COVID-19 vaccines appear to have become slightly less effective in preventing severe disease and death but do provide "significant protection", the World Health Organization (WHO) said on Tuesday.
The Omicron variant first detected in South Africa and Hong Kong last month has now been reported by 77 countries and is probably present in most worldwide, but should not be dismissed as "mild", WHO Director-General Tedros Adhanom Ghebreyesus said.
"Omicron is spreading at a rate we have not seen with any previous variant," Tedros told an online briefing. "Even if Omicron does cause less severe disease, the sheer number of cases could once again overwhelm unprepared health systems."
"Evolving evidence suggests a small decline in the effectiveness of vaccines against severe disease and death, and a decline in preventing mild disease or infection," Reutters cited him as saying.
Vaccine booster shots can play a role in curbing the spread of COVID-19 as long as people most in need of protection also get access to jabs, Tedros said.
