(Reuters) – Britain’s AstraZeneca will be able to deliver 2 billion doses of its potential coronavirus vaccine this year and next, double the previous numbers, thanks to deals with the Serum Institute of India and two Bill Gates-backed global health organisations.

The company, which has already agreed to supply 400 million doses to the United States and British governments, said on Thursday it had agreed terms with the Indian company, the world’s largest manufacturer of vaccines by volume, to supply one billion doses for low and middle-income countries.

AstraZeneca’s partnership with Oxford University has garnered international attention as one of the leading coronavirus vaccine candidates, sealing more than $1 billion in U.S. government funding last month as it ramps up testing of the vaccine and manufacturing capacity.

It said it had also signed an agreement worth $750 million with the Coalition for Epidemic Preparedness Innovations (CEPI) and GAVI vaccines alliance, both founded by Microsoft-founder Gates and his wife, to produce 300 million doses of the vaccine.

GAVI said on Thursday it had raised $2 billion from international donors for an Advanced Market Commitment to buy future COVID-19 vaccines for poor countries, including a $100 million commitment from the Bill & Melinda Gates Foundation