Dr. Anthony Fauci (R), director of the National Institute of Allergy and Infectious Diseases, will attend the Coronavirus Task Force's daily briefing at the White House in Washington, DC on April 22, 2020.
Drew Angerer | Getty Images
The White House Coronavirus Advisor, Dr. Anthony Fauci said Monday he was "not particularly concerned" about the safety risk of a potential Moderna coronavirus vaccine, despite using new technology to fight the virus.
The vaccine, which entered a large human phase 3 trial on Monday, uses messenger ribonucleic acid or mRNA molecules to elicit an immune response to fight the virus. Scientists hope that mRNA, which passes on genetic instructions from DNA, can be used to train the immune system to recognize and destroy the virus. While early studies are promising, mRNA technology has never been used to make a successful vaccine.
"It is a novel technology. We are certainly aware that there is not as much experience with this type of platform as with other standards," Fauci, director of the National Institute for Allergy and Infectious Diseases, told reporters on a conference call alongside the director of the National Institutes of Health, Dr. Francis Collins.
"I'm not particularly worried," said Fauci. "But I don't want a lack of serious concern to make us open to looking for possible harmful effects as we go in and through the Phase Three study."
Scientists may know if a potential Moderna coronavirus vaccine will work in October, but is likely to achieve full results by November, Fauci said.
Moderna, who works in partnership with the NIH, announced earlier in the day that it had started late in its vaccine trial. According to ClinicalTrials.gov, the study will involve at least 30,000 participants in at least 87 locations. Trial arm participants received a dose of 100 micrograms of the potential vaccine on the first day and a further 29 days later. Some patients receive a placebo.
If approved by the Food and Drug Administration, Moderna's experimental vaccine would be the first of its kind. Researchers will follow participants for a year after the phase three study to monitor the potential safety risks of the vaccine, and two years, to monitor its effectiveness, said Fauci.
Fauci hopes the vaccine will be at least 60% effective, which means that the vaccine lowers the risk of Covid-19 infection by an average of 60%. "Of course we would like to see it much, much higher. But 60% is the standard you do for the cutoff. It is not uncommon," he said. "I would like to see the highest percentage we could get."
Fauci cited the potential vaccine as a major achievement and said the time it took from the virus' genetic sequence to a phase three trial was a record for the United States.
Fauci's comments came days after he said that a coronavirus vaccine would probably not be "widely available" to the American public until "several months" in 2021.
Public health officials and scientists expect to know if at least one of the many potential Covid-19 vaccines under development is safe and effective by late December or early next year, he said during a live Q&A with the Washington Post on Friday.
"It is likely that we will have tens of millions of doses available early next year," said Fauci, adding that some drug companies have predicted more doses. "I think if we arrived a few months later in 2021, you would have vaccines that are widely available."
Although scientists believe an effective vaccine will be available by next year, there is no guarantee. While drug manufacturers are running to produce millions of vaccine doses, there is a possibility that the vaccine will need two doses instead of one, which may further limit the number of people who can be vaccinated once a vaccine is available, experts say.
Moderna said it was still on the right track to deliver between 500 million and 1 billion cans a year from next year.