Avian Flu Diary: AAP: Systemic Review Finds Childhood Vaccines Very Safe (Again)

# 8798

The American Academy of Pediatrics (AAP) has announced today the early findings of a new systemic review of childhood vaccine safety research that will hopefully be reassuring to parents who still harbor concerns over vaccine safety.

While no medicine – including vaccines – are 100% benign, or are without the risk of rare adverse effects, childhood vaccines have an enviable safety record. Something that this study proves out again.

First the press release from the AAP, then I’ll have a bit more.

Systematic Review of Vaccine Safety May Allay Parents' Concerns
7/1/2014
For Release: July 1, 2014
A systematic review of research on vaccine safety, published online July 1 in Pediatrics, updates a 2011 Institute of Medicine (IOM) report on the safety of vaccines recommended for children aged six years and younger. The study, "Safety of Vaccines Used for Routine Immunization of U.S. Children: ASystematic Review," to be published in the August 2014 Pediatrics, is part of a larger report on the safety of vaccines for adults, adolescents and children requested by the Agency for Healthcare Research and Quality.

Researchers from the RAND Corporation conducted a systematic review of the evidence published since the IOM report on vaccines for children under age 6, including DTaP (diphtheria, tetanus and acellular pertussis), hepatitis A, hepatitis B, influenza, meningococcal, MMR (measles, mumps and rubella), and varicella vaccines. The report also reviews the evidence on several childhood vaccines that were not studied in the 2011 IOM report, including Haemophilus influenza type b (Hib), pneumococcal, rotavirus, and inactivated poliovirus vaccines. The evidence is strong that MMR vaccine is not associated with autism, which is consistent with previous reviews on the topic. Researchers also identified strong evidence that MMR, DTaP, Td (tetanus), Hib and hepatitis B vaccines are not associated with childhood leukemia.

Studies did show an association of several serious adverse events with vaccines, but these events were very rare, such as intussusception after rotavirus vaccine. Researchers conclude the findings may allay concerns of some parents about vaccine safety.

The internet, and Hollywood, are filled with self-proclaimed experts claiming – despite all evidence to the contrary – that childhood vaccines cause autism. And sadly, for some percentage of the population – who already distrust `big pharma’ -that message has stuck.

The real dangers come from the diseases that these vaccines are designed to prevent.

Just last week we saw a report (see California DPH: Whooping Cough Epidemic Continues) on the resurgence of a vaccine preventable disease that was all but wiped out in this country 30 years ago. But Pertussis is back with a vengeance – in part – due to a reluctance of parents to get their kids vaccinated.

Similarly, we saw in late May from a CDC Telebriefing: Worst US Measles Outbreak In 20 Years, that this childhood scourge – declared eliminated 14 years ago in the United States – is raging once more: This from Dr. Anne Schuchat, of the CDC:

“The current increase in measles cases is being driven by unvaccinated people, primarily U.S. residents, who got measles in other countries, brought the virus back to the United States and spread to others in communities where many people are not vaccinated.”

For those who may be convinced that measles is a `harmless’ childhood illness, we get this little factoid from the CDC:

About 30% of measles cases develop one or more complications, including

Pneumonia, which is the complication that is most often the cause of death in young children.

Ear infections occur in about 1 in 10 measles cases and permanent loss of hearing can result.

Diarrhea is reported in about 8% of cases.

These complications are more common among children under 5 years of age and adults over 20 years old.

Even in previously healthy children, measles can be a serious illness requiring hospitalization. As many as 1 out of every 20 children with measles gets pneumonia, and about 1 child in every 1,000 who get measles will develop encephalitis. (This is an inflammation of the brain that can lead to convulsions, and can leave the child deaf or mentally retarded.) For every 1,000 children who get measles, 1 or 2 will die from it. Measles also can make a pregnant woman have a miscarriage, give birth prematurely, or have a low-birth-weight baby.

Frustratingly, this push back against childhood vaccines also extends to the yearly flu shot for adults (including pregnant women), which based on some of the research we’ve seen, may actually help reduce the incidence of autism and other developmental diseases in children.

In 2012 research by a team at UC Davis found that fever (from any cause) during pregnancy more than doubled the odds of having a child with autism or developmental delays (see Is Maternal Influenza or Fever During Pregnancy Associated with Autism or Developmental Delays? Results from the CHARGE (CHildhood Autism Risks from Genetics and Environment) Study Zerbo et al.)
In November of 2012, in Of Pregnancy, Flu & Autism, we saw a study that found a twofold increase in autism among children with prenatal influenza exposure, and a threefold increase in autism among children with prolonged prenatal fever exposure
And just last year (May, 2013) we looked at a JAMA Psychiatry report that linked bipolar disorder (BD) to influenza exposure while still in the womb (see Pregnancy, Influenza, & Bipolar Disorder In Offspring).

These studies are admittedly small and less than conclusive, and while they suggest an increase in relative risk over pregnancies without fever or viral infection – in terms of absolute risk – the odds that a mother’s fever or viral infection during pregnancy would result in a developmentally challenged child remains low.