Pfizer Inc could have a COVID-19 vaccine available in the world's largest economy by the end of 2020.
The drugmakers hope to get to the initial target figure of 30,000 participants for the vaccine trial.
Moderna has already begun experimental testing on humans.
WHO has been working to expand access to potential vaccines and scale up production capacity.
UK now has 3 different types of vaccine under development with a total of 230 million doses.
BioNTech is in partnership with Pfizer to develop a coronavirus vaccine.
The news that a potentially successful COVID-19 vaccine was underway raised global investors’ optimism.
The results encouraged moving to a larger clinical trial to test if the vaccine is actually safe.