Shortly before 7 Monday morning, a woman at a Savannah, Ga., clinic held out her arm to receive an injection — and so kicked off a nationwide study that has stirred high hopes for a bulwark against COVID-19 even as the disease claims 1,000 American lives a day.
The volunteer, identified in news reports as WTOC television anchor Dawn Baker, is the first participant in the first late-stage clinical trial of a potential coronavirus vaccine in the United States. Dr. Anthony Fauci, the nation’s top infectious diseases doctor, called the study’s launch a “truly historic event.”
The study aims to enroll 30,000 people — including hundreds from New England — to test a vaccine candidate developed by Cambridge-based Moderna Inc. and the National Institute of Allergy and Infectious Diseases, which Fauci heads.
Brigham and Women’s Hospital in Boston is among the 87 study sites and the only one in New England. The hospital expects to start administering the shots later this week.
Researchers may have interim results by November or earlier, but it’s impossible to predict with certainty, Fauci said.
The Moderna vaccine employs a genetic technology never before used in a medication. In an early-phase trial, the vaccine candidate triggered the production of antibodies — immune-system proteins that attack intruders in the body — in all 45 volunteers, and their antibodies killed the virus in the laboratory.
Now, researchers want to give the experimental vaccine to large numbers of people and see whether they are less likely to catch the coronavirus than a similar group receiving a placebo.
Such a study is called a Phase 3 clinical trial. The Moderna vaccine is one of five candidate vaccines that have advanced to this stage around the world, but the first one in the United States.
Fauci said Moderna and NIAID had set a record by beginning Phase 3 about six months after Chinese scientists shared the genetic sequence for the novel coronavirus that causes COVD-19.
Dr. Francis Collins, director of the National Institutes of Health, said researchers “now have a chance to find out in the real world” whether Moderna’s vaccine is effective against the coronavirus.
About a dozen sites are expected to begin enrollments this week, said Ray Jordan, a Moderna spokesman. More than 50 sites are expected to be participating by next week, and most of the remaining sites by the following week.
Participants will receive either the vaccine candidate or the placebo in two injections 28 days apart.
The study is recruiting people who are at risk of exposure to the virus, such as those living in high-density housing, or who are working in occupations involving many interactions with people, said Dr. Lindsey R. Baden, an infectious diseases specialist at Brigham and Women’s who is one of three principal investigators in the national study as well as the leader of the New England site.
The study also aims to enroll those at greater risk of severe illness if they become infected, such as people with heart or lung disease or diabetes, Baden said. Researchers hope to find out whether the vaccine can prevent severe illness in those who do get infected, he said.
But the most important question is whether the vaccine is safe, he said.
“Nothing about this is compromising safety,” Baden told the Globe. “There is no shortcut on safety.”
That point was repeatedly emphasized in a telephone news conference Monday from the National Institutes of Health in Bethesda, Md., with Fauci, Collins, and others.
“We have focused on speed because every day matters,” said Moderna CEO Stéphane Bancel. “We are losing people every day around the world.” But, he added, “We are doing it without compromising safety.”
In addition to receiving two injections of the experimental vaccine, participants will undergo six or seven blood draws, and researchers will be in frequent touch by telephone, Baden said. They plan to follow patients for up to two years after administering the drug.
Anyone who develops symptoms, such as a cold or flu-like sickness, will undergo a COVID-19 test. People who don’t feel ill won’t be tested for COVID-19 during the study, but blood tests will look for evidence of antibodies against the coronavirus, to detect asymptomatic infections.
Researchers also will be watching closely for side effects, especially in the first few days after the injection. In the earlier study, one-third of the patients suffered short-lived side effects that included fatigue, chills, headache, muscle pain, or pain at the site of injection.
“I want to get away from the concept that ‘safe’ means you never have a side effect,” Baden said. “We have to make sure the benefit . . . outweighs any risk.” Many people who get the shingles vaccination, for example, feel ill for a couple of days afterward, but consider that preferable to getting shingles.
Anyone interested in participating in the study can fill out a questionnaire at https://rally.partners.org/study/covid_vax.
In addition to online registries, recruitment will involve advertising in social and print media and reaching out directly to “communities not often engaged in research,” Baden said, particularly people of color, who have been disproportionately affected by the virus. “We want to make sure we have people from underrepresented communities,” he said.
The vaccine will be deemed effective if it prevents at least 60 percent of infections, which Fauci said is a standard threshold.
“Obviously, we would like to see much, much higher, but 60 percent is the cutoff,” Fauci said at the news conference.
Combined with public health measures such as social distancing and mask-wearing, Fauci said, a vaccine that is 60 percent effective would still have a powerful impact on the pandemic.
If the vaccine works, it likely wouldn’t be rolled out until next year. But Bancel, the Moderna CEO, said at the news conference that the company might seek emergency authorization from the Food and Drug Administration to make the vaccine available earlier for a “subset of the population.”
Moderna’s experimental vaccine is one of several that have received hundreds of millions of dollars from the federal government under the Trump administration’s program called Operation Warp Speed.
The others include a collaboration between Johnson & Johnson and Beth Israel Deaconess Hospital, a collaboration between AstraZeneca and the University of Oxford, and one by Novavax, a Gaithersburg, Md., biotech. None is as far along in clinical trials in the United States as the Moderna vaccine.
If the vaccine is successful, it would be a significant validation of the genetic technology that Moderna was founded a decade ago to develop. So far, the company has not brought a single product to market.
Moderna’s technology deploys a molecule known as messenger RNA, or mRNA, a strand of genetic material that enters cells and provides the blueprint for making the proteins that cells need to function. To create a vaccine against the coronavirus, Moderna scientists programmed the mRNA to prompt the cell to manufacture a piece of the coronavirus. This triggers an immune response that theoretically will spring into action and destroy the virus if a person is infected.
On Monday, Moderna’s stock climbed as much as 11 percent as the trial started, on the heels of news that the federal Biomedical Advanced Research and Development Authority had pledged up to $472 million more for the study, in addition to the $483 million it had already provided. The stock ended the day up 9.1 percent.