An early-stage trial of a coronavirus vaccine appears promising – but it’s not time to pop out the champagne quite yet.

The announcement from biotech company Moderna amounted to a status update on how the first phase of its clinical trials are going. Some participants in the small, initial trial developed virus-fighting antibodies similar to those found in patients who have recovered from covid-19, suggesting the vaccine triggers a level of immunity. That’s good news, certainly, but far from the large-scale trial needed before a vaccine can be approved.

But medical professionals are under increasing pressure to produce results from President Donald Trump, who yesterday announced he is taking the anti-malarial drug hydroxycholoroquine – which has not proven to help prevent or treat the novel coronavirus – after two people inside the White House recently tested positive for covid-19. Trump last week announced a goal of “hundreds of millions” of vaccines against coronavirus for Americans by the end of 2020, which conflicts with the 12 to 18 month timeline offered by public health officials.

The stock market jumped for joy Monday after Moderna’s announcement. Shares in the Massachusetts company surged nearly 20 percent at its news. That news, combined with positive comments from Federal Reserve Chair Jerome Powell and the loosening of state shutdowns, delivered a “triple whammy” for Wall Street investors after two weeks of market volatility, my colleague Taylor Telford reports.

In a normal course of vaccine development, researchers would typically wait until all of the results are in before drawing conclusions. But because of heavy pressure to produce a vaccine in months instead of years during this pandemic, the company is moving forward more quickly than usual because it believes the initial results look sufficiently promising.

In the study, which began in March, 45 participants ages 18 to 55 were given three different dose levels of the vaccine. It’s typical for phase one clinical trials, which are intended to test the safety of a vaccine before it’s given to more people, to include fewer than 100 participants. Researchers are still collecting data about how the other 37 participants fared and will likely report that information once it’s assembled.


“We are very, very happy because first the vaccine was generally safe,” Stephane Bancel, chief executive of Moderna, told my Washington Post colleague Carolyn Y. Johnson. “The piece that was really exciting and was the big question, of course, was can you find antibodies in people in enough quantities” to prevent disease.

The Food and Drug Administration has given Moderna permission to begin a 600-person, phase two clinical trial next month. And in July, the company hopes to take on its biggest hurdle: a much larger, phase three trial that will determine whether regulators rule the vaccine is safe and effective for the public.

The vaccine Moderna is working on is one of 14 promising candidates identified by the National Institutes of Health, working in conjunction with biopharmaceutical companies. The vaccines are being put through the usual phases of clinical trials, with typical numbers of participants in each.

The difference under the accelerated timeframe is researchers won’t have time to study the length of time over which the vaccines are effective – that is, whether they protect people from the coronavirus for one year, three years or more.

“What is being cut out here is the time to study the long-term effects of the vaccine on those individuals,” said Esther Krofah, executive director of FasterCures, a center of the Santa Barbara, California-based Milken Institute.

Vaccine trials and the government approval process can take a decade or more from start to finish. Phase one trials for the shingles vaccine Shingrix started in 2005. The FDA didn’t approve the drug until 2017. That gave researchers much more time to build a broad base of knowledge about how it works.


“You will typically have the long enough time frame to be able to answer those questions with clarity, and that’s what we’re losing the midst of all of this,” Krofah told me.

People want to know the virus – whose death toll in the United States is approaching 90,000 – can be defeated sometime in the near future. Even as states reopen their economies, there’s a broad consensus life won’t return to normal until there’s a way to protect people through a vaccine, a process that typically takes years.

Trump has fueled such hopes for breakneck vaccine development, promising his Operation Warp Speed initiative will produce results by the end of the year – even as infectious-diseases chief Anthony Fauci has suggested such a short timeline is unrealistic.

“Vaccine experts have said that these accelerated development timelines are theoretically possible, but extremely optimistic – and depend on everything going right,” Carolyn writes. “They stress that it will be crucial to gather convincing data the vaccines are safe and effective before using them broadly – and the new data are promising but preliminary, from the earliest phase one trials that test safety in healthy people.”

“I would certainly take this as good news, and it’s certainly worth moving forward” into later stage trials, Daniel Salmon, director of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health, told her. “There’s just historically, if you look at vaccine development, lots of vaccines that look good out of phase one that don’t turn out to be good products.”