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 bi-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: My child is sick (has a cold/a stuffy nose/the flu) and is scheduled to have his/her shots today. Should we proceed with the vaccinations or wait until he/she is healthier?
ANSWER FROM DR. SEARS: It’s inevitable. The day before your baby’s check up her nose starts to run. Or she’s just coming off antibiotics from an ear infection a few days before her next check up and shots. What do you do? Some people worry that vaccines may temporarily lower a child’s immune system, thus making any present illness potentially worse. Although this hasn’t been proven in research studies, it theoretically makes sense. As the immune system is working on the vaccines, other parts of the immune system may be “distracted” or may not work at full capacity. So vaccinating may make a mild illness worse. Another complicating factor is that if the shots make your baby fussy and feverish for a couple days, you won’t be able to tell whether it’s her illness that’s worsening or it’s just a reaction to the vaccines. Finally, it may be possible that vaccine reactions may be more likely if a child is already fighting an illness. This issue hasn't actually been researched, but it is a theoretical worry.
If you delay your baby’s shots and come back a few weeks later to get the shots when she’s totally well, there goes another co-pay, another morning off work, and another drive to the doctor's office! The reality is some kids are sick more often than they are well. If we waited for every child to be completely illness-free, some kids would never get vaccinated. In general, if an illness is minor enough to allow a child into school or daycare and doesn’t require antibiotics, then it’s probably OK to give the shots. If a child is sick enough to need antibiotics or to stay home from school or daycare, or is fussy and not sleeping or eating well, then shots should be put off until another day.
Extra cautious patients who don't mind returning another day when baby is at peak health should feel perfectly justified to do so. Even better, cancel your current checkup and simply delay it until your baby is well again.
If you have a question about vaccines for Dr. Sears, send an e-mail with "Ask Dr. Sears" in the subject line to firstname.lastname@example.org.