“Compliant” means a girl has started her course of three vaccine injections and is not overdue for later shots.

Today was not-a-column day, and I wrote about the District’s four-year-old law requiring sixth-grade girls to get vaccinated against the human papillomavirus, or HPV, which causes most cervical cancers. The HPV vaccine was the talk of the Republican presidential race earlier this month, thanks to Texas Gov. Rick Perry’s short-lived 2007 executive order mandating it for his state’s sixth-grade girls.

The District happens to be one of two places in the country where the HPV vaccine is required by law. And while Virginia also has a vaccination requirement, there is no formal reporting requirement and parents can simply skip the vaccine. In D.C., a parent-signed waiver needs to be submitted to their daughter’s school.

But the law alone hasn’t guaranteed that District schoolgirls are protected from cervical cancer. According to the D.C. Health Department data above, compliance with the law improved last year, but substantial compliance remains a distant goal.

Among the first cohort of 6th graders eligible for the vaccine, 18.2 percent are protected — meaning they are set to complete the series of three shots. Parents of 44 percent of those girls waived out of the vaccination. The remainder did not start the course or are overdue for their second or third shots. For the more recent cohort, which were in 6th grade last year, 23.5 percent are in compliance. A slightly smaller percentage, 42.1 percent, have sought waivers.

For answers as to why, read the not-a-column.

It’s instructive to compare the District’s rates of HPV vaccination with national rates. The Centers for Disease Control recently released 2010 coverage estimates for the 50 states and some metropolitan areas. The District does fairly well in the ranking, compiled from statistical samplings of medical records, but it’s not among the very best.

In terms of percentage of adolescent girls who have gotten at least one dose of vaccine, the District (57.5 percent) is estimated to be behind Rhode Island (73 percent), Washington (69.3) and five other states, as well as the cities of New York (62.7) and Philadelphia (60.2). In terms of percentage who have gotten three or more doses, the District, at 33.8 percent, is more middling, ranking behind 21 states and those two major cities. In both cases, however, D.C. remains above national averages.

Of the cohort examined by the CDC — those aged from 13 to 17 — only the very youngest will have been in sixth-grade classes covered by the new mandate. In other words, it’s too early to tell if the law will significantly improve vaccination coverage among District girls. But with the Health Department data showing that fewer than a quarter of girls are getting protected, the coverage rate might not improve much.

One other issue of note: The statistics show dramatically lower compliance rates for parochial schools — that is, schools operated by the Catholic Archdiocese of Washington.

While a vaccine given to young girls to prevent against a sexually transmitted infection presents some complicated moral questions, Brie Hall, a spokeswoman for the Archdiocese, said there has been no willful lack of compliance by the church. A letter (below) provided to parents shares religious guidance on the issue; for instance, the National Catholic Bioethics Center, Hall writes, “considers the HPV vaccination to be a morally acceptable method of protecting against disease, but that the parents of a child have the authority to make the decision regarding the HPV vaccine.”

Hall said the Archdiocese has “not received any central communication” from health officials about vaccine compliance.