Moderna Inc says it has received an additional $472m from the United States government's Biomedical Advanced Research and Development Authority (BARDA) to support the development of its novel coronavirus vaccine.

The US-based drugmaker said on Sunday that the additional funding will support its late-stage clinical development including the expanded Phase 3 study of Moderna's vaccine candidate.

The company stands to make billions of dollars in sales if it is successful in developing a safe, effective vaccine.

In April, Moderna had received $483m from the US federal agency that funds disease-fighting technology, when the experimental vaccine was in an early-stage trial conducted by the US National Institutes of Health.

"Encouraged by the Phase 1 data, we believe that our mRNA vaccine may aid in addressing the COVID-19 pandemic and preventing future outbreaks," chief executive officer Stephane Bancel said in a news release.

BARDA's total funding for the experimental vaccine of Moderna, the first in the US to begin human trials of a coronavirus vaccine, is now about $955m.