The candidate vaccines, including those from AstraZeneca and Novavax, will be priced at $3 per dose and will be made available in 92 countries in GAVI's COVAX Advance Market Commitment (AMC), the company said in a statement.
The Gates Foundation will provide the funds to GAVI, which will be used to support Serum Institute.
GAVI, backed by the Gates Foundation, is a public-private global health partnership with the goal of increasing access to immunization in poor countries.
It co-leads COVAX - a scheme designed to guarantee fast and equitable access globally to COVID-19 vaccines - along with the World Health Organization and the Coalition for Epidemic Preparedness Innovations (CEPI).
COVAX aims to deliver 2 billion doses of approved and effective COVID-19 vaccines by the end of 2021.
India reported a record jump in daily coronavirus infections on Friday and became the third country in the world to surpass 2 million cases. It lags only the United States and Brazil in the number of infections.
(Reporting by Anuron Kumar Mitra in Bengaluru; Editing by Ramakrishnan M. and Anil D'Silva)