Measles, misinformation, and risk: personal belief exemptions and the MMR vaccine.

Abstract

Across the United States, children entering schools are required to get a series of vaccinations that includes the measles, mumps, and rubella (MMR) vaccine.1 Designed to prevent those three devastating childhood illnesses, the MMR vaccine has proven highly effective and low risk. By the year 2000, decades of the vaccine's use in the US led to the official elimination of measles in this country;2 during those decades, children had severe, vaccine-associated adverse reactions so infrequently that the Centers for Disease Control and Prevention (CDC) does not report them as causally linked.3 Nonetheless, a now-retracted 1998 paper linked the MMR vaccine with the development of autism. This paper set off the most-recent anti-vaccination movement—a wave of fear and mistrust of vaccines (and particularly of MMR) that persists in some communities to this day.4 Because of a clustering of such communities in affluent regions of California,5 epidemiological conditions in the state became favorable for a new, widespread outbreak of measles.6 Such an outbreak began at Southern California's Disneyland in early 2015.7 As the outbreak spread to 23 other states and the District of Columbia, it reignited debates about states' exemptions from their MMR mandates. Those exemptions fall into two categories: medical and non-medical. Generally, the latter category further divides into religious exemptions and philosophical exemptions; the latter of these often becomes the tool that anti-vaccine parents use to avoid MMR. Though only two states (California and Vermont) have entirely eliminated their philosophical exemptions in response to the Disneyland outbreak, several other states have at least considered either restriction or complete elimination of philosophical exemptions as a means to improve vaccination rates. In doing so, those states have sparked debates about the ethics of MMR immunization mandates and their exemptions. This paper first outlines some of the basic science around measles and the MMR vaccine. This science is essential to understanding the debates around the vaccine exemption laws. This paper then discusses the different types of exemption laws with a focus on who uses them. After summarizing the specific circumstances of the 2015 Disneyland outbreak, this paper considers the two main sides of the ethical debate around vaccine exemption. This consideration leads to the conclusion that states considering changes to their vaccine exemption laws should balance the concerns of both those who support and those who oppose vaccines. Striking that balance will be crucial to developing the right changes to the laws around the MMR vaccine—which will promote higher vaccination rates and prevent future harm to children from measles outbreaks.