Review of pre-Omicron data finds COVID-19 vaccine protection from severe disease remains strong at six months

An analysis of research literature published last year before the Omicron variant took hold found that while COVID-19 vaccines lose some effectiveness in preventing SARS-CoV-2 infection, the vaccines retain nearly all of their ability to prevent severe disease up to six months after full vaccination. The study, which appears online February 21 in The Lancet, was led by researchers at the Johns Hopkins Bloomberg School of Public Health and the World Health Organization.