CAMBRIDGE (CBS) – Cambridge biotech company Moderna says it’s ready to move into the second phase of its development of a potential coronavirus vaccine.

Moderna has been testing healthy adult volunteers with three doses of the vaccine.

Those results are not available yet, but the company has now asked the Food and Drug Administration to move onto phase two which involves two vaccinations and studying those volunteers for a year.

Depending on the previous results, phase three could begin in the fall.

Moderna Therapeutics lab in Norwood. (Image credit: CBS News)

Public health officials have said it could take 18 months to fully validate a vaccine.