Breakthrough infections, which were caused subsequent to vaccination with COVAXIN and COVISHIELD have been caused by SARS CoV2 lineage B.1.617.2. The B.1.617.2 is a variant of concern (VoC). Clinicians at the AIIMS, New Delhi conducted a study based on the genomic analysis of vaccine breakthrough infections.

The B.1.617.2, first detected in India, and B.1.1.7, detected in Maharashtra were the variants of concern and considered to be responsible for the sudden uprising of cases during April-May 2021 in Delhi.

AIIMS collaborated with the CSIR Institute of Genomics and Integrative Biology (CSIR-IGIB) for the study 63 cases of vaccine breakthrough infections in Delhi were analysed. Of these, 36 patients were known to have received 2 doses, while the remaining 27 had received one dose of the vaccine.

53 patients were administered COVAXIN while 10 were administered COVISHIELD. The mean age of the sample size was 37 years, with the youngest being 21 and the eldest being 92. There were 41 males and 22 females and none had any co-morbidities, which could be identified as a predisposing factor for breakthrough infections.

The authors stated the uniqueness of the current report as this is one of the initial reports of symptomatic vaccine breakthrough infections and breakthrough infections caused in a tertiary care setting, which weren’t a part of the earliest reports of breakthrough infections with BBV152/Covaxin and B.1.617.2 variant of SARS-CoV-2.