On May 4, local time, WHO Director-General Tedros Adhanom Ghebreyesus said at a press conference that the number of cases reported in the Americas and Africa was increasing due to the Omicron subtype strain.

South Africa has now reported two Omicron subtype strains, BA.4 and BA.5, following the report of the Omicron strain at the end of last year, which has contributed to the surge in cases in South Africa.

Tedros also said it was too early to determine whether these new subtype strains caused more severe disease than other Omicron subtype strains.

But early data suggest that vaccination is still protective against severe illness and death.

(produced by Le Xiaomin)

Responsible editor: [Luo Pan]