WHO Director General Says Vaccine Effectiveness Against Omicron Variants, Highlights Booster Dose Problems

Illustration: WHO. (Wikimedia Commons/United States Mission Geneva)

JAKARTA - The effectiveness of the COVID-19 vaccine appears to be reduced in preventing severe illness and death, but provides significant protection, the World Health Organization (WHO) said Tuesday.

The Omicron variant, which was first detected in South Africa and Hong Kong last month, has now been reported by 77 countries and is probably present in most of the world, should not be considered "mild", WHO Director-General Tedros Adhanom Ghebreyesus said.

"The Omicron variant is spreading at a rate we haven't seen with any variant before," Tedros said in an online briefing, citing Reuters December 15.

"Even if the Omicron variant does cause less severe disease, the sheer number of cases could once again overwhelm an unprepared health system."

"Growing evidence suggests a small decrease in the effectiveness of the vaccine against severe illness and death and a decrease in preventing mild illness or infection," he said without providing details.

Pfizer-BioNTech's COVID-19 vaccine has been less effective in South Africa in keeping people infected with the virus out of hospital since the Omicron variant emerged last month, a real-world study published on Tuesday showed.

Meanwhile, Mike Ryan, the WHO's director of emergencies, said vaccines did not fail and provided significant protection against severe illness and death.

"The question is, how much protection are we currently using, which is currently saving lives against all variants, and to what extent are we losing protection against severe disease and death against Omicron. The data point to that being a significant protection."

Ryan said the peak of this wave of infections was still "a few weeks" away given the very rapid spread of the Omicron variant, which has outpaced the global dominant Delta strain.

Meanwhile, booster doses of the vaccine could play a role in limiting the spread of COVID-19 as long as the people most in need of protection also have access to injections, Tedros said.

"This is a matter of priority. The order is important. Giving boosters to groups with a low risk of severe illness or death only endangers the lives of those at high risk who are still waiting for their main dose due to supply constraints," Tedros said.

"On the other hand, giving additional doses to people at high risk can save more lives than giving the main dose to those at low risk," he said.

Tedros noted that the emergence of Omicron has prompted several countries to launch COVID-19 booster programs for their entire adult populations, although researchers have no evidence for the efficacy of boosters against this variant.

"WHO is concerned that such a program will repeat the vaccine stockpiles we saw this year and exacerbate injustice."