Autoimmunity, allergies, and asthma: A relationship to vaccines?

Over the past few decades, there is an increasing trend of parents refusing or requesting an alternative regimen for their child's routine vaccinations. Though previously considered to be most prevalent in areas with limited health care resources or among younger parents with limited insight into the importance of vaccinations, a growing group of dissenters are parents who are older, educated, and more affluent individuals concerned about the purported dangers/risk of routine vaccinations. The focus of this chapter is to review specific concerns that have been raised regarding the relationship between vaccinations and both atopy and autoimmunity. Recent studies have focused on the potential role that various components of the immune system, including T-regulatory cells, toll-like receptors, and dendritic cells, may play in the hygiene hypothesis theory and in regulating the development of autoimmunity and atopy. Despite the theory that a limited exposure to pathogens in early life predisposes to autoimmunity and atopy, there is a paucity of evidence to support a higher incidence of atopic and autoimmune conditions in vaccinated children compared to their unvaccinated counterparts. One possible explanation for this negative association may be the inability of vaccinations to completely eliminate pathogenic microbial exposure during childhood, nor was this ever an intention. From the standpoint of exacerbating disease activity by vaccinating patients with underlying autoimmune conditions, supportive evidence is found only with certain vaccinations in limited disease states. Nevertheless, providers must evaluate this potential risk against protecting patients at high risk of infectious complications due to intrinsic immune dysregulation and immunomodulator therapy. Providers may face challenging encounters with parents who are sincerely motivated by concerns about their child's welfare and reluctant or opposed to current vaccination strategies due to underlying misconceptions. It is imperative that health care providers serve as patient advocates, be receptive to discuss parents' concerns, allay unwarranted fears, and help resolve misconceptions regarding vaccine safety.