This article first appeared in the St. Louis Beacon, Jan. 17, 2011 - When Tom Wombacher first heard media reports about vaccines being potentially harmful and that some celebrities had stopped giving them to their children, he had his suspicions about the reliability of the information.
"I didn't think it was completely accurate," said the 33-year-old Overland resident whose son Nolan was born in last May.
Still, it gave him pause. He found himself surfing the internet on the topic.
"As a new parent, if I hear about something that sounds like it could be harmful to my kid, then of course I'm going to look into it," Wombacher said. "I did a little more research on my own and couldn't find anything conclusive that said that there was a problem."
Nolan was vaccinated on schedule, as planned.
But the news reports that fueled Wombacher's initial concern are part of a phenomenon that has been building for decades. Some parents are doubtful, even fearful, of vaccines. As anti-vaccine websites have proliferated and high-profile Hollywood stars have lent their names to the cause, some new mothers and fathers have begun to refuse vaccinations for their children. That's a choice that some physicians fear could lead to an increased number of outbreaks of diseases once thought conquered by the advance of modern medicine.
The dangers of a lower vaccination rate affect what researchers call "herd immunity." Widespread immunization helps protect the few un-inoculated persons in society against a given illness. But as vaccination numbers drop and more potentially vulnerable individuals circulate in the population, the community as a whole finds itself increasingly at risk of disease.
Such incidents are seen from time to time, for instance:
- In 2006, a mumps outbreak in the Midwest infected more than 6,500 people.
- In 2008, the biggest U.S. measles outbreak in a decade ran through 13 states, including Missouri and Illinois, sickening 140 children and hospitalizing 20.
- In 2009 another measles outbreak in the New York area infected as many as 1,500 people within a matter of months.
"The effect of the anti-vaccine movement is really starting to take hold in this country and we're seeing pertussis epidemics in some cases like we haven't seen in more than 50 years," said Dr. Paul Offit, chief of infectious diseases at Children's Hospital of Philadelphia. "There was an outbreak in California that at last count involved more than 6,400 people and killed 10 children."
Offit has served on the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices. He is author of five books, including his most recent, "Deadly choices: How the anti-vaccine movement threatens us all."
Offit said an unvaccinated person traveling abroad, contracting an illness and then spreading it upon return to the U.S often causes incidents like the California outbreak of pertussis, commonly known as whooping cough. In a heavily vaccinated society, there is little worry because an infected host has few places to spread the virus they carry.
The math changes however as immunity rates drop.
"We've had deaths from a form of bacterial meningitis that's been preventable for 20 years," Offit said. "Four deaths, one in Minnesota and three in Philadelphia, all within the past couple years. So I think we're past the tipping point."
Setting The Record Straight
Dangers associated with vaccines can be real. Offit said vaccines made in eggs for yellow fever, or in gelatin for chicken pox, can trigger allergic reactions from the few individuals sensitive to such substances. Oral polio vaccine, in 1 out of every 2.4 million doses, caused the very disease it was meant to eradicate. The polio vaccine was modified to include an inactive virus. John Salamone, a parent whose child was harmed by the live polio vaccine, played an important role in its modification.
"His story was compelling and it really put a face to what were the six to eight cases of polio caused by the vaccine every year," Offit said.
"That," Offit added with emphasis, "was a vaccine safety advocate."
However, Offit says, the fears driving modern anti-vaccine efforts are not based in science. In 1998, a study published in the medical journal the Lancet touched off a panic over a purported link between the mumps/measles/rubella vaccine (MMR) and the onset of autism in children. Other research was never able to replicate that study's results. The Lancet retracted the paper last year upon discovering problems with the study. Earlier this month investigators found evidence of falsified data in the original study.
Unfortunately, once an idea has taken hold, it can be resistant to contrary information, Offit said. Much like a virus, it often mutates. The autism rumor first concerned the vaccine itself and later became attached to a preservative called thimerosal, meant to prevent bacteria growth within the vaccine. Thimerosal isn't used in American vaccines anymore.
"Then the hypothesis shifted again to a more diffuse and less easily tested idea, that there were just too many vaccines too soon (in a child's life) that are causing autism," Offit said. "The idea was that it was somehow perturbing or weakening the immune system."
Dr. Edwin L. Anderson, a St. Louis University research professor, said he's heard that one from parents before.
"They seem concerned that the vaccine is going to harm their child and they don't always specifically state what harm they are concerned about," he said.
Anderson is familiar with claims about the immune system being dampened.
"That's certainly not true," he said. "The vaccines, if anything, stimulate immune function."
Ironically, vaccines may be victims of their own effectiveness. Parents who didn't grow up seeing the horrors of diseases like polio running unchecked don't necessarily know what immunization really prevents.
