This piece first appeared on March 2, 2008 in the San Diego Union-Tribune.
Childhood infectious diseases we thought had been relegated to the dustbin of history seem to be making a comeback. Why? Policy-makers, and concerned but misguided parents -- frightened by alarmist scare stories about vaccine-induced illnesses -- are responsible. State health authorities must change their policy, now.
A mini-epidemic of measles has been detected in San Diego, according to the latest issue of the Centers for Disease Control journal, _MMWR_, an early release bulletin warning physicians and other health care workers about the situation.
A seven-year-old boy whose parents had signed the simple form giving him a "personal belief exemption" from California's requirements for children to attend school, and was thus unprotected from measles, accompanied his family to Switzerland last month. Unfortunately, a measles epidemic was ongoing in that country, since only about 70% of Swiss schoolchildren get the requisite two-dose course. When the family got back to San Diego, the child became ill with fever, sore throat and eye irritation -- but nevertheless, he attended school. Although he developed a rash typical of measles, his visit to his pediatrician was not preceded by appropriate controls for contagious disease, nor was his visit to a lab for blood tests, nor his visit to a local ER for a fever of 104 degrees.
The boy's two siblings and then five classmates became ill. Subsequently, four additional children (three infants) who had shared the doctor's office during his visit took sick.
All the twelve sick infants and children detected so far were unvaccinated, thanks to California's highly flexible personal belief exemption policy. One of the infants had to be hospitalized. Case finding and high-intensity surveillance continue in the area, so the whole story may not have been written.
While measles has essentially been eradicated in the United States (except for "imported" cases, such as the one in San Diego), thanks to a successful mass-immunization program begun in the early 1960s, epidemics large and small have been documented every decade or so. These throwback epidemics were imported by unimmunized travelers and caused illness mainly -- but not exclusively -- among other unvaccinated people, including some adults.
Before the MMR (measles-mumps-rubella) vaccine, measles caused between 500,000 and 2 million illnesses and about 500 deaths in the United States each year. Several thousand among the sicker children sustained permanent brain damage from a virus complication, encephalitis. Pneumonia also can occur, especially among adults who contract measles, and can be lethal. Since the vaccine, annual cases number about 100, all of foreign origin and no deaths -- a major victory for public health.
All states allow exemptions from vaccination for a documented medical reason, and forty-eight permit religious exemption. But twenty-one, including California, allow for "philosophical" or personal belief exemptions, based on nothing more than a parent's say-so. Why do the various state public health authorities tolerate this bizarre superstition? Some would respond, because we must preserve our individual rights. But we modify those rights all the time to protect our neighbors' health. The Supreme Court has ruled that mandatory vaccinations against dangerous diseases do not constitute a violation of First Amendment rights to religious beliefs.
It must be remembered that even among vaccinated children, the risk of vaccine-preventable disease is markedly increased when classmates who lack immunity bring contagion into the classroom, since the protection afforded by vaccines is not quite 100%. A study in Colorado, which also permits personal belief exemptions, confirmed that the rate of measles and pertussis (whooping cough) among vaccinated children rose when the fraction of exempted children went up. Epidemics of pertussis in the northern states in 2004, measles in Indiana in 2005 and mumps in the Midwest in 2006, though concentrated in those with inadequate vaccine protection, nevertheless sickened substantial numbers of those who had been vaccinated.
Parents who fail to have their children vaccinated clearly put us all at risk rather than merely exercising their own (or by proxy their children's) rights. Why do they make this foolish, selfish decision? Usually out of superstitious fear of "vaccine-induced illness." While there is much chatter about this myth among parents' Web sites, avidly promoted by anti-vaccine zealots and some in the media who exploit these stories, the science is clear: Centers for Disease Control-recommended children's vaccines are safe. While nothing is 100% safe, including getting out of bed or crossing the street, the benefit-risk ratio for vaccines ranks them among the most beneficial therapies we have.
The fact that few of us now recall the scourge of childhood contagions should not make us complacent. California parents are being frightened by anti-chemical activists into believing that infinitesimal amounts of "contaminants" found in plastics, fire retardants and toy duckies may pose a risk for their children -- while real, vaccine-preventable illnesses are allowed to spread.
Parents who indulge their "personal beliefs" by skipping vaccinations go against medical science and put all children -- not just their own -- at risk. California's public health officials should revoke these pernicious exemptions as soon as possible to save children from new epidemics.