A study on 614 fully vaccinated health workers at ICMR’s Regional Medical Research Centre in Bhubaneswar showed a significant drop in Covid antibodies within four months after complete vaccination. In this study, which was done when India witnessed a deadly delta variant surge, 308 participants were given two doses of the Covishield vaccine and 306 were given two doses of Covaxin. Out of these 614 healthcare workers, 81 people got infected with Covid-19 for the first time. Among the 257 participants with a previous history of Covid-19, 33 were reinfected even after being inoculated with both doses of a Covid vaccine. Meanwhile, antibody level for those who got Covaxin started to decrease significantly and antibodies for Covishield recipients started waning significantly after 6 months from the first vaccine shot.
“In Covaxin, antibodies started declining in the second month after vaccination. In Covishield, antibodies started declining after the fourth month of vaccination,” said Dr Bhattacharya, one of the authors of the study. “We report a significant decline of antibody post 2 months and 4 months among Covaxin and Covishield recipients after two doses of the Covaxin and Covishield,” she added however, waning antibodies does not mean that one is not protected at all.
