On a hot afternoon in August, Debbie Honeycutt walked into the crowded waiting room of the Medical Center for Clinical Research, an experimental-treatment facility tucked inside a squat office building in San Diego. She was volunteer number four hundred and ten out of four hundred and sixty-six that the clinic had recruited to test a potential coronavirus vaccine. After a brief screening, a research assistant led her into an exam room, where a doctor administered a nasal-swab test and performed a physical examination. Honeycutt, who is sixty-nine years old, with short white hair and a matter-of-fact disposition, spent much of her career as a fund-raiser in the fields of education and science. This would be her sixth time volunteering in a clinical trial, and it had never felt more important. In the seven months since the first cases of covid-19 had been identified in the United States, 5.6 million people had been infected and a hundred and seventy-five thousand had died. Honeycutt, who lives alone in a tranquil suburb of San Diego—“the kind of place where you know all your neighbors”—had seen friends fall gravely ill. She also knew that the study needed people from high-risk demographics: over sixty-five, with underlying health conditions. She had high blood pressure. “They need guinea pigs,” she said. “I believe in helping people.”

A nurse gave Honeycutt an injection. Neither of them knew whether the liquid was a placebo or an experimental vaccine known as mRNA-1273. Developed by the Massachusetts-based biotech company Moderna, the vaccine contains a microscopic chain of messenger RNA, the atom-size instructions for building proteins. No vaccine made from mRNA has ever been licensed for commercial use. After the injection, Honeycutt was kept under observation for thirty minutes, to be sure that it did not trigger an anaphylactic reaction; during that time, the vaccine, if that’s what she’d been given, was crossing her cell membranes, into the cytoplasm, where the ribosomes would begin using its code to manufacture a defense against the virus. Honeycutt hoped that she had got the real thing. But, she said, “you don’t know. It could be saline.”

Honeycutt was one of thirty thousand volunteers nationwide, aged eighteen and older, in Moderna’s Phase III trial—the final test of safety and efficacy before a company applies to the U.S. Food and Drug Administration for authorization. A Phase III clinical trial for an experimental vaccine is simple, at least in concept. Half the volunteers receive a placebo, and half receive the vaccine. No one can see who got what except the members of the Data and Safety Monitoring Board, an independent group of experts appointed by the National Institutes of Health. Once a predetermined number of volunteers develop symptomatic cases, the board members take their first peek at the data.

Read more