The 'herd' doesn't protect unvaccinated children

A growing number of parents are declining to have their children immunized for such diseases as polio, diphtheria, measles, mumps, rubella and pertussis. The result is that more outbreaks of these illnesses are emerging and -- surprise -- the children of parents who refuse immunizations are at much greater risk for infection.

A study published today in the journal Pediatrics found that children whose parents declined to have them vaccinated had 23 times the risk of being infected with pertussis compared with vaccinated children.

Parents used to fear these childhood illnesses but today, the authors of the study note, some parents fear the vaccines more than the illnesses. They believe the vaccines overload a child's immune system and may cause dangerous side effects or they simply don't think their child is at risk for the diseases.

The study, by researchers at Kaiser Permanente Colorado and Johns Hopkins Bloomberg School of Public Health, analyzed data from children in the Kaiser Permanente health plan in Colorado from 1996 to 2007. Each case of pertussis was matched with four randomly selected control cases. The study found that in the entire Kaiser Permanente population, 11% of all pertussis cases were attributed to parents' refusal to have their children vaccinated.

Even though most children are vaccinated, there isn't enough protection in the population -- called the herd immunity effect -- to protect unvaccinated children from contracting the illness, the authors say. "This result dispels one of the commonly held beliefs among vaccine-refusing parents that their children are not at risk for vaccine-preventable diseases," they wrote.

The authors note that parents who are inclined to skip recommended vaccinations should receive information about their children's risk of getting the disease. The American Academy of Pediatrics has a position paper on the topic entitled, "Responding to Parental Refusals of Immunization of Children."

-- Shari Roan

Photo: Tim Boyle / Getty Images

Comments

[Medicine Shoppe]

According to Medicine Shoppe experts, more vaccines are actually a good thing! Every new vaccine protects more kids from getting sick, expensive hospital stays and perhaps death or permanent injury. More kids are prevented from getting devastating diseases than ever before, thanks to vaccines. And even though the number of shots has gone up, the actual load on the immune system has gone down. That’s because today’s vaccines are “smarter” and better engineered than the shots from a few decades ago.

[Duncan]

You have the following statement in the article:

..."11% of all pertussis cases were attributed to parents' refusal to have their children vaccinated.".......

So what are the other 89% attributed to?

[Trish Parnell]

Most parents want to take care of their children, but finding the best way to do that can be difficult.

When my child had hepatitis B, I didn't go to my hair stylist for advice, I went to a hepatologist. A scientist. I wanted to talk to many scientists about what the best care would be for my child and then make a decision based on the most up-to-date science.

If you're not sure about vaccinating your child, talk to a few scientists and get the facts. Science isn't perfect, but it's the safest route to take.

[shawmutt]

Good article. I only have to add the fact that pertussis shots are not given to a baby until two months of age, and that is the age that pertussis has a good chance of being fatal. The breakdown of herd immunity not only affects those that can make the choice, but also those who do not have a choice yet. Vaccinate your kids!

[dave]

The article that appeared in the Los Angeles Times 3/29/09 has
generated a lot of discussion, and I was asked to respond.

Unvaccinated children do not pose a threat to vaccinated children or
their families.

We all have a responsibility to keep each other's children safe.
Choosing to not vaccinate or choosing an alternative vaccine schedule
could be considered a rift in that contract. Medically, scientifically
and statistically speaking, it is not. Honest people might disagree.

I have been a pediatrician for thirty years and have watched children
receive all scheduled vaccines, some of the vaccines or receive no
vaccines at all. I have seen every one of the illnesses against which
we vaccinate. Since the early 1980s, I believe I've only seen once
case of bacterial meningitis in a child and one other case in a
teenager. The rarity of this terrible disease means that it makes the
news whenever a case occurs but denying that childhood meningitis
still exists is dishonest. Equally dishonest is implying that it is a
large threat to any of our children. I see kids with pertussis every
year. I see children misdiagnosed with whooping cough far more often.
Two years ago, the New York Times took note of this phenomenon.

2009 marks the thirty year anniversary of the last case of "wild
polio" in the United States. Subsequent cases were caused by the oral
polio vaccine which is no longer used in this country.

http://www.polioeradication.org/casecount.asp (WHO/CDC supported site)

Rubella is no longer an "American" disease.

http://www.cdc.gov/od/oc/media/pressrel/r050321.htm (CDC Press Conference)

I recently read an article, written in 2009 which chastised
non-vaccinating parents because there had been 131 cases of measles in
the U.S. in the first half of 2008 alone. And how many cases were
there in the whole year? 134. The usual number? 62. Disingenuous
reporting. An extra 72 cases of measles among 300,000,000 Americans
made the papers every day or two for months and the LA Times writers
dredge up the child who caught measles on a Swiss vacation one more
time.

Yes, as mentioned, measles and other viruses can cause encephalitis.
It's very, very rare. Implying otherwise could scare parents.

And, no, the law does not allow us to know which children have not
received vaccines any more than it allows other invasions of privacy.

I have received hundreds of emails from people all over the country
and the world reaching out to me and asking me to listen to them about
vaccine issues and injuries because it seems that no one else will. I
have permission from a mother to forward email she sent to me-with a
picture-of her four month old daughter who received four vaccines and
died shortly thereafter. I have dozens and dozens of similar emails
and dozens of face-to-face encounters in my office with parents coming
to me after what they considered to be vaccine damage to their
children. I will not forward that email. It creates a different kind
of fear that also doesn't serve the dialogue well.

I think that these possibly injured children and families represent
one end of the bell shaped curve and that scary stories about
meningitis in Minnesota (the first there in 18 years) represent the
other end. (I do feel that the former end of the curve is far fuller
than the latter but no proof exists. None.)

The LA Times stories were "fear-based" just as my forwarding these
emails would have been.

The University of Michigan Law Review recently invited me to write a
journal article about vaccines and tort law.

I sum up my law review presentation to parents every winter by telling
them that the only way to avoid childhood illnesses is "reverse
isolation" of your illness-free child. If you go to a two-year-old's
birthday party during the winter months . . . You will probably get
sick.

Peripherally, let's all remember that it took fifty years or more,
thousands of court cases and a lot of money to finally prove the
connection between cigarettes and cancer. The three court cases
showing no connection between vaccines and autism should make no
headlines and should be an impetus to honest investigative journalism.

We have increased the number of vaccines and the combinations of
vaccines given to babies and children. Adequate testing has not been
done. I have seen a huge rise in the number of children with autism.
Neither I nor any other doctors are hundreds of percent better at
diagnosing this spectrum of developmental delay than ten or twenty
years ago. The dramatic rise in the number of cases of autism spectrum
disorders is attributable to something other than "reclassification"
or better diagnosis.

While waiting for scientific proof, we have to tolerate families'
completely legal and scientific desire to have or not have their
children given vaccines according to the current schedule.

JNG MD, FAAP