While gun violence has for years been among the leading causes of death for US children, the COVID-19 pandemic sent it skyrocketing to the top cause while widening racial disparities.

In the years before the pandemic—from 2015 to early 2020—Black children in four major US cities were 27 times more likely to be shot than white children. But, from 2020 to the end of 2021, Black children were 100 times more likely to be shot than white children, according to a new study in JAMA Network Open. The study examined firearm assault data from New York City, Los Angeles, Chicago, and Philadelphia.

The study also found that Hispanic children were about 26 times more likely to be shot than white children during the pandemic, up from a relative risk of 8.6-fold prior to the health emergency. And Asian children were about four times more likely to be shot than white children, up from a relative risk of 1.4-fold from before the pandemic.

While the rate of shootings among white children did not change during the pandemic, the health emergency was linked to a two-fold increase in firearm injuries among children overall. That equates to an extra 503.5 gunshot injuries than if the pandemic hadn't occurred, the study authors from Boston University estimated.

Firearm injuries have been on the rise for years prior to the pandemic. But in 2020, they became the top killer of US kids, surpassing car accidents and cancers. The increases have continued into 2021, according to the new analysis.

While the evidence is not clear as to why the pandemic spurred more firearm violence and racial disparity, the authors of the new study hypothesized community context plays a role.

"Our results are broadly consistent with research identifying sharper pandemic-associated violence increases in neighborhoods with less racial and economic privilege," the researchers wrote. "Possible explanations include COVID-19’s exacerbation of inequities in access to health, employment, and educational resources."

Following the school shooting at Robb Elementary in Uvalde, Texas, last year—which left 21 people dead, including 19 students between the ages of 7 and 10—medical associations renewed calls for common sense and evidence-based strategies to reduce firearm injuries and deaths in children. Those included universal background checks, banning people convicted of domestic violence from owning a gun, licensing laws, restrictions on carrying concealed firearms in public, gun safety education, and restrictions on assault weapons.

"As physicians, our mission is to heal and to maintain health. But too often the wounds we see in America today resemble the wounds I've seen in war," Gerald Harmon, president of the American Medical Association, said in a statement at the time. The AMA declared gun violence a public health crisis in 2016.

The American Academy of Pediatrics President Moira Szilagyi also pleaded for more to be done to address the public health crisis. "When will we as a nation stand up for all of these children? What, finally, will it take, for our leaders in government to do something meaningful to protect them?" she wrote in a statement. "The AAP has called on the federal government to increase funding for research into gun violence prevention and for common-sense laws that protect everyone in a community."

The authors of the new study also call for efforts to "target structural racism as a fundamental driver of the US firearm violence epidemic."