The head of the World Health Organization Director-General Tedros Ghebreyesus is calling for rich countries with large supplies of coronavirus vaccines to refrain from offering booster shots through the end of the year.

The call by Ghebreyesus on Wednesday, was his second in a matter of months after an earlier request fell largely on deaf ears.

The WHO boss says he was “appalled” at comments by a leading association of pharmaceutical manufacturers on Tuesday, that vaccine supplies are high enough to allow for both booster shots and vaccination in countries in dire need of jabs but facing shortages.

Tedros told a news conference in Geneva, that he will not stay silent when companies and countries that control the global supply of vaccines think the world’s poor should be satisfied with leftovers.

Tedros had previously called for a “moratorium” on booster shots through the end of September.

But wealthy nations countries — including Israel, Britain, Denmark, France, Germany, Spain and the United States — have begun or are considering plans to offer third shots of two-dose vaccines to their vulnerable people such as the elderly or those with compromised immune systems.