WEDNESDAY, Jan. 26, 2011 (HealthDay News) -- As long as vaccinations against disease have been around, there have been die-hard opponents convinced that these shots do more harm than good.
This type of "vaccine phobia" has perhaps never been expressed more vehemently than with the standard measles-mumps-rubella (MMR) childhood vaccine, which many insist is tied to autism.
Even after the retraction last year by The Lancet of the controversial study that first proposed such a link, and subsequent charges of fraud against its lead author, 18 percent of Americans surveyed in a recent Harris Interactive/HealthDay poll said they believed the MMR shot could cause autism.
Why are vaccines such lightning rods for suspicion and fear, despite scientific evidence that immunization campaigns have helped millions of people around the world live longer, healthier lives? One thing is for sure: the trend is not a new one.
According to a recent article in the New England Journal of Medicine, fear of vaccinations has been around since Edward Jenner administered his first smallpox shot in 1796. Skepticism waned during the middle of the 20th century, however, as the first large-scale immunization campaigns beat back longtime killers such as diptheria, tetanus, polio and measles.
And yet early in the 21st century, fear of vaccines has reared up once more. A study published in the March 2010 issue of Pediatrics found that although 90 percent of surveyed parents still thought vaccines offered good protection for their kids, almost 12 percent had refused at least one vaccine for their child.
These fears come at a real cost to public health, experts say: Declines in vaccination rates have been tied to recent U.S. outbreaks of measles and whooping cough, potentially fatal diseases the shots were meant to prevent.
Doctors have noted the trend, even among adult patients.
"I have been increasingly frustrated with efforts to vaccinate people in my clinic and how my persuasion efforts, which are formidable, are not working," said Dr. Len Horovitz, a pulmonary specialist with Lenox Hill Hospital in New York City.
"There's a mythology surrounding vaccinations," Horovitz said. It's not always logical, since some patients refuse "to put anything foreign [like a vaccine] in their body," even as they puff away on cigarettes, he added.
And vaccines seem especially singled out for distrust -- few people suspect other common therapies, such as cough syrups or antibiotics, of causing autism or other illnesses in kids. So why the lingering suspicion, despite so much solid science suggesting vaccines are both safe and lifesaving?
According to experts, one reason may be that immunization campaigns have become victims of their own successes.
"We're not seeing these [infectious] diseases any more," said Dr. Paul Offit, chief of infectious diseases and director of the Vaccine Education Center at Children's Hospital of Philadelphia. "For my parents and me, vaccines were an easy sell. I had measles, mumps, chickenpox. Fortunately, I didn't have polio, but I could have."
In generations past, the overwhelming benefits of vaccination were easy to spot as the numbers of children killed or disabled by infectious disease trickled away.
"We actually had an incident during the 1950s where the vaccine [in rare cases] may have caused polio," noted Dr. Max Wiznitzer, a child neurologist with Rainbow Babies & Children's Hospital, University Hospitals Case Medical Center in Cleveland. "Do you think people cared? They were so scared of polio that they kept lining up [for the shot]."
"In today's day and age that would never fly," he continued. "We're not seeing the natural infections any more, therefore we have a skewed view of the benefits and risks."
The fear seems also to have been fueled by an ever expanding and complicated vaccine schedule for younger children, with the U.S. Centers for Disease Control and Prevention now recommending 11 vaccines in multiple doses during the first six years of life.
All of that can play into parents' natural protective instincts for their children, Wiznitzer said. "Families always worry about their children's health, so if a claim comes up that vaccines could impact on their child's health, they worry."
In many parents' minds, more vaccinations must imply a higher potential for something untoward happening, and thus the wider benefits of immunization become overshadowed by that concern.
Also lying at the heart of things may be the simple fact that people are afraid of needles penetrating their bodies, or their children's bodies.
Unlike pills, for example, "shots are considered invasive. It's an aggressive act," explained Offit, who has just written a book, Deadly Choices: How the Anti-Vaccine Movement Threatens Us All. "A child is taken against their will, pinned down on a table or held by their mother. It can hurt and children can get as many as 26 inoculations in the first six years of life. People don't understand what's in the vial. [To them] it's just some kind of biological agent."
Barbara Loe Fisher is co-founder and president of the National Vaccine Information Center, which supports more research into the safety of vaccinations. In an interview for the Harris Interactive/HealthDay poll story, she said autism is just one concern linked to vaccines.
"Parents have legitimate questions about vaccine risks and want better vaccine science to define those risks for their own child," Fisher said. "This concern long predated the debate about vaccines and autism."
There's information on how vaccines work at the U.S. Centers for Disease Control and Prevention.