Sears is a nationally known pediatrician, father of three, and author of The Vaccine Book: Making the Right Decision for Your Child. Sears has graciously offered to extend his expertise about vaccines through a monthly column where YOU ask the questions…and he answers them. See the bottom of this post for details about how you can submit a question.
If you want more information now, you should really just buy his book (read my review here). It’s comprehensive, objective, and the only one of its kind on the market.
QUESTION: If my baby/toddler has the first shot of a vaccine series (HIB, DTaP, or Rotavirus, for example) and doesn't experience any "reactions"/side effects, is it safe to say that he won't experience them when he gets the second (or third or fourth...) shot?
ANSWER FROM DR. SEARS: While handling the first round of shots is somewhat of an indication that the next rounds will be well tolerated, this is by no means a guarantee. Some babies will show ever-increasing reactivity with each subsequent round. And the toddler round of boosters (the 4th dose in the entire series) is more known for being fairly reactive, even if the first three were fine.
You just never know. A baby could react at any time without any prior indication. Fortunately, MOST babies handle these rounds of shots without much reaction.
If a baby DOES have a tough reaction to any round of shots, I feel it would be safer to spread those shots out more with subsequent rounds. Maybe only get one at a time so you can see which vaccine may be the more reactive one. By spreading the shots out, you would be less likely to have a tough reaction again.
If you have a question about vaccines for Dr. Sears, send an e-mail with “Ask Dr. Sears” in the subject line to email@example.com.