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12/20/2020

Race to a Coronavirus Vaccine

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. On the morning of November 11th, Moderna announced that it had hit that threshold. A few days later, the Data and Safety Monitoring Board held a call with Moderna’s management and N.I.H. officials, telling them that, of ninety-five confirmed cases of covid-19 among trial participants, ninety were in the placebo group. Eleven volunteers had developed severe cases; all of them were in the placebo group. The vaccine was nearly ninety-five per cent effective. Pfizer, working with the Germany-based immunotherapy company BioNTech, was performing similar trials on its own vaccine, with forty-two thousand volunteers. A week earlier, Pfizer had released preliminary data showing that its vaccine was ninety per cent effective. Both companies still had to finish their trials, but the announcements were exciting. Medical experts, including the top doctors at both Pfizer and Moderna, had been hoping that the vaccines would be seventy to eighty per cent effective. “Something like ninety-five per cent was really aspirational,” Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, at the N.I.H., said. “Well, our aspirations have been met. And that is really very good news.” The two companies achieved these results in less than four months, an unprecedented pace, without any serious side effects. “It is difficult to convey to those outside the field how extraordinary this achievement has been,” Kathleen Neuzil, who is co-leading the federal network that designs and oversees coronavirus-vaccine trials, told me. “The science and manufacturing allowed these vaccines to be developed in weeks, not years.” Pfizer and Moderna have since applied to the F.D.A. for emergency-use authorization, which could allow the first doses to be shipped out before the end of the year. On the evening after Honeycutt got her shot, she signed into an app on her phone to record her temperature and any symptoms. Her arm was sore. Otherwise, she felt unchanged. Both Moderna’s and Pfizer’s vaccines require two shots, roughly a month apart. After twenty-eight days, Honeycutt returned to the clinic for a second injection. The next morning, around nine o’clock, she started to get body aches and chills. Her temperature was slightly elevated, at 99.9 degrees. She bundled up and lay on the couch. By noon, her temperature was above a hundred. A few hours later, she felt better, she said, even excited: “I felt like I got the vaccine.” The vaccine that had possibly kick-started Honeycutt’s immune system relies on a recent innovation. By now, just about everyone has seen images of the infamous spike protein, which the coronavirus sars-CoV-2 uses to fuse to our cells, like a key in a lock. Traditional vaccines inject bits of weakened or inactivated virus, but Moderna’s and Pfizer’s coronavirus vaccines contain the molecular instructions—the mRNA—for making a replica of the sars-CoV-2 spike. When injected into our body, the mRNA orders our cells to start producing spike proteins. Our immune system recognizes these new spike proteins as antigens, foreign invaders, and creates antibodies to neutralize them. Then, if the actual sars-CoV-2 virus tries to breach our cells, our body will be prepared. A crucial development has allowed Pfizer and Moderna to move quickly. The spike protein alters its form once it fuses with a cell in our body; after the lock is opened, the key changes shape. In order for a vaccine to work, it has to present the body with the original key—the spike’s delicate, unaltered form—so that the immune system can learn how to keep the lock closed. Several years ago, Barney Graham, the deputy director of vaccine research at the National Institute of Allergy and Infectious Diseases, and Jason McLellan, a professor at the University of Texas, were investigating another coronavirus, Middle East respiratory syndrome (mers-CoV), in the hope of developing a vaccine. Earlier work on viruses suggested that, if they changed the genetic sequence slightly, the spike would retain its original shape. They tried two mutations on the mers spike protein, which worked, resulting in a potent vaccine. “It was a big moment when we realized that the idea was transferrable from one virus to another,” Graham told me. In 2017, the N.I.H. partnered with Moderna to see how rapidly they could develop an mRNA vaccine if there were a pandemic; they accelerated the effort in mid-2019. Not long afterward, a mysterious cluster of viral pneumonia cases appeared in the city of Wuhan, China, and their experiment suddenly became real. On January 10th, Chinese researchers published the sequence of the sars-CoV-2 genome. The next morning, Graham