According to a study published in Frontiers in Medicine, a peer-reviewed open-access medical journal, Omicron, a variant of SARS-CoV-2, can evade the immunity provided by vaccines. The study undertaken by the ICMR’s Regional Medical Research Centre (ICMR-RMRC), Gorakhpur, and the maximum containment facility of the National Institute of Virology (ICMR-NIV), Pune, emphasized the need to explore the Omicron variant’s immune evasion properties, which may be essential in planning for vaccine advocacy in the future in India.

For the study, whole genome sequencing (WGS) was conducted on 146 SARS-CoV-2 samples obtained from individuals who tested positive for coronavirus disease 2019 (COVID-19) between January 1, 2022, and February 24, 2022, in three districts of eastern Uttar Pradesh.

The study, titled "Omicron BA.2 lineage predominance in severe acute respiratory syndrome coronavirus 2 positive cases during the third wave in North India," showed that in the eastern Uttar Pradesh region, the Omicron BA.2 variant was out-competing the BA.1 variant predominantly.

When compared to the previously conducted Chennai study and Delhi study, the number of fully vaccinated individuals having the Omicron infection (a breakthrough infection) was higher. The current study confirmed that breakthrough infection was higher among healthcare workers as reported in previous studies. Further, the study highlighted that the median duration of contracting the COVID infection was around 6 months after the second dose of the vaccine.