Gavi, the Vaccine Alliance, has signed advance purchase agreements (APAs) with China's Sinopharm and Sinovac to provide up to 550 million Covid-19 vaccines to the COVAX programme immediately. The new deals include up to 170 million doses of the Sinopharm vaccine and up to 380 million shots of the Sinovac vaccine, until mid-2022, Gavi said in a statement Monday. "The agreements, which come at a time when the Delta variant is posing a rising risk to health systems, will begin to make 110 million doses immediately available to participants of the COVAX Facility, with options for additional doses," the statement read.  READ: Bangladesh hopeful of receiving 3.5 mln vaccine doses from COVAX this month: FM "This is yet another example of Gavi's active portfolio management strategy, ensuring the Facility has options in the face of constraints such as supply delays. Thanks to this deal, and because these vaccines have already received WHO Emergency Use Listing, we can move to start supplying doses to countries immediately," said Dr Seth Berkley, CEO of Gavi. The Sinopharm APA enables Q3 supply, with Gavi committing to purchase, on behalf of the COVAX Facility, 60 million doses that will be made available from July through October 2021. Also, Gavi has the option to purchase a further 60 million doses in Q4 2021 and 50 million more doses in the first half of 2022, if necessary. This equates to a potential total of 170 million doses of the Sinopharm vaccine that could be made available to self-financing participants of the Facility as well as participants supported by the Gavi COVAX advance market commitment (AMC). READ: COVAX: US welcomes shipment of 2.5mn vaccine doses to Bangladesh   The Sinovac APA also enables Q3 supply, with Gavi committing to purchase, on behalf of the COVAX Facility, 50 million doses to be made available from July through September 2021. Also, Gavi has the option to purchase a further 150 million doses in Q4 2021 and 180 million more doses in the first half of 2022. In total, up to 380 million potential doses of the Sinovac vaccine could be available to both self-financing participants of the Facility and those supported by the Gavi COVAX AMC. The COVAX Facility portfolio, administered by Gavi, currently consists of agreements related to 11 vaccines and vaccine candidates – AstraZeneca/Oxford, Clover, Johnson & Johnson, Moderna, Novavax, Pfizer-BioNTech, Sanofi/GSK, SII-Covishield, SII-Covovax, Sinopharm and Sinovac – providing participants access to a diverse range of vaccines suitable for use in varied contexts and settings and to mitigate against the risk of research and development failures, regulatory delays and supply constraints. READ: COVAX calls for equal recognition of all approved vaccines Gavi has recently published an updated Facility global supply forecast, which shows that thanks to several deals with manufacturers and donations from countries with excess supply, COVAX is on track to deliver more than 2 billion doses by early 2022. Of these, 1.8 billion fully donor-funded doses will be available for the 92 lower-income participants eligible for support by the Gavi COVAX AMC.