Dr. Fauci says he's 'cautiously optimistic' about COVID-19 vaccine trials

• On Monday, pharmaceutical company Moderna announced encouraging results from its first human trial of a potential coronavirus vaccine.
• "The question is: Was it immediately safe? Clearly it was," Dr. Anthony Fauci said of the prospective vaccine. "But, importantly, it induced the kind of response that you would predict would be protective against the virus."
• Several companies are working to develop a preventative solution for the coronavirus. On Thursday, the US government agreed to pay British pharmaceutical giant AstraZeneca up to $1.2 billion to secure 300 million doses of its experimental vaccine.

Researchers developing a vaccine for the novel coronavirus have already achieved a milestone that has eluded colleagues working for decades on a vaccine for HIV, Dr. Anthony Fauci said Thursday.

Earlier this week, the biotech company Moderna, which has partnered with the National Institutes of Health, announced early findings from the first phase of trials for a COVID-19 vaccine, which was tested on 45 human volunteers.

The early results were encouraging: eight of those in the trial developed a specific type of antibody (a neutralizing antibody) that is associated with stopping the virus from infecting people. (As Fauci said, neutralizing antibodies bind to the "business end of the virus and block its ability to infect.")

While acknowledging that vaccine development is still in early stages, Fauci, director of the National Institute on Allergy and Infectious Disease, noted to CNN that this result was not a given — and "that's why I'm cautiously optimistic about it."

"The question is: Was it immediately safe? Clearly, it was," Fauci said of the prospective vaccine. "But, importantly, it induced the kind of response that you would predict would be protective against the virus."

"It was really quite good news," he added.

Several companies are working to develop a preventative solution for the coronavirus. On Thursday, the US government agreed to pay British pharmaceutical giant AstraZeneca up to $1.2 billion to secure 300 million doses of its experimental vaccine.

The company began a trial of the drug in April involving 1,000 healthy volunteers, according to Reuters. Results are expected soon.

The US has struck a similar deal with Moderna, as well as Johnson & Johnson, and French pharmaceutical company Sanofi.