Safety and Immunogenicity of Mix-Match of Vaccines -Covishield and Covaxin – a Pilot Study

Abstract

This single-center prospective observational study was conducted to assess the safety and immunogenicity of combination vaccines AstraZeneca’s ChAdOx1-nCov-19 (Covishield in India) and inactivated whole virion BBV152 (Covaxin). A total of 330 unvaccinated healthy volunteers were screened for SARS-COV2 seropositivity. RT PCR tests were conducted for seronegative volunteers (n =44). They were randomly assigned to four groups and given either same or mixed vaccines at an interval of 4 weeks between the two doses. Mix and match of vaccines did not evoke any adverse events. Combination of vaccines elicited similar immune responses in 4 groups. They were further studied dividing into homologous and heterologous vaccine groups. In Conclusion, Combination vaccines are safe and immunogenic and heterologous vaccines elicit better immunogenic response.

Heterologous Booster Dose with CORBEVAX following Primary Vaccination with COVISHIELD Enhances Protection against SARS-CoV-2

“…While all three vaccines were shown to evoke immune responses, we in a pilot study Ref. [16] and others from different parts of the world have reported combinations of vaccines to induce greater immunogenicity [22][23][24]. Our study corroborates with other studies showing durable humoral and cellular immune responses in individuals who were administered heterologous booster (Ad26.COV2.S) after two doses of mRNA vaccine (BNT162b2) compared to homologous booster vaccine [22,25].…”

“…While all three vaccines were shown to evoke immune responses, we in a pilot study Ref. [16] and others from different parts of the world have reported combinations of vaccines to induce greater immunogenicity [22][23][24]. Our…”

“…We had conducted a pilot study to assess the safety and immunogenicity of a combination of vaccines with Covishield and Covaxin in the primary vaccination regimen. It was observed that a combination of vaccines elicited greater immune responses [16]. A higher immunogenicity was observed in individuals who received a heterologous booster compared to a homologous booster, with similar reactogenicity and adverse events.…”