Asymmetrical Information - Megan McArdle

06.03.13

Why You Should Vaccinate Your Sons for HPV

Both boys and girls can get cancer from HPV. Protect them now, before it's too late.

In a wide-ranging interview, Michael Douglas says that his throat cancer was probably caused not by a misspent youth of drinking and smoking, but by HPV. Yes, HPV, the same virus that causes cervical cancer. The same virus that got Texas Gov. Rick Perry in trouble when he tried to make vaccination for it mandatory.

In general, I'm not in favor of expanding the power of the state over private decisions. But I make an exception for public-health issues—genuine public-health issues where you're stopping epidemics from spreading, not noninfectious pseudoepidemics like obesity and smoking. So I sided with Rick Perry: girls should be vaccinated for HPV. The chance to prevent more than 12,000 annual cancer diagnoses, and 4,000 deaths, is worth the very small risks of side effects.

But as Michael Douglas's case illustrates, Rick Perry did get one thing wrong: he left out boys. Thanks to the rise of oral sex, we now know that HPV doesn't just cause cervical cancer; it can also cause throat cancer. Ear, nose, and throat doctors are now seeing more and more cases of throat cancer in younger men, caused not by drinking and smoking, but by human papillomavirus.  

HPV-linked throat cancer is still rarer than cervical cancer, but it's also more dangerous, because there's no throat equivalent of a Pap smear. Cervical cancer has a very high survival, because most women now get regularly checked for it, so it's caught early. Throat cancer, on the other hand, tends to get caught when you have a lump large enough to be noticeable, or a bloody cough, or some other symptom that says "this has already gotten really bad." 

Obviously, not everyone agrees with me that HPV vaccination is a great idea, however. The arguments against HPV vaccination come in two varieties: the possible side effects and the concept of vaccinating young children against a sexually transmitted disease. Let's deal with them in order.  

No matter what you may have heard from anti-vaccine activists, the risk of serious side effects from vaccines is incredibly low, and even that low risk can be mitigated if you watch your child closely in the few hours after a vaccination and get them to the hospital at the first sign of an allergic reaction. According to the CDC, the risk of permanent side effects from a vaccination is about 1 in 1 million, or 4 per year.  The number of deaths is so low that a three-year study of all the deaths in the country could find only one death that was clearly vaccine-linked. Your child is at vastly greater risk from a swimming pool or the family minivan.

But why take even that small risk? Why vaccinate a prepubescent child against an STD?

Because now is when you have control of their bodies. You don't want to depend on a teenager or young adult to responsibly go and get the vaccine before they become sexually active. If you remember your own life during those years, you probably recall a number of incidents during which you did not do the prudent, responsible thing. If you were anything like me, you frequently acted as if you were invulnerable and immortal, because you didn't really believe, deep down, that anything permanently bad could actually happen to your body. Even if you weren't anything like me, surely you had friends and relatives who made those sorts of mistakes. Don't depend on your kids to make sure they're protected. Protect them now, so there's no possibility that they'll have sex before they're vaccinated.

But what if you're raising your children to wait until marriage? You should still vaccinate.  

No, don't get mad. I'm not saying this because I think that waiting until marriage is some sort of weird, crazy, impossible thing that only a retrograde Bible thumper would even contemplate. I firmly believe that it is reasonable to tell young adults to remain abstinent until marriage, not some sort of heroic expectation along the lines of demanding that they win the Nobel Prize in Physics. I respect your values, and I am in no way suggesting that you should compromise on them. Rather, I'm saying that vaccinating for HPV is perfectly consistent with raising your kids to wait until marriage.

Here's why: the lifetime risk of getting HPV is somewhere around 80 percent. Your child may wait until marriage, but you probably can't guarantee that they will marry someone who also waited. People slip up. Or they come to Christ later in life, after they've already made some mistakes. This is not a rare disease. It is a disease that your child will more likely than not be exposed to. And it's largely asymptomatic, so there's no good way for them to tell that they're being exposed.

There's also the small but real risk of rape. I don't think I need to say any more about this than that, other than that it would be a damn shame if on top of their terrible suffering, they also got cancer.

