Brazil began offering a HIV prevention drug for free to at-risk populations in December, making it the first Latin American country to do so.
Truvada is a blue pill offered as part of a program known as PrEP, short for pre-exposure prophylaxis, The New York Times reports.
The CDC notes that when taken regularly, the drug -- which is a combination of anti-HIV drugs emtricitabine and tenofovir -- can reduce one's chance of contracting HIV by more than 90 percent, according to Reuters.
The Brazilian Health Ministry purchased the drug from American manufacturer Gilead Sciences at just a fraction of what U.S. citizens pay, The New York Times reports. Whereas a month of Truvada pills will set someone back $1,600 in the U.S., Brazil paid just 75 cents per dose.
The pill is available at no cost to eligible patients at 35 public health clinics across 22 cities. The program is still in its early phase and is expected to expand.
"Our hope is that with PrEP and other measures we can reduce the rate of new infections," said Adele Benzaken, the director of the Brazilian Health Ministry's AIDS department. "But it's a big challenge."
The prevalence of AIDS has exacerbated in Brazil in the past decade. Between 2006 and 2015, the number of men ages 15-19 with AIDS tripled to 6.9 cases per 100,000 citizens. In men ages 20-24, the number is 33.1 per 100,000.
U.N.AIDS, a UN agency that focuses on HIV prevention policy, said roughly 48,000 new cases of HIV were reported in Brazil in 2016. That same year, Brazil saw approximately 14,000 AIDS-related deaths.
In the U.S., the drug is not as accessible as doctors would like it to be. An anonymous U.S. survey of 2,347 black, white and Hispanic men who have sex with men found that only 3.4 percent had ever taken an anti-HIV pill, Reuters reports.
The CDC says men who sleep with other men remain the most vulnerable group to contracting the HIV virus.
Dr. Margaret Hoffman-Terry, the chair of the board of directors at the American Academy of HIV Medicine, said the study ultimately revealed that men in the U.S. who are eligible for PrEP are not getting it.
"Even in those with insurance and a primary care provider, usage was low," she said.
The researchers noted there were some issues with their study. The data was collected in 2014 and might look somewhat different now. According to Gilead, more than 100,000 U.S. citizens were using PrEP as of July 2017.