When I was little, I was vaccinated for the things that were recommended at the time: polio, measles, German measles (rubella), diptheria, tetanus, whooping cough (pertussis). I had the mumps and chicken pox when I was little, and was re-vaccinated for measles before college (because the late 60′s vaccine wasn’t effective enough, I think). My kid’s list of vaccinations has been much longer, and includes a lot of diseases I didn’t recognize immediately (Hib, for instance). A lot of parents I know are skeptical of vaccinations – aren’t they potentially dangerous, and maybe better when kids get older and have stronger immune systems, and aren’t they a bit of a scam from drug companies?

This year there are going to be two flu vaccines: one for the expected type of seasonal flu, and one for the pandemic H1N1 “swine” flu. The swine flu vaccine, in particular, is especially recommended for pregnant women, children, young adults, and people who work with children. The parenting blog for my local paper, Kid Row, recently raised the Vaccine Question: yes, the CDC is recommending that kids be vaccinated, but should we listen to them?

And another vaccination-related issue has come up locally. We’ve been having outbreaks of pertussis (whooping cough). Major outbreaks. Big enough that Center for Disease Control investigators have come to town to try to figure out what’s happening, and especially why there are cases with different symptoms from normal.

The only commenter on the Kid Row blog suggested that everyone “think twice” about vaccines. Ok. I’m a scientist (though one whose methods are very different from those of biomedical science, and one with a lousy biology education that ended in my sophomore year of high school with a teacher who told us that evolution was wrong and that girls couldn’t do science). And I’m a parent. And I can read. So, this is me, thinking.

First question: what’s being prevented? I grew up in a time and place where diseases such as diptheria and polio were unheard of, except when the time came to vaccinate. And in the case of other diseases, I only knew the common name (“chicken pox,” “meningitis”), not the name that goes with the vaccine (“varicella,” “Hib”). So it’s difficult to get a feel for the risks associated with the diseases that have become rare as a result of vaccination. This post from Making Light does a great job of combining the medical information with stories from the days when the diseases were common. The descriptions alternate with the wording from headstones from a graveyard in Vermont – gravestones for infants, toddlers, pre-schoolers. (Back when I was doing fieldwork in Vermont, I ran across a similar graveyard from the early 1800′s – so many headstones for young children. Some of the saddest were stones where several children, all dead in the same year, were buried.)

The short version: some of those diseases (such as diptheria and whooping cough) were major childhood killers. Others (such as chicken pox and the mumps) are worse for adults than for children (luckily for me, since I had both when I was little). By making a large proportion of the population immune, vaccines prevent these diseases from spreading the way they once did. And that protects even those who can’t be immunized (because of allergies or other risks of complications).

Second question: what are the risks of the vaccination? That’s the question that my acquaintances want answered. After all, this isn’t 1830, and we don’t know anyone who has had these diseases (except chicken pox, and we all survived). Are the benefits worth the risks these days?

There are a bunch of answers to this. Some are on the information sheets that everyone is given before vaccination. They list the reasons not to get a particular vaccine – which factors make people more likely to have an adverse reaction. So I read those carefully, and ask the doctor questions, and try to figure out if the kid is in one of those risk groups. (He hasn’t been.)

And then my acquaintances shake their heads, and pass me an issue of Mothering magazine, and ask me if I’ve heard about vaccines and autism.

Yes, I have. I read Mothering for a year. I’ve also read Chris Mooney’s recent piece in Discover about this history of the vaccine/autism claims. (And I blog on the same site with biomedical bloggers such as Orac, Tara, Revere, and PalMD, all of whom discuss vaccinations.) And between the lack of a decrease in autism when the US stopped using thimerosal in vaccines and the amount of other research evidence that has piled up, the evidence for autism being caused by vaccines seems pretty weak. (And I mean that in the same way that I mean “the evidence that earthquakes can be predicted from lists of runaway dogs seems pretty weak.”) I may use different methods from biomedical scientists, and I might not fully trust drug companies, and I might be jealous of medicine’s prestige and appeal to students (Nobel prizes… you’d think they were going to cure cancer or something). But when a lot of scientists come to the same conclusion based on different sorts of studies, I’m willing to trust them. Yes, even though I know scientists are human, and even when it involves my kid.

Third question: fine, take the risks for your kid. But shouldn’t everyone choose for themselves? Well… I’m going to defer to the local ethicist on this one. Janet Stemwedel took on the ethical issues involved in taking advantage of herd immunity back in June. And it’s a powerful argument: people who live in a society that vaccinates are getting all the advantages of herd immunity without taking on the risks. And if there are enough people who refuse the vaccinations, the herd can lose its immunity. Polio could come back. Whooping cough could become common, like it has in some communities. (Is vaccine refusal the reason why whooping cough has been making the rounds in Durango during the past few years?) And then the people who can’t be vaccinated (because they belong to a group that the CDC says has a higher risk: age, allergies, etc) have a much greater risk of getting infected.

Now, the flu isn’t polio. I’ve survived it without complications, more than once, and so have most people I know. But its complications do kill people. And the new H1N1 “swine” flu is likely to spread fast. And the populations at the greatest risk seem to be pregnant women, kids, and young adults.

My kid is in an elementary school. There are teachers at the school are pregnant, or who have young babies. And I teach young adults – and there are pregnant faculty members at the college, too. Maybe the vaccine will come too late – odds are that swine flu will start to spread rapidly through the community as soon as the students get back to campus on Monday. But if we haven’t all come down with it before October, my kid and I will get vaccinated. (And I’m going to get re-vaccinated for whooping cough, too.) Because it’s not just about the two of us. It’s about the herd.

And I like living in a world where graveyards aren’t full of toddlers’ headstones.