THIMEROSAL IN VACCINES

Mercury's Removal Doesn't Stop Autism's Rise, Study Shows
Cases of the disorder continued to increase in California children from 2004 to 2007, even after a preservative was removed from vaccines. By Jia-Rui Chong, Los Angeles Times Staff Writer (01-08-08) link
Findings from a CDC publishes followup study of thimerosal exposure and neurodevelopmental delay have been published in a NEJM article by Thompson et al. [free link to full text] (09-27-07)

CDC has also posted a transcript of a Sep 26 2007 press briefing including Q&A following the briefing [link].

More than 1000 children with different thimerosal exposures from the prenatal period until 7 months of age were evaluated by a battery of 42 neurodevelopmental tests at 7-10 years of age. The analyses involved 378 comparisons of outcomes including possible differences of effects on boys vs. girls. Ninety-five percent of the analyses showed no differences in outcomes by thimerosal exposure. Five percent of the comparisons revealed differences in outcomes by thimerosal exposure. Using a cutoff of 5% for statistical significance, these findings would be expected by chance. More findings of slight improvement in scores with increasing thimerosal exposure were found than findings of decreased performance with increasing exposure. The effects in both directions on test performance were quite small. These findings have been interpreted as probably chance occurrences by the authors.

The study did find an increased rate of tic disorders associated with thimerosal. This finding had been observed in two prior studies and will be investigated further.

This study will undoubtedly undergo intense evaluation by many groups. CDC will be making the dataset available publicly so that other groups can conduct additional analyses.
A Canadian study reconfirms older findings ruling out an association between pervasive developmental disorder [PDD] (including autism) and high levels of ethylmercury exposures or MMR vaccines.
The specific findings by Fombonne et al in Pediatrics include:
• Autism and Thimerosal - thimerosal exposure was unrelated to the increasing trend in PDD prevalence.
• Autism and MMR - no association between MMR vaccinations (both 1 and 2 doses) and autism or PDD rates.

The study found the highest rates of PDD in children with no thimerosal exposure (from vaccines). The study also noted a slight decrease in the rates of MMR vaccine at the same time as rates of PDD were increasing.

Fombonne E et al. "Pervasive Developmental Disorders in Montreal, Quebec, Canada: Prevalence and Links With Immunizations." Pediatrics 2006;118(1);139-50. [pubmed abstract] (07-2006)
Table showing Thimerosal Content in Some US Licensed Vaccines link - updated October 2006.
Burbacher et al. Comparison of Blood and Brain Mercury Levels in Infant Monkeys Exposed to Methylmercury or Vaccines Containing Thimerosal. Environmental Health Perspectives 2005;113. [abstract] [full article (pdf - 1047K)]. (04-21-05)
A new Influenza vaccine will be available for the 2005/6 Flu Season
The FDA has approved the license supplement of sanofi pasteur (formerly Aventis Pasteur) to market a formula of their influenza vaccine produced without introducing preservatives at any step in the manufacturing process. Fluzone®, Influenza Virus Vaccine, No Preservative, Pediatric Dose is the only influenza vaccine approved for use in the U.S. in children as young as 6 months. The vaccine will be available in 0.25 mL pediatric dose and 0.50 mL for children 3 years and older. complete press release (03-09-05)
MMR Vaccination and Pervasive Developmental Disorders: no association. Smeeth, et al report that MMR vaccination is not associated with an increased risk of pervasive developmental disorders (PDDs). The authors studied 1294 affected children and 4469 controls in the General Practioners Database in the United Kingdom and "We have found no convincing evidence that MMR vaccination increases the risk of autism or other PPDs". Lancet 2004;364(9438):963-9. (09-15-04)
Institute of Medicine reports that MMR and thimerosal do not cause autism. The IOM committee concluded that the body of epidemiological evidence favors rejection of a causal relationship between the MMR vaccine and autism and between thimerosal-containing vaccines and autism. May 17, 2004
New Law Limits Actions Over Vaccine Preservative - an article in Harvard's Focus looks at vaccines and thimerosal, including commentary by IVS's Dr. Halsey on autism as well as the Homeland Security Bill. (01-10-03)
Vaccines Do Not Cause Autism - Dr. Halsey clarifies his position after recent media attention: NYT Magazine, NPR radio programs Morning Edition and Diane Rehm Show (11-11/13-02)
Report issued by the IOM's Immunization Safety Review Committee, Immunization Safety Review: Thimerosal-Containing Vaccines and Neurodevelopmental Disorders (10-01-01)
Balancing Risks and Benefits: Primum non nocere Is Too Simplistic is Neal Halsey and Lynn Goldman's response to an earlier commentary regarding the delay of the birth dose of hepatitis B vaccine. They also include new information regarding methyl- and ethyl-mercury. (08-02-01)
Information from the IOM meeting on Thimerosal-Containing Vaccines and Neurodevelopmental Outcomes, including a slide show presentation by IVS director, Dr. Halsey entitled "Commentary of Potential Risk from Thimerosal for Infants". (07-16-01)
Thimerosal Questions and Answers Link to CDC National Immunization Program web site.
Information from the June 21, 2000 ACIP meeting regarding thimerosal: new vaccines without thimerosal, studies of mercury exposure in children and study of blood mercury level.
New PHS/AAP statement and data on thimerosal in vaccines: June 22,2000.
New Preservative-Free Hepatitis B Vaccine approved by FDA for pediatric and adolescent use (03-31-00).
Limiting Infant Exposure to Thimerosal in Vaccines and Other Sources of Mercury Neal Halsey's editorial on ways to cut down on infant exposure to mercury. (JAMA 1999;282(18):1763-5). (11-10-99)
CDC Announcement regarding a Thimerosal-free Hepatitis B Vaccine On September 10, 1999, the CDC announced the availability of a thimerosal-free hepatitis B vaccine and recommended that routine hepatitis B vaccination policies for all infants be reintroduced immediately in hospitals where these policies had been discontinued.
Thimerosal in Vaccines — an Interim Report to Clinicians The American Academy of Pediatrics has also recommended restoring routine neonatal immunization for infants born to HBsAg negative women when vaccines free of thimerosal preservative became available (Pediatrics September 1999;104:570-4).
New Thimerosal-free Hepatitis B Vaccine for Use in Infants On August 27,1999, the FDA approved a modified hepatitis B vaccine (Recombivax HB) produced by Merck. The new product is distinguished from the original by an orange streak on the label stating "Preservative Free". Use of the new product should be limited to infants at this time in order to assure sufficient supplies for all children.
IVS Perspective on the Use of Thimerosal-Containing Vaccines Slide Show presentation from August 11/12, 1999 Workshop on Thimerosal and Vaccines
Joint Statement of the American Academy of Pediatrics (AAP) and the U.S. Public Health Service (PHS) (7-7-99)
Thimerosal, a Mercury-containing Preservative Used in Some Vaccines Statement of the IVS position on mercury-containing vaccines. (7-8-99)

This page was last updated on July 18, 2008