A study by Pune-based National Institute of Virology (NIV) on 18 people, who inadvertently received both Covishield and Covaxin doses in Uttar Pradhesh’s Siddharth Nagar shows that a combination of vaccines elicit better immunogenicity than two doses of the same vaccine, either Covishield or Covaxin. The study was conducted by ICMR-National Institute of Virology Pune and is yet to be peer-reviewed.
The immunization program against Covid-19 in India began in January this year with two vaccines- AstraZeneca ChAdOx1-nCov-19 (known as Covishield in India) and inactivated whole virion BBV152 (Covaxin) and the traditional or homologous prime-boost approach was followed since.
However, in May this year, in a goof-up by health workers in UP’s Siddharthnagar, a group of villagers were administered Covaxin after being were given Covishield as the first shot.
A Study by NIA Pune compared the safety and immunogenicity profile of the individuals against those who received either Covishield or Covaxin (n=40 in each group).
Lower and similar adverse events following immunization were seen in the combination vaccine regime.
“Immunogenicity profile against Alpha, Beta and Delta variants in heterologous or (mix and match) group was superior; IgG antibody and neutralising antibody response of the participants was also significantly higher compared to that in the homologous groups,” the study revealed.
The finding also suggests that immunization with a combination of two different platforms- an adenovirus vector platform-based vaccine (Covishield) followed by an inactivated whole virus vaccine (Covaxin) was not only safe but also elicited better immunogenicity.
On June 29, the Subject Expert Committee of the Central Drugs Standard Control Organisation (CDSCO) had recommended mixing vaccine doses. The SEC has recommended that permission be granted to Christian Medical College (CMC), Vellore, for conducting a clinical trial on the mixing of Covaxin and Covishield.