Healthy Living: A Shot or Not
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It’s not a choice. If you live in Connecticut and you want your kids to go to school, childhood vaccines are mandated. And you better believe the vaccine schedule from birth to age 6—as laid out by the federal government’s Centers for Disease Control (CDC)—is a full dance card. There’s HepB, given in three doses between birth and 18 months, designed to prevent the liver infection Hepatitis B; four doses of PCV between 2 and 15 months, to guard against bacterial pneumonia; DTaP in five doses between 2 months and 6 years, for diptheria, whooping cough and tetanus; two doses of MMR (measles, mumps, rubella), four doses of Hib (Haemophilus influenzae, which can cause meningitis), four of IPV (polio) . . . in short, if your pediatrician follows CDC recommendations to the letter, your child can expect up to roughly three dozen vaccines as protection against 14 different communicable diseases that, in generations past, often led to hospitalization, disability and sometimes death.
Baby-boomer grandparents who remember that sucking on a sugar-cube dosed with polio vaccine was once considered the greatest triumph of science next to the 1969 moon landing would be astonished by the regimen young parents are now expected to keep in their infant’s first 18 months. This includes several doctor’s office visits requiring as many as five or six shots each. Still, that’s all to the good, right? After all, mass vaccination campaigns have eradicated smallpox and nearly eradicated polio—a fearsome crippler and killer of young children in the first half of the 20th century—in our lifetimes, while keeping other viral and bacterial threats from blossoming into epidemics.
Alas, these days it seems there’s little joy in Wellville. Along with all of our public-health successes has come fear, particularly of the side effects and allergic reactions some vaccines can produce. While these are limited mostly to swelling at the injection site, fever and/or mild physical discomfort, on rare occasions (one in 100,000) something more serious happens—seizures, for example. Such events have led to loud calls from the populace for greater “safety.” But safety is a relative concept, says Dr. Steven Novella, assistant professor of neurology at Yale School of Medicine and senior editor of the blog Science-Based Medicine. “Certainly, not all vaccines are equally safe,” he says. “But all vaccines that are currently administered have greater benefits than risks to the individual. That’s the bar that we set before we allow vaccines on the market and recommend them for use, whether for routine prevention or targeted populations.”
Two of the greatest vaccine fears include the potential side effects of certain additives, the main one being aluminum hydroxide, used as an adjuvant to improve the efficacy of many vaccines (although research indicates that babies get more aluminum in their daily formula), and the possibility of “vaccine overload” overwhelming an infant’s immune system. Jeffrey S. Gerber and Paul A. Offit—of the Children’s Hospital of Philadelphia’s Division of Infectious Diseases—debunked the latter in a 2009 article in the journal Clinical Infectious Diseases, pointing out that infants’ immune systems can, and do, respond to thousands of pathogenic threats simultaneously. In addition, improvements in vaccine design in recent years have actually lightened the immunologic load, so that the number of active components in 14 vaccines is actually less than 10 percent of the components present in the seven vaccines given in 1980.
A far greater worry to the medical community is the way such fears can disrupt vaccine compliance, particularly when immunization numbers drop to the point that they threaten “herd immunity”—the delicate balance that’s achieved when the percentage of the vaccinated population in a community is high enough to protect those with immune deficiencies (or other relevant health problems) from a disease outbreak. This percentage varies from disease to disease depending on how contagious it is; for instance, for a community to achieve herd immunity from the measles, vaccination rates must top 90 percent. Connecticut, it should be noted, has a virtuously high rate of vaccine compliance: For the last 15 years, the state has ranked in the top five states for on-time childhood immunizations—and in 2008, CDC officials visited Hartford for a congratulatory ceremony. This performance has been enhanced by our adoption in 1998 of a system for all newborns called the Connecticut Immunization Registry and Tracking System (CIRTS).
Other parts of the world have not fared as well. The reason polio has not yet been eradicated—though it’s no longer endemic in the United States—is a failed vaccination campaign in northern Nigeria early in the last decade. “At the time, Muslim clerics started spreading a scare about the vaccine, saying that it was a conspiracy by Western medicine to spread polio and AIDS,” Novella says. By 2006, Nigeria was determined to be the source of over half of all new polio cases worldwide.