"I don't think they realize it, but they are taking advantage of everybody else," said Dr. Gregory Storch, director of pediatric infectious diseases at Washington University. "They're saying 'OK, you go and get the vaccine and take whatever risk there is' because there is some small degree of risk in anything. 'You take on that risk and you pay the cost of getting the vaccine. I'm just going to benefit from the fact that you and others are immune'."
Dr. Gregory Finn of Blue Fish Pediatrics in Des Peres felt similarly. His office has a policy of not taking children as regular patients if their parents don't agree to an immunization schedule.
"We'll have long discussions with them and try to address all their questions, but if they do choose not to vaccinate, we say, 'well, I think our philosophies are too different'."
But while Finn said some parents have questions, almost none refuses the immunizations. He estimates that only about once every five years does he see a parent who can't be convinced.
"With the number of babies we see that's pretty rare," he said.
Are the community benefits from vaccines fading? The answer is difficult to pin down with certainty. Massive epidemics aren't occurring, but Offit worries that periodic outbreaks indicate that herd immunity may be "fraying around the edges."
"Could it be worse?" he said. "Sure. And maybe it will be worse."
Measles, a highly communicable disease, is one example. Storch said outbreaks in the late 1980s and early 1990s, when immunization rates were likely above 90 percent, showed that the illness doesn't require much of an opening to gain a foothold.
"In some cases, it doesn't take that much of a decline in the percentage of people who are immune to allow diseases to get started again," he said. "The more contagious they are, generally the higher the level of immunity that's required to keep the population protected."
And some populations need to be protected. Offit said that as many as half a million Americans can't be vaccinated for one reason or another. Those going through chemotherapy or immunosuppressive therapy are examples. Infants, meanwhile, often take months of booster shots to be fully immune and must rely on herd immunity for protection. The 10 who died in the California pertussis outbreak illustrate that point.
"All of them were less than 3 months of age so they couldn't have been fully immunized," he said. "They depended on those around them to be vaccinated."
No Vaccine Is 100 Percent Effective
There's no doubt where Erin Karvas stands on the issue.
"It's pretty foolish not to get your child vaccinated," said the 22-year-old St. Louisan as she waits for her 6-month-old son, Zackary, to get his shots.
She's heard the rumors and even had a friend who was dubious about having her own child immunized. Karvas talked her into the vaccination, even showing her a news report on the topic.
"I've seen kids on TV have whooping cough," she said. "It's so awful. Kids die from whooping cough."
In the 1930s hundreds of thousands of Americans got pertussis, said Dr. Ken Haller, an associate professor of pediatrics with SSM Cardinal Glennon Children's Medical Center and St. Louis University. By the 1990s the number of cases was in the low thousands. Since skepticism about immunizations has emerged, pertussis is resurging.
"Now we're up in the range of about 20,000 to 25,000 per year," Haller said. "That's because significantly large numbers of people did not get vaccinated."
Eleven school districts in the St. Louis area have reported cases of pertussis.
He believes coverage of recent pertussis outbreaks have raised awareness. He does still sometimes hear questions about vaccines, but usually it's over immunizations for influenza. Though it's impossible to get the flu from a flu shot, because it contains no live virus, Haller estimates that about one of every five patients query him over its safety. He said people who get the shot and become ill may think the vaccine was the cause. Usually it's either because they had an unrelated cold or had already been exposed to the flu before the injection.
Another explanation is that the vaccine simply didn't work. No immunization is completely effective. The flu shot works about 85 percent of the time, Haller said.
The H1N1, or swine flu, shot prompted special concern.
"The big urban legend we heard there is that it hasn't been tested enough," he said. "Yet the H1N1 vaccine last year got as much testing as any other flu vaccine gets. The only reason it was put in a separate inoculation was that that year's flu vaccine had already been developed."
Haller said most patients accept the vaccination after he's explained the facts.
The other question he hears a lot pertains to Gardasil, the inoculant against human papillomavirus (HPV), a common STD linked to cervical cancer. Some objections are moral, with parents of teens believing they are encouraging sexual behavior in their children by getting them immunized.
Others have heard it has bad side effects.
"The safety profile of HPV vaccine has been very good," he said. "There hasn't been any evidence of anyone having a truly adverse effect because of the vaccine."
That safety profile is courtesy of VAERS, or Vaccine Adverse Event Reporting System, a protocol set up by the CDC to sift through data in search of potentially dangerous patterns among vaccine users. Haller said many in the general public aren't aware the reporting system exists.
"When there is a problem it does get reported and it does get taken care of," he said.
David Baugher is a freelance writer in St. Louis.