Arguably the greatest success story in public health, vaccines demonstrate the triumph of human achievement over disease. But during the last decade or so, vaccine risks have gotten more attention than the diseases they prevent.
Before I retired from neonatal intensive care, persuading parents to immunize their infants was getting to be the most difficult part of my job. It felt bizarre to be unsuccessfully promoting vaccines to parents in a room full of machines so advanced and personnel so highly trained that we can save a baby so tiny it resembles a baby bird fallen from the nest.
When vaccine rates drop, "herd immunity" is compromised and diseases return. Take, for example, measles. The Centers for Disease Control and Prevention (CDC) estimates that, prior to the 1960s, about 3 to 4 million Americans got measles each year. Of those people, 400 to 500 died and 48,000 were hospitalized. A vaccine was developed and a campaign began in 1963. Both were so effective that, with 86 cases in the year 2000, measles was declared eliminated in this country. Yet in 2014, the CDC reported 668 cases.
How did we snatch defeat from the jaws of victory?
* Certain diseases no longer seem real to us. Before systematic vaccination, diseases like polio, measles, mumps, tetanus, and whooping cough were a source of great morbidity, tragedy, and fear. Two generations of Americans have no experience with those diseases.
* A 1998 study published in The Lancet started a worldwide vaccine scare. The study claimed to identify a link between the vaccine for measles, mumps, and rubella (MMR) and the onset of autism. In 2010, The Lancet retracted the article and 10 of the 13 authors have denounced it, but the damage had been done.
* A high degree of skepticism exists. A research letter in the March 2014 JAMA Internal Medicine reported that 49% of Americans surveyed indicated that the federal government, corporations (especially pharmaceutical companies), or both are involved in at least one conspiracy to cover up health information. Public skepticism plays a key role in the persistence of misinformation, and conspiracist beliefs are correlated with health behaviors such as avoiding vaccines.
* Misinformation is resistant to correction. A 2012 literature survey by Lewandowsky and colleagues concluded that people more readily accept statements that are consistent with their beliefs. Conversely, suspending belief requires "a high degree of attention" and "considerable implausibility of the message." It's easier to trust a myth if it supports existing convictions than to reject information that requires energy to assess.
* A new breed of empowered patients has emerged with vast quantities of information at their fingertips. While there are proven benefits to well-informed patient engagement, many lay researchers are unable to distinguish unscientific from scholarly sources when searching for medical information via the Internet.
* The suggestion or pressure to vaccinate may be viewed as a power play or an attack on personal freedom. But the tension is misplaced. Society has a vested interest in keeping people safe and healthy, hence laws regarding crosswalks, seat belts, and texting while driving. Are pediatricians justified in closing their practices to children whose parents refuse to immunize? Absolutely. Are schools justified in requiring unvaccinated children to stay home after a measles exposure for 21 days (the length of time between exposure and the beginning of the rash and fever)? Of course.
An extensive grassroots movement contemptuous of science and government opposes systematic vaccination against deadly diseases. But those who choose not to get vaccinated serve as potential vectors of disease transmission to unsuspecting persons-especially to those who can't be immunized, such as immunosuppressed children and adults, or to infants who are too young. Maintaining community immunity is a job for all of us, not for some of us.