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American Family Physician Jun 2017Vaccines are one of the most successful medical advances in modern times. Most vaccine-preventable illnesses are unfamiliar to modern parents. Because of this, parents... (Review)
Review
Vaccines are one of the most successful medical advances in modern times. Most vaccine-preventable illnesses are unfamiliar to modern parents. Because of this, parents are increasingly questioning the necessity of immunizing their children, especially because no vaccine is completely free of adverse effects or the risk of complications. Family physicians should be aware of the risks and benefits of recommended immunizations. Thimerosal is currently used only in multidose vials of influenza vaccine, and exposure through vaccines is not associated with adverse neurologic outcomes. The measles, mumps, and rubella vaccine is not associated with autism. Vaccines are associated with local reactions, such as pain and erythema. The rotavirus vaccine minimally increases the rate of intussusception, whereas other vaccines minimally increase the risk of syncope. Although immunization with the human papillomavirus vaccine is recommended for all boys and girls, vaccination rates remain low. Physicians should guide parents to credible resources if they are considering vaccine refusal. If a recommended vaccine is refused, proper documentation is essential. The Vaccine Adverse Event Reporting System and National Vaccine Injury Compensation Program track adverse events and allow compensation for documented harms from vaccinations.
Topics: Adverse Drug Reaction Reporting Systems; Chickenpox Vaccine; Health Knowledge, Attitudes, Practice; Humans; Measles-Mumps-Rubella Vaccine; Preservatives, Pharmaceutical; Thimerosal; United States; Vaccination; Vaccines
PubMed: 28671426
DOI: No ID Found -
Molecular Autism 2017According to recent evidence, up to 40-50% of variance in autism spectrum disorder (ASD) liability might be determined by environmental factors. In the present paper, we... (Review)
Review
BACKGROUND
According to recent evidence, up to 40-50% of variance in autism spectrum disorder (ASD) liability might be determined by environmental factors. In the present paper, we conducted a review of systematic reviews and meta-analyses of environmental risk factors for ASD. We assessed each review for quality of evidence and provided a brief overview of putative mechanisms of environmental risk factors for ASD.
FINDINGS
Current evidence suggests that several environmental factors including vaccination, maternal smoking, thimerosal exposure, and most likely assisted reproductive technologies are unrelated to risk of ASD. On the contrary, advanced parental age is associated with higher risk of ASD. Birth complications that are associated with trauma or ischemia and hypoxia have also shown strong links to ASD, whereas other pregnancy-related factors such as maternal obesity, maternal diabetes, and caesarian section have shown a less strong (but significant) association with risk of ASD. The reviews on nutritional elements have been inconclusive about the detrimental effects of deficiency in folic acid and omega 3, but vitamin D seems to be deficient in patients with ASD. The studies on toxic elements have been largely limited by their design, but there is enough evidence for the association between some heavy metals (most important inorganic mercury and lead) and ASD that warrants further investigation. Mechanisms of the association between environmental factors and ASD are debated but might include non-causative association (including confounding), gene-related effect, oxidative stress, inflammation, hypoxia/ischemia, endocrine disruption, neurotransmitter alterations, and interference with signaling pathways.
CONCLUSIONS
Compared to genetic studies of ASD, studies of environmental risk factors are in their infancy and have significant methodological limitations. Future studies of ASD risk factors would benefit from a developmental psychopathology approach, prospective design, precise exposure measurement, reliable timing of exposure in relation to critical developmental periods and should take into account the dynamic interplay between gene and environment by using genetically informed designs.
Topics: Autism Spectrum Disorder; Delivery, Obstetric; Environmental Exposure; Female; Humans; Meta-Analysis as Topic; Metals, Heavy; Parents; Pregnancy; Prospective Studies; Risk Factors; Systematic Reviews as Topic
PubMed: 28331572
DOI: 10.1186/s13229-017-0121-4 -
Acta Neurobiologiae Experimentalis 2010
Topics: Acetaminophen; Amygdala; Autistic Disorder; Child; Child, Preschool; Exploratory Behavior; Gastrointestinal Tract; Humans; Mercury; Motor Activity; Receptor, Serotonin, 5-HT2A; Thimerosal; Vaccination
PubMed: 20642023
DOI: 10.55782/ane-2010-1783 -
Clinica Chimica Acta; International... Apr 2015Thimerosal (or Thiomersal) is a trade name for an organomercurial compound (sodium ethyl-mercury (Hg) thiosalicylate) that is 49.55% Hg by weight, which rapidly... (Review)
Review
INTRODUCTION
Thimerosal (or Thiomersal) is a trade name for an organomercurial compound (sodium ethyl-mercury (Hg) thiosalicylate) that is 49.55% Hg by weight, which rapidly decomposes in aqueous saline solutions into ethyl-Hg hydroxide and ethyl-Hg chloride. Developed in 1927, it has been and is still being used as a preservative in some cosmetics, topical pharmaceuticals, and biological drug products, including vaccines. Concerns have been voiced about its use because it is toxic to human cells. Although it is banned in several countries, it continues to be added to some vaccines in the United States and many vaccines in the developing world.
