arthralgia or cough was reported the pyrexia was of low to moderate grade and was managed by administration of paracetamol and subsided in all participants within three to four days post vaccination according to the studydespite the high median age of the participants of the heterologous group 62 years in our study the reactogenicity profile demonstrated that mixing of the two vaccines based on different platforms is safe the study saidthe study demonstrates that immunisation with a heterologous combination of an adenovirus vector platformbased vaccine followed by an inactivated whole virus vaccine is safe and elicits better immunogenicity than two doses of homologous vaccination using the same vaccinesthese findings have an important implication for the covid19 vaccination programme wherein heterologous immunisation will pave the way for induction of improved and better protection against the variant strains of sarscov2such mixed regimens will also help to overcome the challenges of shortfall of particular vaccines and remove hesitancy around vaccines in peoples mind that could have genesis in programmatic errors especially in settings where multiple covid19 vaccines are being used the study highlightedhowever to conclusively prove these findings a multicentre rct needs to be carried out the study also underlinedearlier recommendationsan expert panel of the drugs controller general of india had in july recommended a study on mixing doses of covaxin and covishield vaccinesthe subject expert committee of the central drugs standard control organisation cdsco had also recommended granting permission for trials of mixing covaxin and covishield as per sourceswith inputs from pti