Abstract
A growing number of vaccines are administered at the same time or in close succession, increasing the complexity of assessing vaccine safety. Individual vaccines are assumed to have no other effect than protection against the targeted pathogen, but vaccines also have nonspecific and interactive effects, the outcomes of which can be beneficial or harmful. To date, no controlled trials and very few observational studies have determined the impact of vaccination schedules on overall health. The balance of the risks and benefits from mass vaccination therefore remains uncertain. Recent studies worryingly suggest links between multiple vaccinations and increased risks of diverse multisystem health problems, including allergies, infections, and neuropsychiatric or neurodevelopmental disorders. Here, we propose that, in susceptible persons, multiple vaccinations activate the retinoid cascade and trigger apoptotic hepatitis, leading to cholestatic liver dysfunction, in which stored vitamin A compounds (retinyl esters and retinoic acid) enter the circulation in toxic concentrations; this induces endogenous forms of hypervitaminosis A, with the severity of adverse outcomes being directly proportional to the concentration of circulating retinoids. In very low concentrations, vitamin A and its major metabolite retinoic acid contribute to immune function and to the process of immunization, whereas excess vitamin A increases the risk of adverse events, including common “side-effects” as well as chronic adverse outcomes. The increasing rates of allergy, ear infections, and neurodevelopmental disorders (NDDs) in countries with high rates of vaccination could be related to mass vaccination and to its impact on liver function and vitamin A metabolism, collectively representing endogenous manifestations of hypervitaminosis A. Further studies of health outcomes in vaccinated and unvaccinated groups are urgently needed, to increase understanding of the pathophysiology and treatment of vaccine injury, to identify the risk factors and screen for vaccine injury, to inform public health policy on potential hazards related to vaccination schedules, and to optimize the safety and benefits of vaccines.
Highlights
Other concerns of stakeholders related to vaccines include the absence of studies on the health outcomes of fully vaccinated versus partially vaccinated and unvaccinated children; the paucity of studies on the immunization schedule itself; the lack of information on the effects of multiple vaccinations given at a single visit [26]; and whether vaccines could be contributing to the unexplained increases in the rates of allergy, asthma, and neurodevelopmental disorders (NDDs) [27,28,29,30]
Retinoic acid levels and synthesis were increased, as shown by the elevated expression of retinaldehyde dehydrogenases [53]. These findings suggest that increased Retinoic Acid Receptor- (RAR)-mediated signaling in allergen-induced dermatitis may contribute to the development and/or maintenance of allergic skin diseases
Many parents are questioning the safety of vaccines, leading the World Health Organization (WHO) in 2019 to declare “vaccine hesitancy” as one of the 10 biggest threats to global health, potentially reversing the progress made in tackling vaccine-preventable diseases [111]
Summary
Vaccines given to infants and young children in the first two decades of the 20th century are estimated to have prevented 322 million illnesses, 21 million hospitalizations, and 732,000 deaths during their lifetimes [1]. Most awards result from a negotiated settlement between the parties in which it is concluded that the outcome and the circumstances match those of previous cases, as set forth in the Vaccine Injury Table [15] The data for such cases derive from reports to the Vaccine Adverse Effects Reporting System (VAERS), filed voluntarily by physicians or parents. Another tracking system for vaccine adverse effects, the Vaccine Safety Datalink (VSD), is a collaboration between the CDC and nine healthcare organizations [16]. As vaccinations are a covered benefit of the VSD health plans, and vaccine coverage rates are higher than national coverage estimates, this highly vaccinated population has limited numbers of unvaccinated children for comparison purposes [17]
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