US pharmaceutical company Novavax said on Monday that its COVID-19 vaccine has an overall efficacy of 90.4% against the coronavirus.

The company said its two-dose vaccine demonstrated 100% protection against moderate and severe disease, based on a study that included 29,960 participants across 119 sites in the US.

Against some coronavirus variants, which represented 82% of the cases, the vaccine efficacy was 93.2%, it added.

In a statement, the president of Novavax’s Research and Development Gregory M. Glenn said that data showed consistent and high levels of efficacy, which reaffirm the ability of the vaccine to prevent COVID-19 amid ongoing genetic evolution of the virus.

Novavax joins other American pharmaceuticals — Pfizer-BioNTech, Moderna, and Johnson & Johnson — that provide vaccines for the US population.

More than 374 million doses have been distributed in the US with over 309 million administered as of early Sunday. So far, 143.9 million people, or 43.4% of the population, have received two doses, according to figures from the US Centers for Disease Control and Prevention (CDC).