and his colleagues went to work developing a potential mRNA vaccine, using the stabilizing mutations from their research on mers. BioNTech, like Moderna, had been experimenting with mRNA vaccines. In late January, when Ugur Sahin, BioNTech’s co-founder, realized that sars-CoV-2 could cause a pandemic, the company began developing its own vaccine candidate. A few weeks later, Sahin called Kathrin Jansen, the head of vaccine research at Pfizer, and asked if her company would be interested in joining the effort. Jansen said that she had been planning to call him. The Moderna and Pfizer vaccines are more similar than different. In both, the mRNA is encapsulated in a substance called a lipid nanoparticle, a shell of precisely formulated fat, which helps carry the mRNA into our cells. Like nearly every vaccine in use today, they also both require two doses. (The flu shot is a single dose, but a new one is required every year.) The first dose exposes the immune system to the antigen, which creates a population of antibodies that can respond to it. The second dose expands that population. Anyone who catches the coronavirus between the first and second shots—a real risk in a pandemic—would likely have protection from severe disease, but no one knows yet the extent of that protection. Johnson & Johnson is currently testing a coronavirus vaccine, in a trial of sixty thousand people, that could work with just one shot. It might not provide durable protection, however, so in November the company started a second, global Phase III trial that will give two shots to as many as thirty thousand participants. Thirteen companies worldwide have made it into late-stage, large-scale clinical efficacy trials. Back in April, to coördinate and accelerate this sprawling vaccine-development effort, Peter Marks, the director of the Center for Biologics Evaluation and Research, at the F.D.A., proposed a moon-shot program that, as a longtime “Star Trek” fan, he dubbed Project Warp Speed. Marks now leads the F.D.A. team that will make the final call on granting emergency-use authorization to the leading vaccine candidates. Acknowledging the stakes, he recalled a line from James Bond, in which the head of M.I.6 says, “This is the big one, 007. Do not screw it up.” Moncef Slaoui, the former head of vaccine development at GlaxoSmithKline, was eventually appointed the head of what is now known as Operation Warp Speed. The program has so far provided at least twelve billion dollars to pharmaceutical companies for researching, developing, and manufacturing vaccines and drugs, with the biggest contracts awarded to Moderna, Sanofi (which is partnering with GlaxoSmithKline), Novavax, Johnson & Johnson, and AstraZeneca. All of them except AstraZeneca are using Graham and McLellan’s mutations. According to Graham, the original RNA technology came from Drew Weissman, a researcher at the University of Pennsylvania, whose work was also heavily funded by the N.I.H. “What do they say?” Graham said. “Success has many fathers, and failure is an orphan.” Pfizer and BioNTech decided not to accept funds from Operation Warp Speed. “I wanted to liberate our scientists from any bureaucracy,” Albert Bourla, the C.E.O. of Pfizer, said in an interview on CBS’s “Face the Nation.” BioNTech did receive four hundred and forty-five million dollars in funding from the German government, and the two companies signed a contract with Operation Warp Speed to sell their first hundred million doses to the U.S., at a cost of around two billion dollars. They also relied on Graham and McLellan’s publicly funded work when they created their vaccine’s mRNA sequence. In trials on mice and monkeys, as well as in Phase I trials on people, Pfizer and Moderna showed that their vaccines were safe and provoked robust immune responses. In May, companies and regulators began to suggest that a vaccine could be ready sooner than expected. “Once we started getting human data, then we really got more confident,” Graham said. Pfizer and Moderna began Phase III trials on July 27th. Waiting for enough volunteers to get sick—typically the most time-consuming aspect of a Phase III trial—was not likely to take long: covid-19 cases were surging around the country. The companies’ stock prices soared as executives sold off their shares. Donald Trump, too, tried to capitalize on the news. By summer, he was hyping the possibility that a vaccine could be ready before the election, although few public-health experts believed this timeline to be realistic. “You could have a very big surprise coming up,” Trump said in a press conference. “We’re going to have a vaccine very soon, maybe even before a very special date. You know what date I’m talking about.”

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