As omicron and its sub-variants continue to spread globally, there may be some benefit to delivering a second dose of a coronavirus booster vaccine to the most vulnerable, an expert group convened by the World Health Organization said. In a statement Tuesday, the United Nations health agency said that there is growing evidence of the value of additional booster doses for health workers, people over 60 and those with weakened immune systems.

The WHO said its expert group assessed limited data from seven studies of booster-dose second messenger RNA vaccines, saying there was insufficient information to prove they would be effective in young, healthy people. The WHO said that additional boosters of the mRNA vaccine may be needed for those most at risk of becoming seriously ill or dying, acknowledging that there may be logistical or other challenges in getting people to receive a second booster in some countries. While many rich countries have vaccinated more than 70% of their populations, less than 16% of people in poorer countries have been vaccinated.

Last year, the WHO repeatedly criticised rich countries for providing boosters and called for a moratorium on the practice, saying healthy people don’t need boosters. Late last year, the agency withdrew its recommendation due to the spread of a highly contagious variant of the omicron after dozens of countries began offering booster doses.
Some health experts have warned that countries starting additional booster vaccinations could deplete the global supply of COVID-19 vaccines before the most vulnerable populations in developing countries are vaccinated.

In March, the USFDA recommended that Americans 50 and older be eligible for a second COVID-19 booster shot, while the European Medicines Agency has only approved a second booster shot for those 80 and older. Amid the continued spread of omicron and its sub-variants, WHO and others call for accelerated vaccination campaigns.

Maria Van Kerkhove, WHO’s head of COVID-19, said: “We found that vaccinated people had a much lower risk of serious illness and death, so be careful not to mistake omicron for mild. We have solutions because We have a vaccine,” she said.