The multi-billion-dollar effort to get a coronavirus vaccine on the market could see delays because researchers haven’t recruited sufficient numbers of minorities to join the clinical trials.

Of the 350,000 people who’ve registered online for a coronavirus clinical trial, 10% are Black or Latino, according to Dr. Jim Kublin, executive director of operations for the Covid-19 Prevention Network.

That’s not nearly enough, as study subjects in trials are supposed to reflect the population that’s affected. Research shows that more than half of US coronavirus cases have been among Black and Latino people.

Dr. Francis Collins, director of the National Institutes of Health, gave the Moderna trial, the first in Phase 3 in the United States, a “C” grade for recruiting minorities.

“From the first week I saw the numbers, and they were not as encouraging as I would have liked,” Collins told CNN.

The stakes are high. Operation Warp Speed, the government’s effort to develop a coronavirus vaccine, says it aims to deliver 300 million doses by January — a speed unheard of in the history of vaccine clinical trials.

If not enough Black people and other minorities enroll, the panel of experts who monitor the trials could force a delay until they get the numbers they need.

“That’s something that’s been actively discussed,” said Dr. Nelson Michael, coordinator of community engagement activities for Operation Warp Speed. “There’s a lot of concern.”

Michael said several factors have led to “a perfect storm of not goodness” for recruiting Black study subjects: historical abuse of Black people in medical experiments like Tuskegee; present racial injustices and health care disparities; and recent social unrest and the financial strain placed on the Black community by the faltering economy.

Black leaders agree that it’s a challenge to recruit Black people into the vaccine trials, especially since it needs to happen very quickly — the first two Phase 3 clinical trials started in late July and expect to finish enrollment in September.

“This is a very, very tall order,” said Dr. James Powell, a Cincinnati physician who has been approached with requests to encourage Black participation in the vaccine trials.

“When we Black people hear ‘clinical trials,’ we think ‘we’re not going to be researched on,’ and that’s across economic status and across educational status, not just one sector,” said Renee Mahaffey Harris, president of The Center for Closing the Health Gap in Cincinnati.

Moderna and Pfizer, the two US companies currently in Phase 3 trials, won’t reveal how many of their participants are from minority groups. Each trial eventually expects to recruit 30,000 participants.

Moderna’s 89 trial sites across the United States are “actively working within their local communities to reach a diverse population of volunteers,” Ray Jordan, a company spokesman, wrote in an email. “We hope to achieve a shared goal that the participants in the (Covid-19 vaccine) study are representative of the communities at highest risk for COVID-19 and of our diverse society.”

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-CNN