The coronavirus is killing Hispanic, Black and American Indian children at much higher numbers than their White peers, according to federal statistics released Tuesday.

The numbers — the most comprehensive U.S. accounting to date of pediatric infections and fatalities — show there have been 391,814 known cases and 121 deaths among people under the age of 21 from February to July.

Of those killed by covid-19, the illness caused by the coronavirus, more than 75 percent have been Hispanic, Black and American Indian children, even though they represent 41 percent of the U.S. population, according to the Centers for Disease Control and Prevention. The federal agency collected data from health departments throughout the country.

The disproportionate deaths among youths echo pandemic disparities well-documented among adults. Previous studies have found the virus’s death toll is twice as high among people of color under age 65 as for White Americans. People of color also disproportionately make up “excess deaths” — those killed by the virus without being diagnosed or those killed indirectly by the virus’s wide effects on the health-care system.

The racial disparities among children are in some ways even more stark.

Of the children and teens killed, 45 percent were Hispanic, 29 Black and 4 percent American Indian.

“This is the strongest evidence yet that there are deep racial disparities in children just like there are in adults,” said John Williams, chief of pediatric infectious diseases at UPMC Children’s Hospital of Pittsburgh. “What that should mean for people is steps like wearing a mask are not just about protecting your family and yourself. It is about racial equity.”

One key factor could be underlying health disparities among minority children and young adults. About 75 percent of those who died had at least one underlying condition, and the most frequent were asthma and obesity — two conditions that disproportionately occur in minority youths.

“On one hand, the small total number of deaths is reassuring. You’re talking about hundreds of thousands of children infected, and only 121 killed,” said Frank Esper, a pediatric infectious-disease specialist at Cleveland Clinic Children’s. “At the same time, proportions at which minority groups are dying are hard to ignore.”

The CDC report pointed to underlying social disparities that minority children are more likely to experience than their White peers: crowded living conditions, food and housing insecurity, parents who are essential workers and cannot work from home, wealth and education gaps and difficulty accessing health care because of a lack of family resources including insurance, child care, transportation or sick leave.

In the report, CDC officials conclude that what’s needed is for health departments, medical providers and communities to “mobilize to remove systemic barriers that contribute to health disparities.”

In addition to social disparities, the racial gap in fatalities suggests genetic or biologic factors could be at play, said Williams. Some diseases have been shown to affect certain races more severely. Before a vaccine was developed, for example, pneumococcal meningitis disproportionately affected Black children, Williams said, even after accounting for social determinants. Similarly, Haemophilus influenzae type b (also known as Hib) was known to disproportionately affect Native Americans.

The CDC report emphasized that the relatively low death toll for children was recorded when almost all schools were closed, and that it is unknown how the reopening of schools could affect those rates.

Tuesday’s CDC report reinforced another prominent characteristic of the virus — that it becomes increasingly lethal with age. Among children, only 10 percent of deaths occurred in infants age 1 or younger. Roughly 20 percent of pediatric cases were between ages 1 and 9. The remaining were between ages 10 and 20.

Since the virus emerged, the way it attacks the elderly and leaves the very young relatively unscathed has been a central and puzzling mystery to scientists. In that regard, the novel coronavirus behaves differently from other viruses, such as seasonal influenza. Those other viruses are especially dangerous for the very young and very old.

Figuring out why children are less affected, researchers believed, could help them understand how and why the virus sickens and kills other age groups. While there are not yet definitive answers, emerging evidence suggests a key protein — called the ACE2 receptor, which the coronavirus uses to enter cells — is present in lower amount in the airways of children than in adults.