SARS-CoV-2 Omicron (BA.4, BA.5) variant: Lessons learned from a new variant during the COVID-19 pandemic

In late 2021, the world faced the rapid spread of the SARS-CoV-2 Omicron variant, which quickly became the variant of concern. In April 2022, two new lineages of Omicron (BA.4/BA.5) emerged from Africa, where they caused the fifth wave of infection.

We searched PubMed, Google Scholar, and Scopus online databases up to December 2023 for founding relevant studies.

BA.4 and BA.5 subgroups, with changes in the spike protein, have a greater ability to escape from the immune system, which was possible with the help of L452R and F486V mutations. Epidemiologically, these evolving subtypes show similarities to seasonal influenza but with higher mortality rates. The symptoms of these subgroups are different from the previous types in the form of upper respiratory symptoms. Antiviral treatments, the use of antibodies such as bebtelovimab, and the development of vaccines are promising.

Consequently, we must continue to be vigilant in our joint surveillance efforts against COVID-19 in diagnosis and treatment.