1 OldLinkCj: My PSO2 re-patches whenever I try to put the english patch inâ¦ Anyone had/know how to remove this... 2  Ichijin: Just logged in and checked the title counter. 3  Okay so how do these boosts work.
The measles vaccine was first introduced in the United States in 1963. Before 1989, federal guidelines recommended only one dose of the measles vaccine, so people vaccinated before the guidelines changed generally do not have the coverage thatâs now advised.
History and Development of Flu Vaccines. In 1933, researchers discovered that viruses (influenza virus types A, B, and rarely C) cause influenza (flu). Prior to 1933, a bacterium named Haemophilus was thought to cause the flu. In 1938, Jonas Salk and Thomas Francis developed the first vaccine against flu viruses. This first flu vaccine was used to protect the U.S. military forces against the flu during World War II. Dr. Salk used his experience with influenza vaccine to develop an effective polio vaccine in 1952.