Over the course of the years, I have accumulated a number of vaccinations - polio, tetanus, mumps/measles/rubella, yellow fever, meningitis, hepatitis, the usual suspects. Many people get vaccinations against flu every year to keep up to date with recent mutations of the virus. So I wonder if there is a limit to the number of immunities the human body can develop. When you get more and more vaccinations is there a point when where further action against other diseases will not lead to the production of antibodies because your immune system is preoccupied with producing other antibodies from previous injections? Can new vaccinations affect the effectiveness of previous ones by “replacing” them?