Childhood Vaccines: A Case of Collective Amnesia

Children in Nigeria line up to receive the smallpox vaccine, 1968.
In 1979, the World Health Organization (WHO) declared
the global eradication of smallpox and recommended
that all countries cease vaccination. 
Source: CDC

Not long ago, I was in the bleachers at one of my son's baseball games. It was one of those ordinary, and therefore quite wonderful, evenings. Nice weather, decent sports action, no place I'd rather be. Out of the corner of my eye, I saw a dad and two kids walk by and then stand by the bleachers to watch the game. Again, not unusual. However, what caused me to do a double take was the oldest child's extreme skin condition.

All of this child's visible skin was covered with angry-looking, red sores. Arms, hands, face, neck. The sores looked vaguely familiar, and then it hit me: This kid was walking around with chicken pox. Not trusting my own diagnosis, I leaned over to a physician/baseball mom near me and said, "Does that kid have chicken pox?" She nodded her head in affirmation and said, "I know his family. They don't vaccinate, and they infected him on purpose at a 'chicken pox party'."

I had to think about that for awhile.

From what I could tell, most of the kid's pox were scabbed over, which meant they weren't infectious. But I did notice some newer pox that looked more like blisters, meaning that they were potentially infectious. Even though I confess to a somewhat irrational cringe moment at being so close to this kid, I wasn't really worried about my own health. After all, I had a raging case of chicken pox in elementary school that rendered me immune. But looking around the bleachers, I saw a couple of grandparents and a baby. And that's when my noncommittal response to the chicken pox family turned into a more judgmental one. After all, the grandparents were at risk of developing chicken pox or activating shingles because of their aging immune systems, and the baby was definitely at risk because the chicken pox vaccine is not given until four or five years of age. And for all I knew, any one of the seemingly healthy middle-aged parents in attendance could have been immunocompromised from cancer treatment, HIV infection, or other conditions. Whatever thoughts I had about the chicken pox family's beliefs toward vaccination quickly became secondary to what I thought of this family being in a public venue with a perhaps-active and easily transmissible infectious disease, no matter how "certain" they were of the child's infection status.

Unfortunately, judging from vaccination trends, we can expect more and more of these exposures.

This past week, media outlets across the country carried news of the whooping cough outbreak in Washington state. The outbreak is huge - well over 1,000 cases, and one that

"could surpass the toll of any year since the 1940s, before a vaccine went into wide use," according to public health officials interviewed by The New York Times. 

The numbers are probably higher because many people with mild disease do not get a diagnosis. Further, the state is so strapped for cash that it is recommending foregoing the $400 diagnostic test and just prescribing antibiotics to those with the hallmark symptoms and exposure patterns, causing speculation that only 1 in 5 infections are being recorded.

The outbreak is directly attributable to that fact that families of 6% of school-age children in Washington have opted out of some or all of the recommended immunizations. That 6% is over the tipping point where even people with some degree of immunity through vaccination can have elevated risk of getting the disease. This is especially germane to whooping cough. Researchers have reformulated the whooping cough vaccine in recent years to reduce its side effects. As a consequence, the new vaccine is not as effective as older versions were, making the concept of herd immunity even more important for this particular disease.

In other words, individuals who received vaccinations and trusted others to do the same in order to keep herd immunity strong, were totally screwed over by families who decided to not only put their kids at risk, but also other people's kids (and grandparents, and so on).

I've written about this issue before, from an international perspective here and a link to a vaccine expert here. It is so concerning that we are exiting, voluntarily, the era of disease prevention through vaccination. Not because the vaccines don't work. No, modern vaccines work extremely well. So well, in fact, that younger generations do not remember how deadly or disfiguring certain diseases can be because they have never experienced them. If vaccination rates continue to slide, though, it's fairly clear that we all - regardless of our own vaccination status - will pay the price, either through disease or higher health care costs.

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And So It Begins

CDC, Public Health Image Library

I am fortunate to have the Dengue Vaccine Initiative as a client. Through this group, I have traveled the world, meeting with doctors and scientists, working to lay the groundwork for a coming vaccine against dengue fever. As our work has progressed from discussing issues with surveillance and diagnostics, we have moved into communication issues - the need to raise awareness among politicians, healthcare professionals, and consumers of a coming vaccine, and the lifesaving (and cost saving) benefits such a vaccine will confer on countries in which dengue sickens hundreds of thousands of people annually.

