A recent measles outbreak, radiating throughout the U.S. from an imported case at Disney World in Anaheim, California, has captivated national attention. As of February, 2015, there had been over 140 recorded cases, with the potential of rising considerably higher. Although the beginning of this outbreak originated from the “Magic Kingdom”, past outbreaks began in less colorful or even multiple locations, but still had the same remarkable spread (over 600 U.S. cases in 2013).
Measles is one of number of childhood diseases that can be successfully prevented with vaccinations. The MMR (Mumps-Measles-Rubella) vaccine, usually given at one year and four years of age, offers lifelong protection to the recipients. Those born prior to 1957 are considered immune because of the widespread nature of the disease prior to the introduction of a highly effective vaccine.
Since most children are vaccinated, what are the problems peculiar to measles? First, measles was declared eradicated in the United States in 2000, which means there were no circulating indigenous cases. Worldwide, however, the situation is far different, with many areas of incomplete vaccination and ongoing cases. Under these circumstances, imported cases are always possible, even inevitable.
Second, measles is only one of several highly contagious viruses that are truly airborne. Many other infections are droplet borne (such as influenza or tuberculosis), but those droplets can only extend out approximately three feet before gravity pulls them to the ground where they are less likely to cause infection. Measles, on the contrary, floats in the air and can do so for hours. Anyone entering in a room or public space where an infected individual passed through can inhale the virus and become infected. In fact, if 100 unvaccinated people walked through a room where a measles patient had been in the recent past, 90 of them would come down with measles. There are only a few such airborne viral threats, including smallpox, which has fortunately been eliminated.
Third, there is a growing reservoir of children in the U.S. who have not been vaccinated because of parental opposition. Misguided and ill-informed adults exaggerate the risks of vaccination and minimize the risks of measles and other diseases, often because they have never seen cases in their lifetimes. In reality, measles—far from a harmless childhood disease—can result in pneumonia, encephalitis (inflammation of the brain) and death. Around 25% of U.S. citizens infected with measles will require hospitalization and 1/500 could die.
Because of these three facts (the highly contagious nature of the virus, the overseas reservoir of cases and the growing group of unvaccinated children in the United States), measles remains a serious threat. Vaccines can have some side effects, mostly mild and transitory, but the decision not to vaccinate ignores scientific evidence and defies common sense. Protect your children and others by vaccination, you owe to your loved ones and to your community.