Director-General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus speaks during a press conference on occasion of the Global Vaccination Summit in Brussels, Belgium, Sept. 12, 2019. (Photos: Xinhua)

Director-General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus speaks during a press conference on occasion of the Global Vaccination Summit in Brussels, Belgium, Sept. 12, 2019.

Director-General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus speaks during a press conference on occasion of the Global Vaccination Summit in Brussels, Belgium, Sept. 12, 2019.

Director-General of the World Health Organization (WHO) Tedros Adhanom Ghebreyesus speaks during a press conference on occasion of the Global Vaccination Summit in Brussels, Belgium, Sept. 12, 2019.