May 12, 2020 3:20 PM EDT

On May 12, Moderna Therapeutics, based in Cambridge, Mass., received fast-track approval from the U.S. Food and Drug Administration (FDA) for its COVID-19 vaccine candidate, mRNA-1273. Days earlier, the FDA gave the company the green light to proceed to Phase 2 testing of the vaccine, which is expected to begin shortly. The company plans to launch the final stage of human testing, Phase 3, this summer, assuming the Phase 2 studies are complete, says Dr. Stephen Hoge, president of Moderna.

Fast-track designation boils down to a more expedited review process by the FDA. In particular, it means the agency can review data on a rolling basis so an entire application for approval isn’t held up until the final piece of data is collected and analyzed. “It’s validation that the FDA believes this is a very credible exercise,” says Hoge.

The Phase 2 studies will include around 600 healthy volunteers, half of whom are 18-55 years old and half of whom are over 55 years old. They will be randomly assigned to receive either placebo or one of two doses of Moderna’s experimental vaccine. Each participant will receive two shots—early studies suggest two injections might be necessary to jump-start the immune system to generate protection against the COVID-19 virus. All the patients will then be followed for a year as the researchers monitor their immune responses.

Already, Moderna is thinking ahead towards the next steps should its vaccine receive FDA approval. “We have not hit major speed bumps or road blocks, so it’s been good so far,” says Hoge of developing and testing the vaccine. “But now as the data develops, we need to show that we can manufacture at scale, and we’re doing all we can to scale up to supply tens of millions of doses by the end of this year.”

Moderna’s vaccine relies on a relatively new technology based on the mRNA of the virus; it involves injecting fragments of the viral genetic material into the body, which then stimulates the body’s immune system to fight the novel coronavirus.

Public health experts anticipate that the COVID-19 virus won’t dissipate any time soon, and believe that generating strong and widespread immunity to the virus, with the help of vaccines, will be essential in keeping the disease under control and reopening economies around the world. Currently, there are around eight vaccines being tested in people, using different technologies. Public health experts believe that multiple vaccines may be needed in order to meet global demand to immunize and protect as many people as possible from COVID-19 in coming years.

Contact us at editors@time.com.

Read More From TIME

Related Stories

EDIT POST