Vaccine efficacy and duration of protection

Are COVID-19 vaccines effective against Omicron subvariant BA.2?

COVID-19 vaccines likely offer strong protection against symptomatic disease caused by the fast-spreading Omicron subvariant BA.2.

According to recent data from the UK [^1], vaccine effectiveness against symptomatic disease was similar for BA.1 and BA.2 sublineages of Omicron; and vaccines offered 70% (58-79%) protection against symptomatic COVID-19 caused by BA.2 two weeks after the booster dose.



  1. UK Health and Security Agency. COVID-19 vaccine surveillance report. Week 4. 27 January 2022. Available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1050721/Vaccine-surveillance-report-week-4.pdf