The controller is priced at $50 USD, and will release alongside Valve's Steam Link service, which is also slated for a $50 release. The controller's worldwide pricing will be announced closer to November, Valve said. Hands-on With the Updated Valve Controller. 01:37.
Polio rose to epidemic proportions in the United States with more than 21,000 cases reported in 1952 [3]. With the development of effective vaccines against the virus during the 1950s the incidence of poliomyelitis went in decline and the last case of wild-type virus reported in the United States was in 1979.
Salk's Impact. There were 28,985 cases of polio in 1955, and there were only 14,647 cases in 1956. The Salk vaccine, also called the inactivated polio vaccine (IPV), is credited with the enormous decrease in cases. The vaccine contained three strains of the polio virus, and it provided at least partial immunity.