A study published in Pediatrics today confirms a slightly elevated risk in febrile seizures in children who receive the combo MMRV (Measles-Mumps-Rubella-Varicella) shot between 1 and 2 years of age. If it were my child, I would NOT get the combo MMRV shot, even if the elevated risk of seizure is extremely low. The American Academy of Pediatrics will likely recommend the same. None of us ever want our child to be put at increased risk. Or to be part of a statistic.

This study found children receiving the combo MMRV had double the risk of febrile seizure compared with those children who got the MMR and Varicella (Chicken Pox) shots individually. Data shows 1 in 2300 children could have a febrile seizure after the combo shot. So, like journalist Madonna Behen reported today, I do not recommend the combo.

From the way I see it, both as a mom and as a pediatrician, if the risk is increased, it is meaningful. And, because children who get the 2 shots separately are equally protected against Measles, Mumps, Rubella, and Chicken Pox (Varicella) I recommend the safer route of 2 shots.

Why the hype today? When new information is published about shots, many parents become hesitant. News on immunization is often confusing and seemingly scary. I am not hesitant about shots, but I will always recommend the full immunization conferring the lowest-risk. For my patients and for my own kids. (It is unlikely that you need to ask your pediatrician about the combo MMRV, as supply is low and likely not even in your pediatrician’s office.) This new data on the MMRV shot is apart from other recommended combination shots given during infancy and childhood. (See recommended shot schedule here.)

With no increased benefit from the combination shot vs. the 2 shot dosage, I can’t recommend the combination MMRV simply to avoid one less poke at the office visit. That’s how I have counseled families over the last two years; In February 2008, studies with similar results propelled the ACIP to step away from recommending the combination MMRV over the individual shots. My boys got both their MMR and Varicella shots after they turned 1 year of age. But because of this data, I didn’t ask for the MMRV shot…

Some history/perspective:

  • Febrile seizures are relatively common in young children between 6 months to 5 years. They are usually self-limited (seizure stops without any intervention) and cause no long-term problems or epilepsy. Febrile seizures are short seizures that occur in up to 4-5% of all young children. Although they do not cause long-standing damage or disability, they can be very frightening to parents.
  • Measles, Mumps, Rubella, and Varicella infections cause far worse outcomes. Did you know that before the introduction of the chicken pox vaccine in 1995, more than 100 people died in the US every year? And since measles vaccine started in the 1960’s, there has been a 99% decline in the number of cases in the US?
  • Immunizations work to prevent illness in nearly all children (95%) who get them. But, nothing is perfect: 5% of children who get a particular shot are not protected. We have to rely on immunized members of the community to protect us all, particularly young infants (too young to be vaccinated) and sick children (can’t receive the shots).

Children need 2 doses of MMR and 2 doses of Varicella to protect them against the illnesses. Starting at age 12-15 months, we recommend the first dose of MMR and the first dose of Varicella. Children then need a second dose, or “booster” of each shot, prior to kindergarten or sometime between age 4 and 6 years.

Resources if you feel like reading more:

I spoke with Madonna Behen last week and she reported my thoughts while outlining the findings of the study for Health Day.

You can also read a summary here by Liz Szabo.

Concerns about vaccine safety.