World Health Organization (WHO) Director-General Tedros Adhanom Ghebreyesus. (FILE PHOTO)

World Health Organization chief Tedros Adhanom Ghebreyesus on Wednesday asked rich countries to suspend their ongoing or planned administration of boosted shots (third shots) against COVID-19 at least until the end of the year to ensure vaccine supplies for other countries.

Earlier, WHO director general had called for the suspension of the COVID-19 booster shots until the end of this month (September). But now he is seeking to extend the timeline for offering third shots, as the discrepancy in vaccine supply for poorer countries has yet to be overcome.

“A month ago, I called for a global moratorium on booster doses at least until the end of September, to prioritize vaccinating the most at-risk people around the world who are yet to receive their first dose,” Tedros told a press conference.

Noting that the situation has changed little since his earlier statement, Tedros said, “So today I am calling for an extension of the moratorium until at least the end of the year, to enable every country to vaccinate at least 40 percent of its population.”

Some developed countries are moving ahead with booster shots to protect their populations amid recent surges in infection cases, while developing countries have largely fallen behind in vaccination efforts against the novel coronavirus.

According to Tedros, while 5.5 billion doses of COVID-19 vaccine have been administered globally, 80 percent of them have gone to high and upper-middle income countries.

Booster shots are meant to strengthen vaccine efficacy, but the WHO takes a position of not recommending them under the present circumstances, citing a lack of sufficient data on efficacy and potential side effects with regard to the available coronavirus vaccines.

The WHO chief also urged advanced countries to “fulfill their dose-sharing pledges” to developing countries by the end of September.