New Omicron subvariants BA.4 and BA.5 appear to escape antibody responses among both people who had previous COVID-19 infection and those who have been fully vaccinated and boosted, according to new data from researchers at Beth Israel Deaconess Medical Center, of Harvard Medical School.

However, COVID-19 vaccination is still expected to provide substantial protection against severe disease, and vaccine makers are working on updated shots that might elicit a stronger immune response against the variants.

BA.4 and BA.5 caused an estimated 35% of new COVID-19 infections in the United States last week, up from 29% the week before, according to data shared by the US Centers for Disease Control and Prevention on Tuesday.

BA.4 and BA.5 are the fastest spreading variants reported to date, and they are expected to dominate COVID-19 transmission in the United States, United Kingdom and the rest of Europe within the next few weeks, according to the European Centre for Disease Prevention and Control.