World Health Organization chief Tedros Adhanom Ghebreyesus on Wednesday called on some advanced countries to suspend their ongoing or planned administration of third shots for the novel coronavirus until at least the end of September, saying fair access to COVID-19 vaccines among all countries is a higher priority.

Noting that many people must work to make a living even amid the pandemic, the WHO chief told a press conference, "While hundreds of millions of people are still waiting for their first dose, some rich countries are moving towards booster doses."

"We need an urgent reversal, from the majority of vaccines going to high-income countries, to the majority going to low-income countries," he said.

The WHO "is calling for a moratorium on boosters until at least the end of September, to enable at least 10 percent of the population of every country to be vaccinated," Tedros said.

His remarks come as some developed countries move ahead with booster shots to protect their populations as the highly contagious Delta variant rages in many countries, leading to surges in infection cases.

Israel's booster shots are in full swing for people aged 60 or older, while Germany and Sweden are scheduled to start providing third COVID shots for the elderly in the fall. Britain is also preparing to start offering booster shots in September.