Here's another reason you should vaccinate, even if you're raising your children to be chaste until they're married: we now know that HPV can be transmitted orally—meaning that your child might be able to get HPV just from kissing someone who has an active infection. To be sure, the risk of oral-to-oral transmission seems to be pretty low. But it's not clear that it's zero. Given the incredibly low risk of side effects, why take the risk?  

And of course we should acknowledge that even great kids who were raised in strong families with good values do occasionally make mistakes. Which you know if you're a parent, because you've watched your kids slip up from time to time. I know all sorts of people who cheated on a test, or shoplifted a few times, or had a party in the house while Mom and Dad were away, depsite the fact that they are fundamentally very good human beings. They did these things not because they had bad parents or were bad people, but because most human beings sometimes give into temptation. You are not, every minute, the mother or father, the son or daughter, the co-worker, the person that you should be. Your plans should not assume that your children will manage the perfection you can't.

Planning for the worst is not the same as expecting it. Understanding that there's a risk they will do something wrong, and trying to shield them from the worst possible outcome, is not condoning that behavior—any more than making sure your kids buckle up is condoning reckless driving.  

I understand that parents worry that by vaccinating against HPV, they may be sending the message that premarital sex is OK or otherwise encouraging it. If you're really worried, then don't tell your kids they've been vaccinated; just silently protect them in case they don't live up to the values you raised them with. But I think this is taking the Peltzman effect a little too far. People don't run out and do something morally wrong just because it's now somewhat less costly. Besides, you don't send your kids out in a car that has a spear mounted on the steering wheel, pointed at their heart, merely because this might encourage safer driving. Nor should cancer be a deterrent against premarital sex.

I think it's perfectly possible to say "We expect you to wait until marriage because that's the right thing to do. But we can't control whom you will fall in love with and marry, so we're protecting you just in case—now, when your immune system is strongest."

To be sure, I do think this is one of the best arguments for universal vaccination: parents don't send any message by vaccination. They're just complying with the law. Yes, you can argue that society is sending a message—but have you turned on the television recently? Opened a magazine? Looked at a billboard? That message is already being sent very loudly. By comparison, HPV vaccination is like a tiny whisper in a full stadium.

The actual best argument is, of course, herd immunity. You vaccinate your kids not because you expect that they will have premarital sex, but because we can basically make this disease go away, if and only if we vaccinate everyone. Most people think that vaccination works by protecting you, and it does, but in fact, herd immunity is what makes vaccination nearly 100 percent effective. Over time, the power of vaccination can slowly attenuate (that's why you need a tetanus booster every decade). And of course, they don't work at all if your immune system is compromised—if you have an autoimmune disease or an organ transplant that requires suppressing your immune system, if you're very old or very young, or if your system has been weakened by another recent illness.

Herd immunity protects those people, because diseases constantly need fresh victims. If everyone is vaccinated, we deny this disease the reservoir it needs to keep going. That's how we got rid of smallpox, and despite setbacks, we're on track to eventually eradicate polio the same way. But for herd immunity to work, nearly everyone needs to be vaccinated; even 10 percent or 20 percent noncompliance is enough of a reservoir for diseases to keep going.

Twelve thousand cases of cancer, 4,000 deaths, every year. Not every one of those cases would be prevented, because the vaccines only cover the most common (and cancer-causing) strains. But a lot would be. Even if you don't think your kid is at risk, global vaccination will help us save a lot of lives, which is why I hope that everyone, including those who believe that premarital sex is morally wrong, will support it. Getting a basically harmless shot is a pretty small price to pay for ending cancer.

We probably won't get mandatory global vaccination any time soon, of course. In the meantime, I hope that everyone will voluntarily vaccinate their kids. Yes, even if you're pretty sure they won't need it.

Imagine if your kid was one of those cancer victims. Imagine your 38-year-old son coming to you with the news that he has stage IV throat cancer, requiring radiation and chemotherapy that may take his voice, or his life, and will definitely leave him unable to eat or drink for many months because of the searing pain. Imagine finding out that your 29-year-old daughter had had to have part of her cervix painfully cut out and now may never be able to carry a baby to term. Maybe your child made a bad mistake when they were 20, or maybe their spouse did, or maybe you'll never know who kissed the person that eventually gave your child cancer. No matter how it happened, I'm guessing that you'd feel pretty awful knowing that you probably could have prevented this by giving them a shot 20 years before.