What happened

Shares of Moderna (MRNA 1.69%) jumped 8.3% on Thursday after the biotech said it has dosed the first participants in a study evaluating its new coronavirus booster-vaccine candidates. 

So what 

Moderna's COVID-19 vaccine is believed to offer some protection against all of the most common coronavirus variants, including the strains first identified in the U.K. and South Africa. Yet the biotech is testing whether a booster dose could provide even more protection, particularly to people who are more vulnerable to severe forms of the disease.

A person in safety gear is holding a vial labeled coronavirus 2019.

Moderna's stock price rose sharply on Thursday on optimism for its booster vaccines. Image source: Getty Images.

To do so, it will provide a single booster dose to 60 participants in its ongoing phase 2 study who have already been vaccinated with its COVID-19 vaccine, mRNA-1273. Some participants will receive a variant-specific booster candidate targeted at the South African strain, while others will receive a dose that combines the booster with Moderna's previously authorized vaccine.

Now what

Should the booster vaccines prove safe and provide an additional layer of protection against coronavirus variants, they could become an important weapon in the global battle against COVID-19. In the process, they would also give Moderna a significant new source of recurring revenue, particularly if the booster shots are needed on an annual basis or every six months.