Salk accepted a position at the University of Pittsburgh School of Medicine, where he established his Virus Research Laboratory. This laboratory would become the epicenter of his polio research.

Salk and his team worked tirelessly to develop an inactivated (killed) poliovirus vaccine. This involved cultivating different strains of the poliovirus, inactivating them with formaldehyde, and then testing their immunogenicity. His approach was revolutionary, as it challenged the prevailing wisdom that only a live, attenuated virus could provide effective immunity.

Salk conducted initial trials of his polio vaccine on himself, his family, and volunteers. The results were promising, demonstrating that the vaccine was safe and effective in producing antibodies against poliovirus.

The National Foundation for Infantile Paralysis sponsored a massive nationwide field trial of the Salk vaccine, involving over 1.8 million children. This was one of the largest public health experiments in history, and its success would have profound implications for global health.

The results of the 1954 field trials were announced, revealing that the Salk vaccine was safe and effective in preventing polio. This announcement was met with widespread celebration and relief, marking a turning point in the fight against this crippling disease.

Following the announcement of the vaccine's success, massive vaccination campaigns were launched across the United States and around the world. The incidence of polio plummeted dramatically, saving countless lives and preventing untold suffering.

Shortly after the vaccine's release, a batch produced by Cutter Laboratories was improperly inactivated, leading to cases of polio in vaccinated individuals. This incident, known as the Cutter Incident, caused public anxiety and temporarily slowed down the vaccination program. The incident prompted stricter quality control measures in vaccine production.