DISCUSSION
This critical review focuses on the clinical, epidemiological, and biochemical studies of adverse effects from Thimerosal in developing humans. This review will include research that examines fetal, infant, and childhood death; birth defects; neurodevelopmental testing deficits in children; and neurodevelopmental disorders (attention deficit/hyperactivity disorder, autism spectrum disorder, tic disorder, and specific developmental delays). The review will also look at the research that examined the outcomes of acute accidental ethyl-Hg poisoning in humans. The studies that examine the underlying biochemical insights into the neuronal cellular damage will also be explored.
CONCLUSION
The culmination of the research that examines the effects of Thimerosal in humans indicates that it is a poison at minute levels with a plethora of deleterious consequences, even at the levels currently administered in vaccines.
Topics: Growth and Development; Humans; Thimerosal
PubMed: 25708367
DOI: 10.1016/j.cca.2015.02.030 -
Influenza and Other Respiratory Viruses Nov 2009Few prospective studies of inactivated split virion influenza vaccine have been conducted in infants and children. Our objective was to evaluate the safety,...
OBJECTIVE
Few prospective studies of inactivated split virion influenza vaccine have been conducted in infants and children. Our objective was to evaluate the safety, reactogenicity and immunogenicity of a thimerosal-free inactivated influenza vaccine (Fluvax; CSL Limited, Parkville, Australia) in children aged 6 months to <9 years.
METHODS
A prospective, open-label, phase III clinical trial was conducted in 298 healthy children previously unvaccinated with influenza, commencing in the Southern Hemisphere 2005 autumn. Participants were divided into two groups (Group A: > or =6 months to <3 years; Group B: > or =3 years to <9 years), and received two doses of the 2005 vaccine, and one dose of the 2006 vaccine one year later (Group A: 0.25 ml per dose; Group B: 0.5 ml per dose). Vaccine safety and reactogenicity was evaluated for 30 days after each dose. Immunogenicity was assessed using hemagglutination inhibition and single radial hemolysis assays.
RESULTS
There were no withdrawals due to adverse events (AEs). The majority of solicited local and systemic AEs were of mild severity. A maximum intensity of severe was reported for injection site pain and fever by only 3.0% and 3.4% of participants, respectively. The vaccine was immunogenic for all antigens, with > or =95% of both younger and older children achieving seroprotection after dose 2.
CONCLUSIONS
This thimerosal-free inactivated influenza vaccine had a favorable safety profile and was immunogenic in children aged > or =6 months and <9 years. Primary and booster vaccination produced consistently immunogenic responses including in children under 3 years of age receiving 0.25 ml doses of vaccine.
Topics: Antibodies, Viral; Australia; Child; Child, Preschool; Drug-Related Side Effects and Adverse Reactions; Excipients; Female; Fever; Hemagglutination Inhibition Tests; Humans; Immunization, Secondary; Infant; Influenza Vaccines; Influenza, Human; Male; Pain; Thimerosal; Vaccines, Inactivated
PubMed: 19903213
DOI: 10.1111/j.1750-2659.2009.00108.x -
International Journal of Environmental... Aug 2013Autism spectrum disorder (ASD) is a neurological disorder in which a significant number of the children experience a developmental regression characterized by a loss of... (Review)
Review
Autism spectrum disorder (ASD) is a neurological disorder in which a significant number of the children experience a developmental regression characterized by a loss of previously acquired skills and abilities. Typically reported are losses of verbal, nonverbal, and social abilities. Several recent studies suggest that children diagnosed with an ASD have abnormal sulfation chemistry, limited thiol availability, and decreased glutathione (GSH) reserve capacity, resulting in a compromised oxidation/reduction (redox) and detoxification capacity. Research indicates that the availability of thiols, particularly GSH, can influence the effects of thimerosal (TM) and other mercury (Hg) compounds. TM is an organomercurial compound (49.55% Hg by weight) that has been, and continues to be, used as a preservative in many childhood vaccines, particularly in developing countries. Thiol-modulating mechanisms affecting the cytotoxicity of TM have been identified. Importantly, the emergence of ASD symptoms post-6 months of age temporally follows the administration of many childhood vaccines. The purpose of the present critical review is provide mechanistic insight regarding how limited thiol availability, abnormal sulfation chemistry, and decreased GSH reserve capacity in children with an ASD could make them more susceptible to the toxic effects of TM routinely administered as part of mandated childhood immunization schedules.
