[Eugene Volokh, February 5, 2007 at 5:36pm] Trackbacks
HPV Immunization in Texas:

Last Friday, Texas Governor Rick Perry issued an executive order requiring that "[t]he Health and Human Services Executive Commissioner shall adopt rules that mandate the age appropriate vaccination of all female children for HPV prior to admission to the sixth grade," though allowing parents to refuse on conscientious grounds. (The relevant state statute, Health & Safety Code ยง 161.004(d), provides that "A child is exempt from an immunization required by this section if ... a parent, managing conservator, or guardian states that the immunization is being declined for reasons of conscience, including a religious belief.")

The governor's action has led to a good deal of objection, from both social conservative and libertarian circles. I thought I'd pass along a few tentative thoughts of my own. Because the aggregate of the thoughts is long, I'll break it up into a few posts; in this one I'll just set out the key facts:

HPV (Human Papillomavirus) apparently causes about 70% of cervical cancers; there are about 10,000 new cases of cervical cancer in the U.S. per year, and 3700 deaths, which means that HPV kills about 2500 American women each year. HPV is sexually transmitted; the vaccine, the CDC reports, has been tested on 9-to-26-year-olds and appears to be nearly 100% effective if administered before a woman acquires HPV. It has not, however, been tested on women over 26, and thus is not recommended for them.

I can't speak to how safe the vaccine is, though I have no reason to doubt the CDC's view that it is safe. If it is indeed too risky, that would of course be a plausible objection to it, but I'll set that aside for now. Rather, in coming posts, I'll discuss whether the vaccine is likely cost-effective; whether it might be counterproductive because it will lead to more risky sex and thus more diseases that stem from it; whether HPV is different enough from other diseases that government-mandated or even government-strongly-suggested HPV vaccination is improper; and how we might think about truly mandatory vaccination (which this doesn't seem to be) more generally.

Related Posts (on one page):

  1. Transmission of Genital HPV Through the Hands:
  2. "100% Preventable by Behavioral Change":
  3. Libertarianism and Communicable Disease:
  4. HPV Immunization and Risky Personal Choices:
  5. Perverse Effects of HPV Immunizations?
  6. Cost-Effectiveness of HPV Immunizations:
  7. HPV Immunization in Texas:
Dr. T (mail) (www):
The law is illogical from an epidemiological standpoint. Vaccination policies are most effective when a high proportion (>70%) of the susceptible population can be made immune to a communicable disease. The "herd immunity" effect lowers the risk of disease transmission for everyone (including those who did not get vaccinated or who did not respond to the vaccine).

By exempting boys from vaccination, the proposed law nearly eliminates the benefits of herd immunity. The girls incur the economic costs and medical risks of the vaccine but don't get maximal benefit due to the exemption of boys. Note that the vaccine is useful for men: HPV is a cause of squamous cell carcinoma of the penis.

My personal belief is that the vaccine should not be mandatory. The cost/benefit ratio is not nearly as good as Eugene Volokh described. I believe that only highly communicable (airborne or droplet spread) diseases should have mandatory vaccinations. HPV and hepatitis B vaccines should be voluntary.
2.5.2007 6:59pm
BobNSF (mail):
The vaccine is almost 100% effective against the four strains of HPV that it targets and that cause most (70%) cervical cancer cases. The benefit of herd immunity would be negligible for any individual girl, or her parents, weighing her options, no?

100% is pretty maximal.

Now, you do make a good argument for making the vaccine universal and mandatory, once studies on boys and men have been completed.
2.5.2007 7:23pm
Eugene Volokh (www):
I certainly have nothing in principle against making it mandatory for men -- but it would indeed require studies on an extra population, and of course it would be quite expensive. My tentative thinking was indeed that the herd effect is likely considerably less for immunizations such as this than for immunizations where everyone is covered; but I wonder how much less. Can anyone point me to a good analysis of the herd effect question for both the one-sex-only STD immunizations and for the both-sexes non-STD immunizations?
2.5.2007 8:00pm
guest1:
You said: "...the vaccine, the CDC reports, has been tested on 9-to-26-year-olds and appears to be nearly 100% effective if administered before a woman acquires HPV. It has not, however, been tested on women over 26, and thus is not recommended for them."

I haven't read the other posts yet, but I was wondering if this means that it appears to be nearly 100% effective if administered before a woman AGE 9-26 acquires HPV, or if they tested the "effectiveness" after age 26?

In other words, does the "not tested on women over 26" refer to the vaccine itself, or to the effects of the vaccine (or both)?

Point: If it only protects women from ages 9-26 but then the protection is lost, the protection is being lost when women are more sexually active (assuming, of course, there are more 27-year-olds then 9-year-olds having sex)
2.6.2007 12:04am