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
Jonas Salk making money." That belongs "in the category of mink coats and Cadillacs—unnecessary", he said. In the years after Salk's discovery, many supporters, in particular the National Foundation, "helped him build his dream of a research complex for the investigation of biological phenomena 'from cell to society'." Called the Salk Institute for Biological Studies, it opened in 1963 in the San Diego neighborhood of La Jolla. Salk believed that the institution would help new and upcoming scientists along in their careers, as he said himself, "I thought how nice it would be if a place like this existed and I was