Trial of Coronavirus Vaccine Made by Moderna Begins in Seattle

As bad as this epidemic is, Dr. Graham said, in one way it is lucky that a coronavirus caused it, because the researchers were at least partly ready for it. If another type of virus had caused the outbreak, it could have taken months longer to create a potential vaccine.

Other companies, using different approaches, are also trying to manufacture coronavirus vaccines. Moderna is the first to reach a clinical trial.

The trial will enroll 45 healthy adults ages 18 to 55. Each will receive two shots, 28 days apart. Moderna calls the vaccine mRNA-1273.

Three different doses will be tested — each in 15 people — and the participants will be studied to determine whether the vaccine is safe and whether it stimulates the immune system to make antibodies that can stop the virus from replicating and prevent the illness it causes.

Four participants were vaccinated on Monday, and four more are to get shots on Tuesday. Then there will be a pause to monitor them, before more participants receive injections, Dr. Graham said.

The participants will be followed for a year, but Stéphane Bancel, the chief executive of Moderna, said in an interview that safety data would be available a few weeks after the injections were given. If the vaccine then appears safe, he said, Moderna will ask the Food and Drug Administration for permission to move ahead to the next phase of testing even before the first stage is finished.

The second round of testing, to measure efficacy as well as to verify safety, will include many more participants.

Moderna, with headquarters in Cambridge, Mass., and a manufacturing plant in nearby Norwood, is already buying new equipment so that it will able to produce millions of doses. Bancel acknowledged that the company was taking a risk, because neither safety nor efficacy has been proved yet.

“Humans are suffering and time is of the essence,” he said. “Every day matters. We have taken these decisions to take the risk, because we believe it is the right thing to do.”

The company’s stock price jumped in February in response to news reports about the vaccine. And on Monday, Moderna’s stock rose more than 24 percent, rising $5.19 to close at $26.49.

Work on the vaccine started in January, as soon as Chinese scientists posted the genetic sequence of the new coronavirus on the internet. Researchers at Moderna and the National Institute of Allergy and Infectious Diseases identified part of the sequence that codes for a spike-like protein on the surface of the virus that attaches to human cells, helping the virus to invade them.

A nonprofit group, the Coalition for Epidemic Preparedness Innovations, helped pay to manufacture the vaccine for the trial.

That spike sequence is the basis for the vaccine. Moderna does not need the virus itself to produce its vaccine: The company synthesizes the stretch of RNA required for the vaccine and embeds it in a lipid nanoparticle.

By February 24, Moderna had a batch of vaccine ready to ship to the infectious diseases institute, for use in the trial. On March 4, the Food and Drug Administration gave permission for the trial to begin.