Topics: Animals; Child; Child Development Disorders, Pervasive; Glutathione; Humans; Mercury; Oxidation-Reduction; Preservatives, Pharmaceutical; Risk Factors; Sulfhydryl Compounds; Thimerosal; Vaccination; Vaccines
PubMed: 23965928
DOI: 10.3390/ijerph10083771 -
International Journal of Environmental... Jan 2023Although the molecular mechanisms underlying methylmercury toxicity are not entirely understood, the observed neurotoxicity in early-life is attributed to the covalent... (Review)
Review
Although the molecular mechanisms underlying methylmercury toxicity are not entirely understood, the observed neurotoxicity in early-life is attributed to the covalent binding of methylmercury to sulfhydryl (thiol) groups of proteins and other molecules being able to affect protein post-translational modifications from numerous molecular pathways, such as glutamate signaling, heat-shock chaperones and the antioxidant glutaredoxin/glutathione system. However, for other organomercurials such as ethylmercury or thimerosal, there is not much information available. Therefore, this review critically discusses current knowledge about organomercurials neurotoxicity-both methylmercury and ethylmercury-following intrauterine and childhood exposure, as well as the prospects and future needs for research in this area. Contrasting with the amount of epidemiological evidence available for methylmercury, there are only a few in vivo studies reporting neurotoxic outcomes and mechanisms of toxicity for ethylmercury or thimerosal. There is also a lack of studies on mechanistic approaches to better investigate the pathways involved in the potential neurotoxicity caused by both organomercurials. More impactful follow-up studies, especially following intrauterine and childhood exposure to ethylmercury, are necessary. Childhood vaccination is critically important for controlling infectious diseases; however, the safety of mercury-containing thimerosal and, notably, its effectiveness as preservative in vaccines are still under debate regarding its potential dose-response effects to the central nervous system.
Topics: Humans; Thimerosal; Methylmercury Compounds; Preservatives, Pharmaceutical; Mercury; Vaccines; Neurotoxicity Syndromes; Sulfhydryl Compounds
PubMed: 36673825
DOI: 10.3390/ijerph20021070 -
Indian Journal of Medical Ethics 2014When addressing toxins, one unmistakable parallel exists between biology and politics: developing children and developing nations are those most vulnerable to toxic... (Review)
Review
When addressing toxins, one unmistakable parallel exists between biology and politics: developing children and developing nations are those most vulnerable to toxic exposures. This disturbing parallel is the subject of this critical review, which examines the use and distribution of the mercury (Hg)-based compound, thimerosal, in vaccines. Developed in 1927, thimerosal is 49.55% Hg by weight and breaks down in the body into ethyl-Hg chloride, ethyl-Hg hydroxide and sodium thiosalicylate. Since the early 1930s, there has been evidence indicating that thimerosal poses a hazard to the health of human beings and is ineffective as an antimicrobial agent. While children in the developed and predominantly western nations receive doses of mostly no-thimerosal and reduced-thimerosal vaccines, children in the developing nations receive many doses of several unreduced thimerosal-containing vaccines (TCVs). Thus, thimerosal has continued to be a part of the global vaccine supply and its acceptability as a component of vaccine formulations remained unchallenged until 2010, when the United Nations (UN), through the UN Environment Programme, began negotiations to write the global, legally binding Minamata Convention on Hg. During the negotiations, TCVs were dropped from the list of Hg-containing products to be regulated. Consequently, a double standard in vaccine safety, which previously existed due to ignorance and economic reasons, has now been institutionalised as global policy. Ultimately, the Minamata Convention on Hg has sanctioned the inequitable distribution of thimerosal by specifically exempting TCVs from regulation, condoning a two-tier standard of vaccine safety: a predominantly no-thimerosal and reduced-thimerosal standard for developed nations and a predominantly thimerosal-containing one for developing nations. This disparity must now be evaluated urgently as a potential form of institutionalised discrimination.
