Neutralization of Variant under Investigation B.1.617.1 with Sera of BBV152 Vaccinees

To the Editor—The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants in places where the virus is uncontained poses a global threat from the perspective of public health and vaccine efficacy. Peng et al [1] recently reported on the increased transmissibility with the newly emerged Variant of Concern (VOC) (20C/S:452R and 20C/S:452R) with the L452R mutation in San Francisco. We report the immunological characteristics of a Variant under Investigation (VUI) B.1.617.1, playing a critical role in the current surge of coronavirus disease 2019 (COVID-19) in the western state of Maharashtra, India. Several SARS-CoV-2 variants—B.1.1.7, B.1.351, and B.1.1.28.1—have been reported in India during 2021 [2, 3]. We had sequenced 146 nasopharyngeal/oropharyngeal swabs of COVID-19 cases [4]. Among these, 15 sequences had a combination of L452R and E484Q mutations, which raised concern as both are found in the receptor-binding domain (RBD) of the spike protein. However, the combined effect of these mutations is still unknown.