Antibodies in persons who received Covishield declined after 3 months
A recent study by ICMR-regional medical research centre (RMRC), Bhubaneswar has revealed a disturbing trend in subjects who received Covaxin and Covishield vaccines for protection from Covid-19. The study revealed that antibodies levels in persons who received Bharat Biotech’s Covid-19 vaccine Covaxin came down after 2 months. Similarly, the study revealed that subjects who received Astrazeneca’s Covishield reported antibodies levels declining after three months. The study involved sampling from 614 participants.
Speaking to India Today TV, Dr Devdutta Bhattacharya, senior scientist at ICMR-regional medical research centre (RMRC), Bhubaneswar, revealed that among the 614 samples taken from the participants, 308 (50.2 per cent) got Covishield vaccines and the rest 306 (49.8 per cent) got vaccinated with Covaxin. Among the participants, 81 reported breakthrough cases and vaccination acted as a booster. The remaining 533 healthcare workers without any post-vaccination infection showed a remarkable decrease in antibodies.
ICMR to continue follow up studies to gauge antibody persistence
According to Dr Devdutta Bhattacharya, these are only preliminary findings and the study is just a part of a long cohort follow-up study. ICMR is planning to continue follow up studies for about two years to see the antibody persistence.
Dr Devdutta said was quoted saying that the study found that the antibody level of Covaxin recipients is decreasing after two months of complete vaccination, while it is three months in the case of Covishield recipients.
The study, which started on March 2021, was undertaken to study IgG (Immunoglobulin G, the most common antibody) levels in health care workers with completed dose of either Covaxin or Covishield.
Study done for 24 weeks after the first dose
The study was done for 24 weeks after the first dose of either one of the vaccines. The parameters which were checked included titer, concentration, clinical growth and persistence of vaccine-induced SARS-CoV-2 antibodies.
ICMR-RMRC, Bhubaneswar Director Sanghamitra Pati added that if there was a fall in antibody levels, there is a persistence of antibody levels and the study continued to follow them. The study will be carried out for another six months before it can be ascertained whether a booster dose is required or not.