The Global Alliance for Vaccines and Immunization said Monday (July 12) that it had signed two advance purchase agreements with Chinese drugmakers Sinopharm and Sinovac to provide up to 550 million COVID-19 vaccines to the COVAX program.
The new deals include up to 170 million doses of the Sinopharm shot, and up to 380 million shots of the Sinovac vaccine, through to the middle of 2022.
GAVI, which runs the global vaccine sharing scheme COVAX with the World Health Organization, did not immediately provide details of which countries would receive the doses.
Chief executive Seth Berkley said deliveries can start quickly because both vaccines have already been granted emergency use listing by the WHO.
Thailand and Indonesia, which used Sinovac as a first dose, are switching to other shots for the second dose to increase protection against COVID-19.
GAVI did not immediately respond to a request for comment about whether it had concerns about the vaccine's efficacy.
The WHO said on June 1, when it approved Sinovac's shot, that results showed it prevented symptomatic disease in 51% of those vaccinated, and prevented hospitalization in 100% of the studied population.
The Sinopharm vaccine has an estimated efficacy of 79% for all age groups, the WHO said in early May, when it approved the shot.