Danger from the unvaccinated?

My daughter is about to start school and I’m wondering about the consequences–for her–of the California mommies who think vaccination is evil. In practical terms, my kid is okay, right? Outbreaks of German measles or what have you will be confined to the unvaccinateds, as they should be…correct?

Mostly. But there’s this thing called “herd immunity” which means that the nutters are endangering your kids, as well as their own.

“Lack of complete vaccine coverage increases the risk of disease for the entire population, including those who have been vaccinated, because it reduces herd immunity. For example, measles vaccine targets children between the ages of 9 and 12 months, and the short window between the disappearance of maternal antibody (before which the vaccine often fails to seroconvert) and natural infection means that vaccinated children frequently are still vulnerable. Herd immunity lessens this vulnerability, if all the children are vaccinated. Increasing herd immunity during an outbreak or threatened outbreak is perhaps the most widely accepted justification for mass vaccination. Mass vaccination also helps to increase coverage rapidly, thus obtaining herd immunity, when a new vaccine is introduced.”

My understanding is that while many vaccines are very effective (99+%), a (very small) risk remains for a vaccinated person to become infected if they’re that unlucky 1 in 100 or 1000 or whatever.

I’ve had three rubella shots and still test negative for rubella antibodies. Either I’m one of those people that the vaccine just won’t work for, and I’ve lucked out with the herd immunity, or the vaccine(s) worked and I somehow don’t show it. The former seems more likely.

Oh, and my doctor decided that I was old enough to need a whooping cough booster. So at least some of them will wear out.

Vaccine efficacy from close exposure is often at about the 90% mark (see this pertussis study, for example), meaning that if vaccinated with a complete and up to date series your child has one tenth the chance of catching the disease than does an unvaccinated individual given the same exposure.

Still, do the math. Assume someone exposes 1000 kids and 5% of them are unvaccinated compared to 95% who are. Assume unvaccinated has a 10% of catching the disease each close exposure, so the vaccinate have a 1% chance each. First round, 5 unvaccinated kids get sick (10% of 50) and 10 vaccinated kids do. Yup, more vaccinated kids get sick than do unvaccinated ones. But it gets worse - those new cases also expose other kids. Sure it may end up that almost all the unvaccinated kids get sick but the vast majority of cases will still be among the vaccinated because of the vaccine refusers exposing so many of them. Real world numbers:

Your kid has a much decreased chance of catching it than an unvaccinated child does, and in particular is well protected from the most serious consequences, but those kids with the idiot parents are still putting your child at needless risk.

Grrrr. Stupid rich hippies. Thank you for the info.

Superbowl Measles Outbreak

Reading this I wondered if it was possible that there is something about you that means the rubella virus cannot grow and so the inoculation with (let me imagine) a weakened strain has no effect. Nor would the ordinary disease.

Our family doctor considers refusal to vaccinate a form of child abuse. And my physician DIL has a real problem accepting such children as patients–although she will, reluctantly.

Do schools in Cali (or anywhere) have to publish the rate of vaccination among their pupils? That seems like it would be a good way to discourage this (as it would make it very much in the schools interest to make sure their vaccination rate stayed high, but encouraging parents to vaccinate their kids).

Here’s a map for southern California Map: High-risk schools in Southern California showing vaccination rates at schools

Thank you for the map. I’m relieved to know that my daughter’s school is not one with a high(er) percentage of unvaccinated kids. I asked this morning, by the by, and was told it is less than 1%–but who knows.

Is 7.5% a number that has relevance to doctors? Or a cutoff chose by the LA Times?

That’s an interesting map. Every school I clicked on was very small–less than 50 kindergartners each, and often no more than 10.

To me, it seems like there’s a kind of clustering problem going on here. If you have a 1% non-vaccination rate, and look at a bunch of samples with 30 samples each, you would expect that many of them would have fluctuations of tens of percent. About 0.3% of 30-student kindergartens will have at least a 10% non-vaccination rate (again, assuming the overall rate is 1%). 0.4% of 10-student schools will be at least 20%. The LA area must have many thousands of kindergartens, so you’d expect lots of these examples.

I’d be far more worried if there were a 1000-student school with a 5% rate…

Why are people allowed to refuse to vaccinate, anyway? At the public middle school I attended, my mom had to fight tooth and nail to get my sister in without an MMR (she wasn’t able to be vaccinated for health reasons). I took away the impression that it wasn’t possible to choose not to vaccinate, and that people who did choose not to vaccinate (for any reason other than an excuse from a medical doctor) meant the school wouldn’t allow the parent to enroll their kid there.

There are small numbers of people who legitimately cannot be vaccinated due to medical reasons - allergic reactions to previous vaccines, for example. There are also small numbers of people who are legitimate members of religious paths that reject medical science.

In the example of the first, I believe that those children should be allowed to attend public school without vaccines. In the second, I’m torn but leaning toward the side of “attend your own private religious schools.”

As the mother of a newborn, non-vaccinators (sp? That doesn’t look right.) piss me right off. Littlest Miss is too young for vaccines, and people are too touchy - especially well-meaning old ladies and little children - so I’m following doctor’s orders to “be a hermit for the next month,” be cautious about the big kids’ when they come home from school (wash hands, change shirts before they play with the baby,) et cetera. I also had to bully my mom into getting a DTP booster, since pertussis in adults is pretty much indistinguishable from the non- productive cough she gets every spring. (Plus Mom visits Grandmother at the nursing home daily. She can easily catch or transmit whooping cough there.) Even my mother, who is normally a somewhat reasonable and perfectly intelligent adult, had to be coerced - “either get the damned shot or wait to see the baby after she has hers.” I’m not a fan of a nanny state, but I would be in complete favor of a law requiring vaccines for all but the medically exempt. If we can require seat belts and bike helmets for the common weal, why not innoculations? Vaccines save lives. Period. (Yes, I know there are extremely rare adverse reactions. My child will take that chance, because I’d rather take the modest risk of a bad reaction versus the real risk of serious risks from measles, mumps, rubella, whooping cough, tetanus, diptheria, chicken pox, etc.)

I am of the opinion that they need a Doctors note or stay out.

Are Christian Scientists still allowed to refuse their children lifesaving medical treatments?

In California there is some sort of religious or moral exemption, and of course there’s no test associated with it, as there shouldn’t be–if you say it’s against your beliefs, fine. The problem isn’t Christian Scientists, it’s the Jenny McCarthy brigade.

Here’s the link where I found the map http://scienceblogs.com/insolence/2011/06/a_vaccination_tool_every_parent_could_use.php - it implies that 10% is a relevant cutoff, but doesn’t say so explicitly

No, your beliefs should not be able to endanger other peoples kids. No religous exemptions should be allowed.