The amount was pledged as Prime Minister Narendra Modi addressed the virtual Global Vaccine Summit hosted by British Prime Minister Boris Johnson in which over 50 countries - business leaders, UN agencies, civil society, government ministers, heads of state and country leaders participated.
In his address, Modi said India stands in solidarity with the world in these challenging times, according to a statement from the PMO.
He said the COVID-19 pandemic, in someways, has "exposed the limitations of global cooperation and that for the first time in recent history, the human kind faces a clear common enemy".
Referring to Gavi, he said it is not just a global alliance but also a symbol of global solidarity and a reminder that by helping others we can also help ourselves, according to the statement.
Modi said India has a vast population and limited health facilities and that it understands the importance of immunisation.
India's civilisation teaches to see the world as one family and that during this pandemic it had tried to live up to this teaching.
He said India did it so by sharing the country's available stocks of medicines with over 120 countries, by forging a common response strategy in its immediate neighbourhood.
Modi said New Delhi also provided specific support to countries that sought it, while also protecting India's own vast population.
He said one of the first programmes launched by his government was Mission Indradhanush, which aims to ensure full vaccination of the country's children and pregnant women, including those in the remote parts of the vast nation.
He said in order to expand protection, India has added six new vaccines to its National Immunization Programme.
The prime minister elaborated that India had digitized its entire vaccine supply line and developed an electronic vaccine intelligence network to monitor the integrity of its cold chain.
These innovations are ensuring the availability of safe and potent vaccines in the right quantities at the right time till the last mile, he said.
India is also the world's foremost producer of vaccines and that it is fortunate to contribute to the immunization of about 60 per cent of the world's children, he pointed out.
Modi said India recognises and values the work of Gavi, that is why it became a donor to Gavi while still being eligible for Gavi support.
He said India's support to Gavi is not only financial. India's huge demand also brings down the global price of vaccines for all, saving almost USD 400 million for GAVI over the past five years.
He reiterated that India stands in solidarity with the world along with its proven capacity to produce quality medicines and vaccines at low cost.
India not only has the capacity to contribute to the global health efforts, but also has the will to do so in a spirit of sharing and caring, the prime minister noted.
Gavi, the Vaccine Alliance, helps vaccinate half the world's children against deadly and debilitating diseases, according to its Twitter handle.
In a tweet, the alliance thanked Modi and the people of India for pledging USD 15 million. NAB ZMN