First detection of SARS‐CoV‐2 Omicron BA.4 variant in Western Pennsylvania, United States

At the time of writing, the world continues to witness the extraordinarily rapid evolution and selection of SARS-CoV-2, with the Omicron variants comprising five lineages known as BA.1, BA.2, BA.3, BA.4 and BA.5. In this study, there were 141 SARS-CoV-2 positive nasopharyngeal specimens tested using the RT-PCR BA.1 assay during January-April 2022. Of these, 83.0% specimens were BA.1. While the prevalence rate of BA.1 continued to decrease, BA.2 emerged. Interestingly, BA.4 was detected for the first time in Western Pennsylvania, United States. While the unexpected detection of BA.4 in our study is interesting, and even a single case, our finding underscores the importance of genomic surveillance as a critical tool for tracking emerging variants of SARS-CoV-2 This article is protected by copyright. All rights reserved.