AstraZeneca expects to be able to deliver a billion doses of a possible Covid-19 vaccine this year and next if tests are successful, adding today that it should shortly get results of an early stage clinical trial.
The British drugmaker said it had signed the first agreements to supply at least 400 million doses of the vaccine, which it is developing with Oxford University.
It 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.
Only a handful of the vaccines in development have advanced to human trials, an indicator of safety and efficacy, and the stage at which most fail.
There are currently no approved treatments or vaccines for Covid-19 being tested by pharmaceutical giants across the world.
Governments, drugmakers and researchers are working on around 100 programmes and experts predicting a safe and effective means of preventing the disease could take 12 to 18 months to develop.
AstraZeneca also said in a statement that it had received more than $1 billion from the US Biomedical Advanced Research and Development Authority for development, production and delivery of the potential vaccine.
It said the Covid-19 vaccine it was testing would include a planned late-stage clinical trial with 30,000 participants and a paediatric trial, adding that it planned to start supplying the vaccine in Britain in September.
Other drugmakers including Pfizer, Johnson & Johnson and Sanofi are also in various stages of vaccine development.
US-based Inovio Pharmaceuticals said this week that its experimental vaccine produced protective antibodies and immune system responses in mice and guinea pigs.
And Moderna also this week released positive data for its potential vaccine, which it said produced protective antibodies in a small group of healthy volunteers.
AstraZeneca said it was engaging with international bodies, including the World Health Organization, for the fair allocation and distribution of the potential vaccine around the world.