The Endless Hunt For The Perfect Flu Vaccine
In 1919 Edward Rosenow from the Mayo Clinic in Rochester, Minnesota, isolated several bacteria from the sputum and lungs of flu patients in Rochester, formulated a vaccine that contained five different kinds of bacteria, and doled it out to 100,000 people. For the first several years the influenza vaccine contained only one strain, the influenza A virus, because, as far as anyone knew, that was the only kind of influenza out there. For the 2016-7 flu season, most of the vaccine doses manufactured in the US targeted four different strains. One study compared 18 different groups over 10 influenza seasons and found that the vaccine reduced the overall winter mortality rate in older people by an astonishing 50%.
Source: www.theguardian.com