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Fauci ‘cautiously optimistic’ about Moderna’s experimental coronavirus vaccine

In interviews on CNN and NPR, he said the results from an early-stage trial by the Cambridge biotech are ‘promising.’

Dr. Anthony Fauci at a Coronavirus Task Force news conference at the White House last month.Kevin Dietsch/Bloomberg

Dr. Anthony Fauci, the nation’s leading infectious disease expert, says he is encouraged by partial data from an early-stage trial of Moderna’s experimental coronavirus vaccine.

In a press release early Monday morning, the Cambridge biotech reported that eight participants in a study who received the experimental COVID-19 vaccine produced antibodies that killed the coronavirus.

While skeptics have noted that the results for other participants in the small trial have not yet been disclosed ― and that the company did not provide any data beyond what it cited in the press release ― Fauci said he was impressed.

“Although the numbers were limited, it was really quite good news because it reached and went over an important hurdle in the development of vaccines," he said during a CNN “town hall” Thursday evening. "That’s the reason why I’m cautiously optimistic about it.”


On NPR’s “Morning Edition” Friday, he delivered a similar message.

“It is really quite promising in the sense of that in the phase one study — which is the first step towards the development of a vaccine through its multiple phases ― the vaccine induced what we call neutralizing antibodies, as opposed to just binding antibodies," he said. "And neutralizing antibodies that actually can block the virus.”

He tempered his remarks on NPR by saying there could be “hiccups” and “landmines” that derail the progress of experimental vaccines being tested by Moderna and other companies and labs worldwide.

“There could be so many things that get in the way, like it might not be entirely effective,” said Fauci, who serves on the White House’s coronavirus task force and is the longtime director of the National Institute of Allergy and Infectious Diseases.

While saying that 12 to 18 months remains a reasonable timeline for a vaccine, he added, “It is conceivable that if we don’t run into things that are ... unanticipated setbacks, that we could have a vaccine that we could be beginning to deploy at the end of this calendar year.”


Moderna’s stock price rose about 3.5 percent in midday trading on the Nasdaq exchange following Fauci’s comments. That followed a 10 percent drop on Thursday after investors digested criticism of the company’s reporting methods. The stock closed Friday at $69, up about 3 percent. Since the start of the year, however, Moderna’s stock has tripled in value.

Eight companies are testing COVID-19 vaccines in humans, but Moderna was the first to report any results.