He is known for his work on HIV/AIDS and was the first African American to hold a full tenured professorship in basic research at Johns Hopkins School of Medicine.

Later that year, as a Rhodes Scholar, he started attending Oxford University, where he studied the biology of cytotoxic T-cells with Professor Andrew McMichael and became an expert in monoclonal antibody technology and cell adhesion molecules.

The protein discovered by Hildreth as a graduate student was the basis for an FDA-approved drug, Raptiva, that was used to treat psoriasis.

He currently serves on the FDA's Vaccines and Related Biological Products Advisory Committee and as a member of the COVID-19 Health Equity Task Force appointed by President Joe Biden.

[4] He has made appearances in national broadcast and print media (MSNBC, CNN, Wall Street Journal, New York Times, NBC, Yahoo Finance, PBS,[5] Modern Healthcare,[6] and others) as an expert on COVID-19 science and disparities.

For example, the demonstration that HIV-1 adopts host proteins to exploit their function to its advantage, the observation that lipid rafts are involved in HIV-1 assembly and entry, proposed HIV-1 as a Trojan exosome, and natural pseudotyping enables HIV-1 to directly infect epithelial barrier cells in the female genital tract.

In 1986, he began working on research to create a vaginal microbicide cream that blocks HIV infections, testing it in Zambia and South Africa in the 2000s.

[1][2] Hildreth has also worked in the Southern United States, where the majority of new HIV infected people are African Americans.