The early research conducted by Antonelli was focused on elucidating the in vivo and in vitro mechanisms regulating the production and activity of interferons during viral infections. His research group currently investigates the role of innate immunity, as well as the pathogenesis, diagnosis, and control of several viral infections, including HIV, HCV, major respiratory viruses (such as SARS-CoV-2, RSV, and influenza viruses), and HPV.