The U.S. government says it will begin phase III clinical trials of Corona19 vaccines next month with three private pharmaceutical companies.

Anthony Pouch, director of the National Allergy and Epidemic Research Institute, said he will start phase 3 clinical trials with Moder next month, Oxford-AstraZeneca in August, and Johnson & Johnson in September.

The phase 3 trial targets tens of thousands of people and is the final stage of verification before being marketed for new drugs.

"The vaccine development effort is progressing well and we expect at least one candidate to be in an advanced clinical trial phase in the early summer," said Pouch.