The COVID-19 virus is not stagnant, instead the virus has undergone various variants since its initial spotting back in late 2019. From widely known strains like Omicron and Delta to more recent lesser known strains like BA2.5, the virus has continued to evolve and change as the pandemic continues. Below, there is a chart that shows major variants that are found within the US as well as comparing some of their differences in symptoms, transmission levels, vaccine efficacy and more. Check out the Major US Variants document below.