U.S. volunteer receives first shot of experimental coronavirus vaccine

A healthy U.S. volunteer received the first dose of an experimental coronavirus vaccine, a potential defense against the virus if it becomes a long-term threat.

Where it stands: The trial will ultimately give 45 volunteers two doses about 28 days apart in order to test the vaccine's effectiveness in protecting the subjects against COVID-19. If successful, several more trials with larger subject groups will be needed to prove whether there are common side effects.

Context: The vaccine candidate, code-named mRNA-1273, was developed by the National Institutes of Health and Massachusetts-based biotechnology company Moderna Inc.

Several other vaccines from researchers and companies around the world are in development.

What to watch: Even if the trial is successful, a vaccine for mass production and distribution worldwide will likely not be available for 12–18 months, said Anthony Fauci, director of the NIH's National Institute of Allergy and Infectious Diseases.