Moderna emerged as an early leader in the race for a vaccine to stop Covid-19 in its tracks. The Cambridge, Massachusetts-based biotech bounded through development of one of the world’s first mRNA vaccines, but in September — when the pandemic was claiming upwards of 700 lives a day in the US — they took a step back.

The company did something not many (if any) biotechs have ever done: At the urging of the US government, they slowed Phase III enrollment to recruit more participants from minority groups.

Unnamed sources told Reuters that site investigators had quickly filled “a large portion” of the nearly 30,000-person study with white volunteers. But in mid-September, Black Americans made up only about 7% of Moderna’s COVE study, even though they are about three times as likely to be hospitalized with Covid and almost twice as likely to die.

Those figures look bad for Moderna, but they’re par for the course in biopharma, where minority groups have historically been left out of clinical trials. Of the 53 drugs approved this past year, Black patients represented about 8% of participants in the trials regulators based their decisions on (and for which data on race was collected). To put that in perspective, Black Americans represent about 13% of the US population. That lack of representation isn’t a mistake, some experts say.

“The way in which biomedical research works is contaminated by structural racism,” NIH director Francis Collins said at a Milken Institute event earlier this month.

After slowing their trial, Moderna ended up reporting results from just over 10,000 participants from communities of color, according to FDA documents. Black participants made up 9.7% of the overall trial population, and Hispanic or Latinx patients represented 20%. American Indian and Alaskan Native volunteers comprised 0.8% — while non-Hispanic white patients made up 63.3%.