All credible scientific research shows the influenza vaccine works exactly as it is supposed to work. The people that think it does not work are those who are very uninformed or scientifically ignorant; those that do not understand that the flu shot is designed to combat what is predicted to be the most dangerous or prevalent strain of influenza that year, and cannot prevent EVERY strain of an extremely varied virus, and those who think that somehow (magically) the flu shot gives you the flu.
Numerous scientific studies prove the flu shot works. It spares people the lingering misery of the flu, and also prevents many cases of pneumonia, and some cases of deadly meningitis. Of course it does not work for everyone. Some people’s system reacts poorly to the shot, and does not form
immunity. This is especially common in the elderly. Other people get the shot too late, when the dread virus is already at work in their bodies. On the whole though, the shot works, to spare each person the flu, and also to create herd immunity, which prevents deadly epidemics.
No, I do not think that the flu shot is effective at preventing the flu because viruses mutate so often that it is unlikely to be the same strain that was given in the inoculation. The flu shot puts a person at risk for Guillain Barr Syndrome, which causes serious disability. The chances that the flu shot prevents against the flu is a gamble that is not worth taking.