Will Novavax's (NVAX 2.06%) NVX-CoV2373 be the next coronavirus vaccine to win major regulatory approval? Its prospects look good after the company's release of two sets of clinical trial data on Thursday.

The first, drawn from a phase 3 study in the U.K., indicate that the vaccine candidate was 96.4% efficacious against mild, moderate, and severe COVID-19 caused by the original strain of the coronavirus. Against the so-called "U.K. variant," which is apparently far more transmissible, NVX-CoV2373's efficacy was 86.3%.

The second is from a phase 2b clinical trial that took place in South Africa, where the "South African" variant of the coronavirus is rampant. The vaccine was found to be 55.4% efficacious in HIV-negative participants receiving inoculation.

Child getting a jab from a medical professional.

Image source: Getty Images.

Novavax added that, in both studies, NVX-CoV2373 demonstrated 100% protection against severe COVID-19 and prevented all hospitalization and death. The vaccine was well-tolerated and produced low levels of severe, serious, and medically attended adverse events.

The news comes as those variants continue to spread in certain geographies. Also, while vaccine rollout in many countries is gathering pace, complete inoculations are still in the single digits in many nations. One of these is the U.S., which, according to data compiled by The New York Times, hasn't quite reached 10% of the population yet.

While anxious observers might be concerned that the efficacy of the Novavax vaccine against the South African variant could be higher, it's still good by traditional vaccine measures at over 55% efficacy. As such, assuming it's approved by major regulators like the U.S. Food and Drug Administration, it should be an effective new weapon in the fight against the coronavirus.