Topics: Developing Countries; Drug and Narcotic Control; Healthcare Disparities; Humans; International Law; Mercury; Moral Obligations; Social Discrimination; Thimerosal; United Nations; Vaccines
PubMed: 25101548
DOI: 10.20529/IJME.2014.054 -
BioMed Research International 2014There are over 165 studies that have focused on Thimerosal, an organic-mercury (Hg) based compound, used as a preservative in many childhood vaccines, and found it to be... (Review)
Review
There are over 165 studies that have focused on Thimerosal, an organic-mercury (Hg) based compound, used as a preservative in many childhood vaccines, and found it to be harmful. Of these, 16 were conducted to specifically examine the effects of Thimerosal on human infants or children with reported outcomes of death; acrodynia; poisoning; allergic reaction; malformations; auto-immune reaction; Well's syndrome; developmental delay; and neurodevelopmental disorders, including tics, speech delay, language delay, attention deficit disorder, and autism. In contrast, the United States Centers for Disease Control and Prevention states that Thimerosal is safe and there is "no relationship between [T]himerosal[-]containing vaccines and autism rates in children." This is puzzling because, in a study conducted directly by CDC epidemiologists, a 7.6-fold increased risk of autism from exposure to Thimerosal during infancy was found. The CDC's current stance that Thimerosal is safe and that there is no relationship between Thimerosal and autism is based on six specific published epidemiological studies coauthored and sponsored by the CDC. The purpose of this review is to examine these six publications and analyze possible reasons why their published outcomes are so different from the results of investigations by multiple independent research groups over the past 75+ years.
Topics: Autistic Disorder; Humans; Infant; Preservatives, Pharmaceutical; Thimerosal; United States; Vaccines
PubMed: 24995277
DOI: 10.1155/2014/247218 -
Actas Dermo-sifiliograficas Jun 2022Rosacea is a chronic acneiform skin disorder in which impaired skin barrier function can lead to sensitization to allergens. We aimed to analyze contact allergies in our...
BACKGROUND AND OBJECTIVE
Rosacea is a chronic acneiform skin disorder in which impaired skin barrier function can lead to sensitization to allergens. We aimed to analyze contact allergies in our patients with rosacea.
MATERIAL AND METHODS
Retrospective cohort study of all patients who underwent patch testing in our skin allergy clinic between May 1991 and May 2019.
RESULTS
A total of 200 patients with rosacea were referred to our clinic for patch testing during the study period; they represented 2.1% of all patch tested patients in the period. Eighty-one percent were women (mean age, 44.7years). At least 1positive patch test was recorded for 46.5%; 15% were of current relevance. The most frequent positive reaction was to nickel (26%), followed by cobalt chloride (6.5%), isothiazolinones (6%), p-phenylenediamine (5.5%), fragrance mixII (5%), and thimerosal (3.5%). The most common currently relevant patch test reactions were to isothiazolinones in 10 of the 200 patients (5%); to phenylenediamine, fragrance mixII, and toluensulfonamide formaldehyde resin in 4 patients (2%) each; and to tixocortol and fragrance mixI in 2 patients (1%) each. The allergen groups most often implicated were metals (of current relevance in 12.6%) and drugs (of current relevance in 25.8%). Preservatives and fragrances were the next most common allergen groups, and 70.8% and 43.7% of the positive reactions in these groups, respectively, were of current relevance. Cosmetics were the most frequent source of sensitization, followed by topical medications - notably corticosteroids and antifungal agents.
CONCLUSIONS
We emphasize the high prevalence of allergic contact dermatitis in patients with rosacea, a finding which supports patch testing, especially if eruptions worsen when these patients use cosmetics and topical medications.
Topics: Adult; Allergens; Cosmetics; Dermatitis, Allergic Contact; Female; Glucocorticoids; Humans; Male; Patch Tests; Retrospective Studies; Rosacea
PubMed: 35288101
DOI: 10.1016/j.ad.2022.02.026