[2][1] Crotty went on to a postdoctoral fellowship from 2001 to 2003 with Rafi Ahmed at Emory University Vaccine Center studying immunity to viruses.
[1] He joined the La Jolla Institute for Immunology (LJI) in 2003, as well as the department of medicine of University of California, San Diego, in 2004 as an adjunct assistant professor.
[8] In May 2020, his lab co-published the first detailed analysis of how the immune system responds to SARS-CoV-2, with LJI Professor Alessandro Sette.
[9][10] This research suggested that the human body may be capable of long-term immunity to SARS-CoV-2 following infection or vaccine administration.
[11] Crotty has since published research showing that "uncoordinated" immune cell responses are related to COVID-19 case severity.