I got the flu shot this year. Wife did not, she got the flu and was sick for a week. In bed for 2 days straight. Does that tell you anything? I got pneumonia twice and bronchitis in the 1990's. Haven't had pneumonia since, never got the flu. Had bronchitis twice since. Bronchitis was funny, never got a fever, very little if any cold. Just started as a cough and kept coughing for several weeks. Had to take steroids to get over it.
Flu shots do work. Not an experiment. I do take pneumonia shots every 5 years.
