Despite making up just 13% of the population, Black people account for more than 40% of new HIV diagnoses in the United States. But what makes some Black folks more vulnerable to HIV than others?

Social vulnerability may play a role, according to new data published in Morbidity and Mortality Weekly Report. “Social vulnerability” is government jargon for the factors that make it hard for a community to bounce back from a natural disaster or public health threat—for example, low income, limited transportation and overcrowded or inadequate housing.

Researchers with the Centers for Disease Control and Prevention (CDC) looked at where the 13,807 Black folks diagnosed with HIV in 2018 lived. Using the CDC’s Social Vulnerability Index, they found that 75% of the Black people who acquired HIV lived in communities with the highest or second highest social vulnerability. Only 8% came from the least vulnerable communities.

Overall, Black people who lived in communities with the highest social vulnerability were 1.5 times more likely to acquire HIV than those in the least socially vulnerable neighborhoods. What’s more, same-gender-loving Black men who use drugs were 11.6 times more likely to acquire HIV if they lived in highly vulnerable communities. For cisgender women, the pattern was similar: Overall, Black women were 1.8 times more likely to acquire HIV if they lived in the highest-vulnerability areas.

“HIV disparities are not inevitable and can be addressed,” says the head of the CDC’s HIV Prevention Program, Demetre Daskalakis, MD. “Our nation must finally tear down the wall of factors—systemic racism, homophobia, transphobia, HIV-related stigma and other ingrained barriers—that still obstructs these tools against HIV and COVID-19 from equitably reaching the people who could benefit from them.”