One of the issues that confronts us is anti-vaccine activism. This is a worldwide phenomenon. Activists' concerns range from what we see in the United States - concerns about autism - but also include cultural-specific worries. For example, in Argentina, a branch of the Catholic church warns that vaccines will cause women to abort their fetuses. In parts of Asia with large Muslim populations, there are concerns that some vaccines are made with cells from dogs or from pork gelatin. It is stiff opposition that can usually be satisfied with factual answers.

But overall, countries outside of the United States are hungry for vaccines. When PATH and The Gates Foundation worked with India to quickly distribute a vaccine against Japanese Encephalitis - a mosquito-borne disease common in rural areas that causes paralysis and death in high numbers - they were able to vaccinate 32 million children in a year and a half because people were desperate for protection. From the safety of the United States, it may be difficult to understand that polio still cripples hundreds of children in India each year or that measles killed over 160,000 people worldwide in 2008. We have become used to a childhood without those terrible diseases.

This is likely a generational issue. My mother remembers having to stay indoors during the hot summer months, away from other people, when polio epidemics were raging throughout the countryside. Isolating her family was the only way my grandmother could protect her children.  As a kid, probably around 3 years old, I stood in line in a school gymnasium - a very long line snaking around the gym and outside the door - to receive a dose of the Sabin polio vaccine on a sugar cube. I have a fuzzy memory of the darkness of the gym but really what I remember is the solemnity of the occasion. Granted, it was a long time ago, but I like to think I was feeling the resolve of all those moms who brought their kids in to protect them against the seasonal fear of fever, paralysis, iron lungs. And I, too, am part of the generational divide: I have a round and dimpled scar on my upper left arm from a smallpox vaccination, a badge that signifies me as a woman of a certain age, to be sure, because today's kids don't get vaccinated against smallpox because it is no longer a threat.

Unlike smallpox, most vaccine-preventable diseases are not eradicated, just kept under control. That control, however, is tenuous because we rely on herd immunity - keeping a high proportion of our population vaccinated in order to prevent diseases - to protect our society. In other words, all those families who don't vaccinate their kids can be reasonably assured that their kids won't get childhood diseases because so many other families do vaccinate their kids. However, there is always a tipping point, where diseases can race through unvaccinated kids and infect those with partial immunity, such as the elderly who have lost their immunity, children who have not received boosters, or infants who have not received vaccinations.   Recent news carried a report of a death from whooping cough, not in Nigeria, not in Bangladesh, not in Cambodia. But here, in the great state of California. And it's the 10th one in California this year. This infant's death is attributed to families not vaccinating their children against pertussis, thus allowing this potentially deadly disease to spike again.

Recent estimates show that over 7.0% of children entering kindergarten in Marin county, a wealthy suburb of San Francisco, have waivers exempting them from childhood vaccinations based on their parents' beliefs. A private school in San Diego reports that 51% of its kindergartners had such exemptions. These are shockingly high numbers because once these percentages reach the tipping point, we will lose our herd immunity. And evidence is growing that we are approaching that that point: For each one percent increase in exemptions at a school, the risk of having a pertussis outbreak went up by 12%, a 2000 study in the Journal of the American Medical Association found. The study, which was conducted in Colorado, also found that at least 11% of the vaccinated children in measles outbreaks were infected through contact with somebody who was exempt.

Epidemics start with a whisper. A case of pertussis here, a few cases of measles there. But make no doubt about it: we are on the cusp of an epidemic of many diseases that we thought we left behind. What is it about human nature that makes us reinvent the wheel again and again? If you don't want to vaccinate your kids, I recommend you travel to poor countries around the world. Tell a mother who fears seasonal outbreaks of diseases that you turned down the opportunity to vaccinate your kids against those diseases. Of course, many who don't vaccinate their kids point out that we don't live in developing countries, and that many vaccine-preventable diseases are rare in the United States. That is true. These diseases are rare because people vaccinate their kids. And they won't stay rare if we don't.

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