It would be necessary to focus on the different variants of flu each year, if we rely on one vaccine per year. This TED-Ed-produced video discusses the steps scientists take to make the flu vaccine each year and the rationale behind why we ought to continue getting vaccines. Every year , flu sufferers at hospitals across all over the world are tested for the type of virus that caused their condition. Scientists gather information from the patients to discover the strains that are most hazardous for the upcoming flu season. They then create vaccines that target these viruses. There are more than 100 different subtypes of the flu is among the most difficult viruses to affects human beings. There is a World Health Organization gathers scientists every year for two days to create an anti-flu vaccine. These shots help minimize the severity of the symptoms , and also protect the population by keeping them from spreading and being carriers of the virus. ci8un1bhcr.