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 ... who read everything he could lay his hands on," according to one of his fellow students. Students had to cram a four-year curriculum into just three years. As a result, most dropped out or flunked out, despite the school's motto "study, study, study." Of the students who graduated, however, most would have the grades to enroll in CCNY, noted for being a highly competitive college. Salk enrolled in CCNY from which he earned a Bachelor of Science degree in chemistry in 1934. Oshinsky writes that "for working-class immigrant families, City College represented the apex of public higher education. Getting