero survey done weeks later.
“Our study of 801 healthcare staff from JJ, GT Hospital and St George’s Hospital included 28 who had tested positive for COVID-19 (on RT-PCR) seven weeks prior (in late April-early May),” said the study’s main author Dr Nishant Kumar.
However, none of the 28 showed any antibodies in a sero survey done in June, according to the preprint of the study that will appear in the September issue of the ‘International Journal of Community Medicine and Public Health’.
The JJ Hospital sero survey had 34 others who tested PCR positive for COVID-19 three weeks and five weeks prior respectively. “While 90 per cent of those in the three-week group had antibodies, less than half (38.5 per cent) in the five-week group had antibodies,” said Dr Kumar.
However, some public health experts were not convinced with the early decay of antibodies as studies in the West have shown asymptomatic patients do not have the same level of antibodies as patients who have had a prolonged or severe COVID infection.
“We don’t know if the 28 patients in the JJ study had suffered asymptomatic form of the virus or if they had symptoms. Patients who had longer symptomatic disease have antibodies for at least three to four months,” said epidemiologist Giridhar R Babu from the Public Health Foundation of India.