India, Feb. 2 -- The study, published in Nature Microbiology, examined viral evolution in eight Omicron variants to better understand how the virus has reacted since the introduction of vaccinations1. It found that earlier Omicron variants such as BA.1 lost mechanisms to overcome innate immunity, but that later variants regained this ability, suggesting a common evolutionary strategy that has implications for pathogen surveillance.

Since the beginning of the COVID-19 pandemic, new variants of concern emerged independently from the first wave SARS-CoV-2 virus. Alpha, Delta and then Omicron in turn became the dominant variants in circulation.

Previous work showed that Alpha and Delta evolved to overcome human innate immunity, our first li...