A study conducted by the Indian Council of Medical Research (ICMR) has noted that mixing the COVID-19 vaccines, Covishield and Covaxin, may yield a better immune response, compared to a same-dose schedule.

The research suggests that in spite of a weakened antibody response after six months, individuals who received one dose of Covishield and a second dose of Covaxin six weeks apart (heterologous group) mounted a better immune response than individuals in the homologous group – people who received either Covishield or Covaxin as both doses.

The research body assessed people in a village in Uttar Pradesh who were accidentally given Covishield as the first dose and Covaxin as the second shot. The researchers assessed their immune responses over a 6-month period after the completion of the vaccination schedule. Two other groups were also included in the study — those who had received two doses of either Covaxin or Covishield.

There was a significant reduction in the IgG antibody titers, which target the receptor binding domain of the spike protein, in all the three groups. However, the heterologous group still had higher IgG antibody titers compared to the other groups, stated additional director-general of ICMR, Dr Samiran Panda… (ET Healthworld – TNN, March 9, 2022)