Moderna is accelerating an already exceptionally ambitious clinical development plan for its experimental coronavirus vaccine, announcing Thursday it expects to begin late-stage testing by this summer rather than its goal from just 10 days ago to start this fall. A Phase 1 study run by the National Institute of Allergy and Infectious Diseases is ongoing and could soon yield preliminary results. If the findings appear positive, Moderna will move quickly into a previously announced Phase 2 trial, the design of which the Food and Drug Administration cleared Wednesday. Moderna, which is backed by nearly half a billion dollars in funding from the U.S. government, has already begun ramping up production of its vaccine in anticipation of overwhelming demand, should it prove successful. Other companies developing coronavirus vaccines, such as Johnson & Johnson and Pfizer, are taking a similar approach.

Should Moderna’s plans unfold as the biotech’s executives now expect, late-stage testing could begin between three or four months after the first healthy volunteer received the company’s vaccine, and about six months after Moderna and government scientists designed the experimental treatment.

It’s an unprecedented timeline, reflecting both the deadly urgency of the coronavirus pandemic and the corresponding willingness by regulators to accept risks and trade-offs that would normally be unthinkable.

There’s no data yet on whether Moderna’s vaccine works to coax the body into producing protective antibodies against the SARS-CoV-2 virus. And by collapsing the typically years-long development timeline for vaccines, Moderna and NIAID will have substantially less information than usual on the treatment’s safety before late-stage testing begins.

Results from the Phase 1 trial being led by NIAID are due soon and will give a better sense of the vaccine, which relies on promising but as yet unproven technology. Forty-five healthy volunteers were quickly recruited into the first three study groups, and NIAID is now expanding with six additional cohorts of older and elderly adults.

But early data will likely only reveal whether Moderna’s vaccine is associated with any fast-emerging side effects, as well as whether dosing seems to elicit an immune response.

The Phase 1 study will also help inform which dose Moderna chooses to use for its Phase 3 trial.

On a Thursday call, Moderna executives gave few specifics on the design of that study, but did note that the company would be discussing with NIAID and with the Food and Drug Administration how many participants would be needed and how long they would need to be followed.

Moderna will be moving forward without its longtime financial chief, Lorence Kim, who is unexpectedly departing the company in August.

It’s a unusual time to be leaving a high-profile role, particularly as Moderna is in the world’s spotlight for its coronavirus work. Moderna has experienced notable executive exits in past years, although turnover is common among fast-moving biotechs.

Kim told analysts on the Thursday call that he will be “staying close to innovation in biotech,” but won’t be taking on a new position as a company executive.

Also on Thursday, Moderna announced three new senior vice presidents from Biogen, GlaxoSmithKline and Merck & Co. would be joining its infectious disease and regulatory teams.