Harry Weaver (neuroscience) died at his home in San Clemente, California, age 68. The polio vaccine was discovered and developed by Jonas Salk between 1952 and 1955. Weaver, acting as the Director of Research at the National Foundation for Infantile Paralysis, now known as the March of Dimes,from 1946 to 1953, supported Salk's work with a sense of urgency for the development of the Polio vaccine. Weaver's urgency for developing a vaccine as quickly as possible was somewhat counter to the development of the Oral polio vaccine by Albert Sabin between 1954 and 1961. However, his support of Salk's vaccine was considered to
Polio vaccine attenuate the Sabin 2 strain, and 10 substitutions are involved in attenuating the Sabin 3 strain. The primary attenuating factor common to all three Sabin vaccines is a mutation located in the virus's internal ribosome entry site, which alters stem-loop structures, and reduces the ability of poliovirus to translate its RNA template within the host cell. The attenuated poliovirus in the Sabin vaccine replicates very efficiently in the gut, the primary site of infection and replication, but is unable to replicate efficiently within nervous system tissue. In 1961, type 1 and 2 monovalent oral poliovirus vaccine (MOPV) was licensed, and