Doctor answers your questions about vaccines

Why do babies get combination shots? Why do they get their first shot so young? Why don't we just slow down the vaccination schedule?

Parents asked a doctor who specializes in vaccines to answer some of their questions as part of a package of stories about parents' fears surrounding vaccines and autism. Dr. Gregory Poland, director of the Mayo Clinic Vaccine Research Group, answered. Poland helps set national vaccine policy as a liaison member of the federal Advisory Committee on Immunization Practices.

Several parents asked: Why can't children get combination shots separated, or get shots on a slower schedule?

There is no evidence of either safety or efficacy by separating all the vaccine doses. … There is evidence of both safety and efficacy if vaccines are used in the manner they were studied. … There is no credible evidence supporting fears of "overloading" a child's immune system by vaccines, or in somehow causing developmental disorders. … Recent outbreaks of diseases like measles have led to severe illness and even death among unimmunized infants and children. The longer the schedule is spread out, the greater the risk of exposure while susceptible.

Do children need the hepatitis B vaccine at such an early age? My daughter was offered the vaccine for her newborn.

Up to 50 percent of women who are hepatitis B carriers remain unidentified at the time they give birth — thereby transmitting it to their infants. The younger you are when infected, the higher the risk of becoming a chronic carrier.

Why can't babies get one vaccine instead of three or four every time they go to a doctor?

Combining immunizations is easier and safer (fewer injections) for the baby, while ensuring high rates of coverage. Increasing the number of visits increases costs and means babies would miss more shots.

Why is it unsafe to vaccinate a baby before 2 months but at 2 months and one day it is determined safe?

It is not a question of safety, but rather a measure of immune system function and the likelihood of developing a protective response for a given vaccine type.

It is my understanding that in order to maintain immunity from a vaccination, you must repeat it every five to seven years. Is there a vaccine schedule through adulthood?

There is. … The interval for repeat doses is different for each vaccine. (To see the adult vaccine schedule, go to www.cdc.gov/vaccines.)

I am 83 years old. I have had three attacks of shingles in the last five years. Should I get the measles vaccine?

There is unlikely to be a need for you to have the measles vaccine. You should consider talking with your physician about the shingles (zoster) vaccine.