Certain types of human papilloma virus (HPV) are linked to cervical cancer, so when two vaccines for adolescents were developed to counter it — first Gardasil in 2006 and then Cervarix three years later — that was trumpeted as excellent medical news. And now studies show Hawaii ranks 14th among states getting the target population of adolescent girls vaccinated for HPV, with 40 percent immunized.

While that’s well above the national average, Hawaii can do better at making sure parents are equipped with the facts, which weigh heavily in favor of the vaccination. On the whole, adolescents tends to fall off the medical radar screen anyway, especially on immunizations. Many teens miss important booster shots, said Ron Balajadia, immunization branch chief with the state Department of health.

He added that Hawaii is on a normal trajectory toward adoption of the HPV vaccines, which people are generally slow to accept, especially where children are concerned. Many feel reticent about subjecting their child’s body to yet another injection.

And in this case, ordinary caution is compounded by a sensitive issue: a parent’s fears about their teenager becoming sexually active at an early age, since HPV is spread through sexual contact. They worry that giving their young daughters a shot aimed at immunizing them from a cancer-causing virus communicates that sex is now an acceptable activity.

That’s an understandable reaction. And in light of all the publicity surrounding Texas Gov. Rick Perry’s effort to mandate the vaccine through executive order, Hawaii can take satisfaction that here, the decision to vaccinate was rightly left up to the parents.

But in the context of an emotional issue, it’s easy for some basic truths to be forgotten. First is that a vaccination is not a free pass to risky behavior; it’s a way to give people protection from disease before they’re likely to need it. If they were to wait to protect themselves from sexually transmitted diseases until they’re about to be romantically swept off their feet, let’s face it: They won’t stop everything to get immunized.

Parents who are averse to immunizations can certainly educate their children about alternative protections, including abstinence and condom use.

Those who are simply concerned about possible side effects can draw on information that’s available from the Centers for Disease Control. For example, the centers lay out the potential side effects (cdc.gov/vaccines/vac-gen/side-effects.htm), as well as a recommended vaccination schedule (cdc.gov/vaccines/ recs/schedules/default.htm).

Balajadia said researchers are continuing to follow the earliest users of Gardasil and Cervarix to confirm what’s now the general conclusion, that these vaccines are safe. In the meantime, parents need to stay informed, with the help of public health agencies. And they must teach their teens that no single protection can ward off the range of diseases out there.

Ultimately, immunization decisions come down to an assessment of the risks, but making a sound decision requires arming oneself with the facts.