While the CDC is advising everyone to get a flu shot, vaccine makers say this is not necessarily true - some people may not need a repeat shot. Whoever is right, even with record production for this coming fall, only half the US population will be able to get vaccinated. Vaccine makers say this season's shot will be a duplicate of last year's. This is because the same flu strains are circulating. If this is the case, young, healthy individuals may still be immune from last season's shot and may not need a booster. It is inevitable that members of the public will become confused and frustrated with conflicting advice. Government health officials say that the protection offered by one season's shot can diminish rapidly -especially for frail, elderly people, as well as those with weakened immune systems. Earlier this month, five vaccine makers said they plan to produce from 166 to 173 million flu vaccine doses for the coming influenza season, surpassing the previous record by 6 million. Americans are taking flu shots in ever growing numbers; over the last ten months over 40% of the population has been vaccinated, compared to 30% in previous years. The CDC (Centers for Disease Control and Prevention) has been aggressively promoting flu shots as a public health priority. It says everyone should be vaccinated, except for children under 6 months of age, individuals with egg allergies, and some other conditions. The emergence of swine flu in 2009 probably triggered another rush for shots. US authorities have become more aggressive in promoting flu shots than their European counterparts. Health authorities tend to use the changing flu strains argument when encouraging people to get vaccinated. As the same strains as last year are expected to be circulating this coming fall, many experts say that not everyone necessarily needs two consecutive years of shots. The CDC says that at the best of times, flu shots are only about 70% effective. Repeat shots should be given to as many people as possible to protect a whole population, they say. Studies do not seem to agree on how quickly a flu shot's protection starts to wane. According to the CDC, one's immunity drops by at least 66% over a year. Other studies suggest that in children protection last for up to three years, and at least one year in adults. The truth is nobody, not even the experts, really know how long protection lasts. If nobody is really sure, surely the best bet is to vaccinate as many people as possible. Source : Flu Vaccines Will Be Enough For Half The Population - So Who Should Get Them?