GENEVA- The World Health Organization is in advanced negotiations with Pfizer about including the company's COVID-19 vaccine in the agency's portfolio of shots to be shared with poorer countries, a senior WHO official said on Monday.

"We are in very detailed discussions with Pfizer. We believe very soon we will have access to that product," Bruce Aylward, a senior adviser, said at the WHO's executive board meeting.

The WHO's vaccine-sharing scheme COVAX is set to start rolling out vaccines to poor and middle income countries in February.

(Reporting by Emma Farge and Stephanie Nebehay Editing by Gareth Jones) ((emma.farge@thomsonreuters.com;))