Neutralization of Beta and Delta variant with sera of COVID-19 recovered cases and vaccinees of inactivated COVID-19 vaccine BBV152/Covaxin

Abstract

In the last several months, several SARS-CoV-2 variants have emerged from various countries worldwide.1 Among them, variant of concern (VOC) i.e. Alpha (B.1.1.7), Beta (B.1.351), Gamma (B.1.1.28.1) and Delta (B.1.617.2) are serious public health threats because of their association with the higher transmissibility and the potential immune escape.1,2 Various reports have been published on the neutralization efficacies with the sera of the currently available COVID-19 vaccines against these variants.1,2 However, the immune escape of Beta variant has been serious concern for the COVID-19 vaccination programme. It has shown reduced neutralization to several approved vaccines such as mRNA-1273, BNT162b2, ChAdOx1 nCoV-19, NVX-CoV2373.1 Another reason of global concern is the recent emergence and detection of highly transmissible Delta variant from India and various other countries.2 An inactivated SARS-CoV-2 vaccine, BBV152/Covaxin was rolled out under the national COVID-19 vaccination programme in India. The neutralization potential of the BBV152 has been already studied with the B.1, Alpha, Zeta and Kappa found to be effective against these variants.3–5