Public health experts have taken a fresh look at the safety records of childhood vaccines and once again pronounced them safe.
A systematic review published Tuesday by the journal Pediatrics notes some evidence of "adverse effects" from 11 vaccines. But the authors of the 13-page report emphasize that such problems are "extremely rare" and that the benefits of routine childhood immunizations far outweigh the risks.
"Vaccines are considered one of the greatest public health achievements of the 20th century for their role in eradicating smallpox and controlling polio, measles, rubella and other infectious diseases in the United States," wrote the study authors, a group of experts from Rand Corp. in Santa Monica, UCLA and Boston Children's Hospital.
However, some parents falsely believe that these vaccines cause autism and other health problems, and they are opting out in increasing numbers. "Parental refusal of vaccines has contributed to outbreaks of vaccine-preventable diseases such as measles and pertussis," the study authors wrote.
At the request of the U.S. Department of Health and Human Services' Agency for Healthcare Research and Quality, the researchers scoured the medical literature for the most scientifically rigorous studies on vaccine safety in kids. In addition to the studies examined in a comprehensive 2011 report from the Institute of Medicine, they identified 67 more studies involving controlled trials. Studies using versions of vaccines that aren't available in the U.S. were not included in the analysis.
Here's what the researchers found about each vaccine:
DTaP: The vaccine against diptheria toxoid, tetanus toxoid and acellular pertussis does not cause type 1 diabetes, according to the available evidence. Likewise, there's no evidence to suggest the DTaP vaccine causes any other medical conditions.
Hib: The Haemophilus influenzae type b vaccine can cause redness and swelling but not high fevers, diarrhea, fungal infections, gastroesophageal reflux disease, convulsions or other conditions serious enough to require hospitalization.
Hepatitis A: One of the studies reviewed demonstrated a "moderate association" between this vaccine and purpura, a short-term condition in which leaky blood vessels cause purple spots to appear on the skin. The link was found only in children between the ages of 7 and 17.
Hepatitis B: A 2010 study reported a heightened risk of autism for boys who got this vaccine in their first month of life, but it had methodological flaws that left the authors of the new report unconvinced. They also said that the evidence suggests there is no link between this vaccine and new or relapsing cases of multiple sclerosis. However, children who are sensitive to yeast did have an increased risk of anaphylaxis. (continued...)
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Posted: 2014-07-04 @ 6:54pm PT
The report's conclusions are hardly convincing. But what's more troubling, is the immense conflict of interest from which the report itself was written. The authors include Margaret A. Maglione, Lopamudra Das, Laura Raaen, Alexandria Smith, Ramya Chari, Sydne Newberry, Roberta Shanman, Tanja Perry, and Courtney Gidengil, all of the corporate-funded think tank, RAND Corporation.
While the report itself was funded by the US government, the RAND Corporation from which its authors were drawn is funded by the very corporations that manufacture various vaccines, including the MMR vaccine which was the primary focus of the report. Big-pharma sponsors of RAND include GlaxoSmithKline (GSK) and Merck - that latter of which is listed by the US Center for Disease Control (CDC) specifically as the manufacturer of the MMR vaccine.
It is admitted in the "conclusions" that there are severe limitations in this so called study which simply looks at old studies - all studies on any vaccine in the current schedule are done by comparing one vaccine with another vaccine - so none of the studies looked at were on vaccinated vs unvaccinated people or an inert placebo as this is considered unethical. However a retrospective study could easily be done as there are a large body of unvaccinated to choose from. Also this study admits that MMR and other vaccines have not been studied for their ability to cause auto immune disease, one of the most rampant illnesses in our society; that severity of Adverse Reactions are inconsistently reported due to there being no compulsory reporting to VAERS and only 1 - 10% of adverse events are reported. The majority of studies did not investigate or identify risk factors for Adverse Events and this is a huge hole in the safety studies. The study admits that some vaccines are associated with serious adverse events but does not say which ones. Considering that most adverse events are dismissed or not reported, it does not really give parents a sense of confidence.
"RESULTS: Of 20,478 titles identified, 67 were included. Strength of evidence was high for measles/mumps/rubella (MMR) vaccine and febrile seizures; the varicella vaccine was associated with complications in immunodeficient individuals. There is strong evidence that MMR vaccine is not associated with autism. There is moderate evidence that rotavirus vaccines are associated with intussusception. Limitations of the study include that the majority of studies did not investigate or identify risk factors for AEs; and the severity of AEs was inconsistently reported.
CONCLUSIONS: We found evidence that some vaccines are associated with serious AEs; however, these events are extremely rare and must be weighed against the protective benefits that vaccines provide.