Tony Fauci took over as the head of the National Institute of Allergy and Infectious Diseases (NIAID, often pronounced Ni-add.) in 1984 at the height of the AIDS epidemic. Since then, he’s served at National of Institutes of Health agency under Reagan, Bush 1, Clinton, Bush 2 and now Obama. He’s also been through the resurgence of TB, SARS, H1N1 and the rise of the Methicillin-resistant Staphylococcus aureus (MRSA) and other drug-resistant infections.

Tonight he returns to his undergraduate alma mater, Holy Cross in Worcester, where he’ll give a talk on “Emerging and Re-emerging Infectious Diseases: The Perpetual Challenge to Global Health,” The event is free and open to the public. And, for those who can’t make it or get in, it will be streamed live.

The Globe offers a short Q & A with Fauci in this morning’s paper.

When I first started taking care of patients with HIV . . . by the time they came to me, their life expectancy was a mean of 26 weeks. Today with combinations of the extraordinary drugs that we have available for people with HIV infection . . . if they come in infected at say, 20 years old, and we put them on therapy, you can mathematically model that they will live another 50 years to the time they are 70. And because of that, people somehow unfortunately and inaccurately do not perceive HIV/AIDS in this country, at least, as being as serious as it really

He also offers some hope about one of the toughest battles in the HIV wars – the search for a vaccine.