Polio vaccine in several other African nations without necessary information, which epidemiologists believe is due to refusals by certain local populations to allow their children to receive the polio vaccine. The Salk vaccine, IPV, is based on three wild, virulent reference strains, Mahoney (type 1 poliovirus), MEF-1 (type 2 poliovirus), and Saukett (type 3 poliovirus), grown in a type of monkey kidney tissue culture (Vero cell line), which are then inactivated with formalin. The injected Salk vaccine confers IgG-mediated immunity in the bloodstream, which prevents polio infection from progressing to viremia and protects the motor neurons, thus eliminating the risk of bulbar
Salk Institute for Biological Studies memorial to Jonas Salk, a golden engraving lies on the floor at the entrance to the institute: "Hope lies in dreams, in imagination and in the courage of those who dare to make dreams into reality." Francis Crick held the post of J.W. Kieckhefer Distinguished Research Professor at the Salk Institute. His later research centered on theoretical neurobiology and attempts to advance the scientific study of human consciousness. He remained in this post at the Salk Institute until his death in 2004. From 22–27 April 2010, the Salk Institute hosted glass sculptures by artist Dale Chihuly to celebrate 50 years