A vaccine for HIV, the virus that causes AIDS, is beginning human trials, says Moderna, its developers. Samantha Riedel:
We are tremendously excited to be advancing this new direction in HIV vaccine design with Moderna's mRNA platform," said IAVI president and CEO Mark Feinberg in the announcement. "The search for an HIV vaccine has been long and challenging, and having new tools in terms of immunogens and platforms could be the key to making rapid progress toward an urgently needed, effective HIV vaccine."
More on mRNA vaccines at Wikipedia and the CDC. This is the type that has proven most successful at preventing Covid infection and moderating its symptoms.