AstraZeneca is partnering with University of Oxford to develop and distribute a vaccine being trialled in the UK.
AstraZeneca said it was capable of producing one billion doses of the AZD1222 vaccine this year and next.
Coronavirus (Covid-19) vaccine: The United States will pump up to $1.2 billion into developing AstraZeneca's potential COVID-19 vaccine and said on Thursday it would order 300 million doses, as the White House seeks solutions to the coronavirus pandemic. AstraZeneca said it recognised the vaccine might not work but if results from the early stage tests were positive, they would lead to late stage trials in several countries.
AstraZeneca said it was engaging with global bodies, including the World Health Organization (WHO), for the fair allocation and distribution of the potential vaccine around the world.
"AstraZeneca is also in discussions with governments around the world to increase access".
Concern has been growing over so-called vaccine nationalism - the prospect of drug makers receiving support from their own governments that enables the richest nations to develop the strongest inoculation regimes.
Pascal Soriot, Astra's chief executive, said: "This pandemic is a global tragedy and it is a challenge for all of humanity".
Under the deal with the United States government, its Biomedical Advanced Research and Development Authority (BARDA) will pay up to $1.2 billion to support advanced clinical studies and other development activities, including scaled-up manufacturing to speed up the roll out of the potential vaccine.
AstraZeneca said it was also working with worldwide distribution partners including the Serum Institute of India and promised that it would make the Oxford vaccine "widely accessible around the world in an equitable manner".
AstraZeneca said it has now finalised its licence agreement with Oxford University for the "recombinant adenovirus vaccine", which will now be known as AZD1222.
AstraZeneca said it had also agreed to support the establishment of a joint research centre at Oxford University for pandemic preparedness research.
However, AstraZeneca stressed that the vaccine may not work and that it was still waiting for results from an early-stage trial in southern England, before any moves towards late-stage testing.
The company said executives are aware the vaccine may not work but they're committed to progressing through more advanced trials while scaling up manufacturing, despite the risk.
Globally, the disease has infected more than 5 million people, with a death toll exceeding 329,000.
"Additionally, the company has quickly moved into testing of new and existing medicines to treat the infection, including the CALAVI and ACCORD trials underway for "Calquence", or acalabrutinib, and the DARE-19 trial for "Farxiga", or dapagliflozin, in Covid-19 patients".
France has slammed Paris-based drugs giant Sanofi for suggesting the U.S. would receive its vaccine first, as world leaders demand that the science should be shared among nations.