A 49-year-old member asked:
if a live vaccine gives life long immunity, why do we get booster vaccines?
1 doctor answer

Dr. James Ferguson answered
46 years experience Pediatrics
Varies: For some viruses (smallpox) a vaccine likely produces lifelong immunity.Others (varicella) produce immunity in only 85% with one dose,increasing to >95% with 2., and we don't know if the immunity will be life long. MMR often takes at least 2 doses and may take more. Vaccine technology has improved over the years, but we cannot replicate what nature does naturally. Lifelong is not true in all cases
Answered on Nov 10, 2014
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more. Get help now:
90,000 U.S. doctors in 147 specialties are here to answer your questions or offer you advice, prescriptions, and more. Get help now:
People also searched for:
Connect by text or video with a U.S. board-certified doctor now — wait time is less than 1 minute!
24/7 visits
$15 per month