What happened

Shares of Moderna (MRNA 3.39%) surged 10.5% Wednesday after the National Institutes of Health (NIH) began testing the drugmaker's experimental COVID-19 variant vaccine. 

So what

Moderna's new vaccine is designed to protect against a coronavirus strain first identified in South Africa. The worrisome mutation -- which scientists warn could spread faster than earlier versions of the virus and be more resistant to currently authorized vaccines  -- has been detected in at least nine states in the U.S. 

The NIH's phase 1 study will evaluate the drug's efficacy and safety profile among 210 healthy adult volunteers. These participants will include 60 people who took part in Moderna's original coronavirus vaccine trial, as well as 150 people who have not yet been vaccinated. The NIH expects the study to be fully enrolled by the end of April.

A person is pointing to a digital stock chart that rises, then falls, then rises again.

Investors bid up Moderna's stock Wednesday. Image source: Getty Images.

"Preliminary data show that the COVID-19 vaccines currently available in the United States should provide an adequate degree of protection against SARS-CoV-2 variants," National Institute of Allergy and Infectious Diseases (NIAID) Director Anthony Fauci said in a press release. "However, out of an abundance of caution, NIAID has continued its partnership with Moderna to evaluate this variant vaccine candidate should there be a need for an updated vaccine."

Now what

The U.S. Food and Drug Administration (FDA) is expected to accelerate the emergency authorization process for vaccines that defend against coronavirus variants. So, if it proves safe and effective, Moderna could bring its new COVID-19 vaccine to market relatively quickly. 

Moderna will likely have more to say to investors about its clinical trials during its upcoming virtual Vaccines Day event on April 14.