Every winter, people line up at pharmacies to receive flu shots. However, scientists are basically guessing on the strain of flu that will be prevalent that year and then develop a vaccine to fight that particular strain. During the 2012-2013 flu season, the CDC guessed wrong, although they never said as much. While its chosen vaccine helped prevent the flu in half of children under six months of age, it was almost completely ineffective for people over age 65, a very vulnerable population. And according to Immogeneticist Dr. Hugh Fundenberg, flu shots increase your odds of getting Alzheimer's disease, but there's no proof of that or that it's harmful to get the shot.