Mandatory Flu Shots for Toddlers Attending Daycare in New Jersey: WHERE is the Science?
The Public Health Council voted to require New Jersey children attending preschool or licensed day care to get annual flu shots, and to get three additional vaccines for youngsters starting Sept. 1, 2008.
This was justified, not by reference to scientific research, but with this statement:
“The amendments to the rules governing immunizations will have a direct impact on reducing illnesses, hospitalizations and deaths in one of New Jersey’s most vulnerable populations – our children,” said Commissioner Jacobs. “Vaccinations have proven to be one of the most effective and safe forms of disease prevention.”
However, a Cochrane systematic review found that:
In children under two, the efficacy of inactivated vaccine was similar to placebo.
and:
That no safety comparisons could be carried out emphasizes the need for standardisation of methods and presentation of vaccine safety data in future studies. It was surprising to find only one study of inactivated vaccine in children under two years, given recent recommendations to vaccinate healthy children from six months old in the USA and Canada. If immunisation in children is to be recommended as public–health policy, large–scale studies assessing important outcomes and directly comparing vaccine types are urgently required.
How can a vaccine that has no effect on babies and toddlers reduce illness, hospitalisations, and deaths in little ones? Compulsory placebos? This is not evidence-based medicine.
Officials in NJ based this mandate on advice from the CDC which states:
Children less than 2 years old—even healthy children—are at high risk of ending up in the hospital if they get the flu. Vaccinating young children…can help protect them from getting sick.
Still searching for the science, I turn to the CDC material on influenza directed at health professionals and found a brief section on the efficacy of this vaccine for children:
A 4-year randomized, placebo-controlled trial of children aged 1-15 years found vaccine effectiveness ranging from 77% to 91%, following only one dose of vaccine given to previously unvaccinated children (Neuzil, Pediatric Infectious Diseases Journal, 2001).
Another 2-year study of children aged 6-24 months found that the vaccine was 66% effective against laboratory-confirmed influenza in year 1 of the study. Only children who were fully vaccinated (i.e. had either 2 doses if not previously vaccinated, or 1 dose if previously vaccinated) versus unvaccinated children were included in the analysis. In the other year, few cases of influenza occurred, making it difficult to assess the vaccine’s effectiveness.
A study of influenza vaccine effectiveness among >5,000 children aged 6-23 months found vaccine effectiveness of 49% against clinically diagnosed pneumonia or influenza among fully vaccinated children (Ritzwoller, Pediatrics 2005).
All of these studies together suggest substantial benefit from influenza vaccination of children.
So, who should we trust, the CDC or the Cochrane Collaboration? Here are some comments and links on Cochrane:
If we ever had a scientist in charge of health, instead of tinkering with payments to big pharma, they would do one simple thing: move hell and high water to collect and collate the best and cheapest evidence on healthcare. First you would give huge amounts of money to the Cochrane Collaboration, which collects and collates data independently on all healthcare interventions (and is quietly one of the most subversive organisations ever to be created, because it blows the lid off false commercial claims). Doctors waste money by irrational (sic)prescribing decisions, so give them clean, clear, accessible information, and that will stop ¹
The Cochrane Collaboration is a group of over 11,500 volunteers in more than 90 countries who apply a rigorous, systematic process to review the effects of interventions tested in biomedical Randomized controlled trial. A few more recent reviews have also studied the results of non-randomized, observational studies. The results of these systematic reviews are published in the Cochrane Library.
The Cochrance Collaboration was founded in 1993 under the leadership of Iain Chalmers. It was developed in response to Archie Cochrane’s call for up-to-date, systematic reviews of all relevant randomized controlled trials of health care. Cochrane’s suggestion that the methods used to prepare and maintain reviews of controlled trials in pregnancy and childbirth should be applied more widely was taken up by the Research and Development Programme, initiated to support the United Kingdom’s National Health Service. Funds were provided to establish a ‘Cochrane Centre’, to collaborate with others, in the UK and elsewhere, to facilitate systematic reviews of randomized controlled trials across all areas of health care.²
So, the Cochrane Collaboration seems to have a good, solid reputation. As to the trustworthiness of the CDC, we’ve already posted two articles on the topic: Parents! and Measles. We should have a brief look at the studies cited by the CDC to support flu vaccines, though, just to see if they picked out high quality research.
The first article the CDC mentions in support of the effectiveness of flu vaccines in children has some problems. Here is a bit from the abstract:
During the 5 years of the study, 791 children younger than 16 years received 1809 doses of either inactivated or cold-adapted vaccine or placebo. The vaccines were well-tolerated, and there were no serious reactions. Inactivated trivalent influenza vaccines were 91.4 and 77.3% efficacious in preventing symptomatic, culture-positive influenza A H1N1 and H3N2 illness, respectively. The efficacy of the inactivated vaccine based on hemagglutination inhibition assay seroconversion was 67.1 and 65.5%, respectively, for H1N1 and H3N2 serotypes.³
This study looked at data from 1985 to 1990. There were 791 children from 1 year old to 16 years old involved. The children under the age of two are obviously a small sub-set of this group. In addition, the study is a reanalysis of original data which was gathered over 20 years ago now. The CDC is stretching to say that this study provides strong support for vaccinating children under the age of two with the influenza vaccine.
The other study the CDC references:
Design and Methods. Outpatient and emergency department visits and immunization records were used to conduct a retrospective cohort study among children 6 months to 8 years of age.4
What is a “retrospective cohort study”? It means that the scientists went and dug back through the records and then analyzed the data they collected. This type of study is not rated high in the eyes of experts in the field of evidence-based medicine. Too many opportunities for error or bias.
In summary: New Jersey based the mandate for daycare influenza vaccination (including babies and toddlers under 2 years of age) on the CDC recommendation, which leans on some rather weak studies. They are ignoring the excellent analysis by the top-rated Cochrane Collaboration. Poor kids. Useless vaccines, containing some rather yucky ingredients. Poor NJ taxpayers, not to mention everyone who buys medical insurance in NJ. Influenza vaccines for toddlers will inflate health-care expenses and accomplish nothing.
(1) Ben Goldacre at BadScience [note: we've been informed that this site has dangerous spyware hanging around, so approach with caution, sorry!]
(2) Wikipedia on Cochrane
(3) Neuzil
(4) Ritzwoller
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