Indian healthcare workers have shown high immune response to Covid after receiving the two mandated doses of both domestically manufactured vaccines —Covishield and Covaxin.
Covishield triggered more antibodies than Covaxin, claims a preprint of the first Indian study involving doctors and nurses who received both doses of either of the two Covid-19 vaccines. The study by Dr AK Singh and his colleagues states that both vaccines elicited a good immune response.
“Among 515 healthcare workers (305 male, 210 female), 95% showed seropositivity (higher antibodies) after two doses of both vaccines. Of the 425 Covishield and 90 Covaxin recipients, 98.1% and 80%, respectively, showed seropositivity. However, both seropositivity rate and average rise in anti-spike antibody was significantly higher in Covishield versus Covaxin recipients,” the study authors show.
The study highlights the significance of speedy vaccination to avert a potential third wave of the pandemic, signalling the urgency of expanding the coverage, which is running low due to stock shortages of Covaxin and Covishield.
While no difference was observed in relation to gender, body mass index, blood group and any comorbidities, people aged 60 years and above or those with type 2 diabetes had a significantly lower seropositivity rate, indicating a comparatively lower antibody response. The study also shows a good safety profile for both vaccines.
The study published by a group of doctors – Awadhesh Kumar Singh, Sanjeev Ratnakar Phatak, Ritu Singh, Kingshuk Bhattacharjee, Nagendra Kumar Singh, Arvind Gupta, and Arvind Sharma – has not been peer-reviewed yet. The researchers have declared no competing interest and that no funding was received for this cross-sectional study.
The study was aimed at analysing the antibody response after two complete doses of Covishield and Covaxin in Indians.
“We assessed the humoral immune response after the completion of two doses of both ChAdOx1-nCOV (Covishield) and BBV-152 (Covaxin) vaccines in Indian health care workers,” the authors said.
Due to the shortage, it’s easier for people to get a single dose rather than both doses — given that the recommended gap has been extended to as many as 12 weeks for Covishield.
For the study, 515 healthcare workers from 13 States and covering 22 cities were evaluated from January to May 2021. Their blood samples were also tested for the presence, quantity of antibodies produced and levels of the specific antibodies that are directed to the spike protein of the virus, widely held to be a proxy of protection.