Childhood Vaccines Assessed

Routine childhood vaccines appeared safe with few rare possible side effects

(RxWiki News) Many parents have had questions about childhood vaccines. Yet the research regularly shows them to be safe and effective.

In fact, a recent study reviewed the evidence and found them to overwhelmingly offer more benefit than risks.

The researchers found only a few serious side effects associated with vaccines that were extremely rare.

These rare effects included seizures resulting from high fevers and a bowel condition associated with the rotavirus vaccine.

"Discuss vaccinations with your child's pediatrician."

The study, led by Margaret Maglione, MPP, of the RAND Corporation in Santa Monica, California, reviewed the most recent research available on the safety of vaccines.

The study focused on the routinely recommended immunizations for children.

These include the following vaccines:

  • DTaP (diphtheria, tetanus, pertussis)
  • Hib (for Haemophilus influenzae type B, a type of meningitis)
  • Hepatitis A
  • Hepatitis B
  • Inactivated polio virus
  • Influenza
  • MMR (measles - mumps - rubella)
  • Meningococcal (for forms of meningitis)
  • PCV13 (for pneumococcal disease)
  • Rotavirus (both vaccine types)
  • Varicella (chickenpox)

The researchers pulled 20,478 studies to determine what to include their review. Overall, 67 studies met their criteria.

The evidence showing that the MMR vaccine did not cause autism was very strong.

The researchers also found that the MMR vaccine carried a risk of seizures caused by a fever, known as febrile seizures. These seizures did not cause long-term damage, brain damage or epilepsy.

The evidence also showed that individuals with compromised immune systems were more likely to experience complications from the varicella (chickenpox) vaccine.

Some of the evidence pointed to a risk of intussusception with the rotavirus vaccine, a known possible side effect from past research.

Intussusception is a bowel condition in which one part of the bowel slides into, or "telescopes," another part. It is a serious condition that can require surgery but is very rare, even among recipients of the rotavirus vaccine.

Despite the few adverse effects found from some vaccines, the authors emphasized, "these events are extremely rare and must be weighed against the protective benefits that vaccines provide."

According to Thomas Seman, MD, a pediatrician at North Shore Pediatrics in Danvers, Mass., this study adds strength to the recommendations for immunizations.

"It is clear by these numbers that although there is a very rare incidence of serious side effects, these are significantly less than the risk of acquiring the wild type disease," Dr. Seman said. "This is a well done study with some strong statistics to back up its statements."

He said the study's purpose was clearly to evaluate side effects to determine whether they should be limited to certain children or recommended for all children who do not have contraindications (conditions that mean they should not receive the vaccine).

"Clearly the answer is that all children should receive them," Dr. Seman said. He said another reason to get vaccines on the recommended CDC schedule is that receiving one vaccine can sometimes improve the immune response to other vaccines.

"This is clearly seen when giving the TdaP (tetanus, diphtheria and pertussis) vaccine with the meningitis vaccine," he said. "So, I would not recommend spacing out the doses of vaccines over a longer period of time."

This study was published July 1 in the journal Pediatrics. The research was funded by the US Department of Health and Human Services. The authors reported no conflicts of interest.

Review Date: 
June 30, 2014