Vaccines are pretty nifty: Injecting a few tiny particles stimulates your immune system to build antibodies, which can bind to and help destroy harmful pathogens. A well-oiled immune system can neutralize these invaders before they have a chance to make you sick! In the war against infectious disease, we should be boosting our immune systems at every opportunity, and vaccines are one of the best weapons in our arsenal.

You’ve probably heard of HPV, or human papillomavirus, which causes genital warts and certain cancers. HPV has the dubious honor of being the most common sexually transmitted pathogen — some call it “the common cold of STDs.” According to the Centers for Disease Control and Prevention, “HPV is so common that nearly all sexually-active men and women get it at some point in their lives. This is true even for people who only have sex with one person in their lifetime.”

You might not know how easy it is to contract HPV — vaccination allows you to take charge of your health.

There are many strains of HPV. “Low-risk” strains can cause genital warts, which aren’t usually harmful but might be upsetting. “High-risk” strains can cause cancers of the cervix, anus, vagina, vulva, penis, mouth, and throat. The good news is that a vaccine called Gardasil protects against HPV-6 and HPV-11, which cause 90 percent of genital warts, and HPV-16 and HPV-18, which cause 70 percent of cervical cancers and 90 percent of anal cancers.

With protection available against a common virus that can cause upsetting warts or fatal cancer, you’d think that everyone would be lining up for Gardasil shots — but, unfortunately, vaccination rates are very low in the United States. Many of us opt out of vaccination for ourselves or our children because we don’t realize how easily HPV is acquired, or we minimize its potential to harm.

HPV is easier to contract than you might think, so if you think the risk is too small to outweigh other justifications against immunization, read on — you might not be aware of just how easy it is to acquire this wily virus. Vaccination is an empowering option for those of us who want to do all we can to take our health into our own hands. And, by being immunized, we can play a role in driving cancer-causing viruses into extinction, which would be feasible with sufficiently improved vaccination rates.

“I don’t have to worry about HPV. I always use condoms.”

Using latex condoms and other barriers, like dental dams, is an important part of protecting your sexual health, especially when you and your partner don’t know each other’s STD status. And condoms offer some protection against HPV — but, since HPV is spread by skin-to-skin contact, condoms are limited by the amount of skin they cover.

While using condoms consistently and correctly can reduce the spread of HPV, the level of protection offered isn’t as high as you might think. One study found that over an eight-month period, females whose male partners used condoms each and every time were 70 percent less likely to acquire HPV than were females whose partners used condoms only 5 percent of the time. Of course, 70 percent isn’t 100 percent, and even people who use condoms consistently can still transmit and acquire HPV.

Yes, condoms are an important tool for reducing HPV transmission, but they aren’t the only one. Vaccination offers much better protection against HPV than do condoms — although you should still use condoms to protect against other STDs and unwanted pregnancies.

“My partners and I always get tested for STDs. If one of us had HPV, we’d know about it beforehand.”

STD testing, especially before initiating sexual activity, is an important part of maintaining your sexual health. And, because so many curable STDs often lack symptoms but can cause damage if not treated, regular screening is to be encouraged.

Unfortunately, there are more than 30 STDs out there, and when you walk into a health center and say, “Test me for everything, Doc!,” you’re not actually going to be tested for everything. For example, although trichomoniasis is quite common, it is not regularly tested for — especially in males, who can be asymptomatic carriers.

As for HPV, there is no FDA-approved test for males, meaning that a male can’t usually know his HPV status (although vaccination with Gardasil can give him some assurance that he’s been immunized against the four most common strains). Pap testing and HPV DNA tests can detect evidence of HPV in females — but negative results are not considered to be definitive negative diagnoses. HPV is very good at hiding in our cells, and even as we can transmit it to others, the virus itself can easily evade detection by doctors.

While STD testing is important, it isn’t very helpful in allowing you to avoid exposure to HPV. Aside from total abstinence from any sexual contact whatsoever, vaccination is the best protection against HPV. If your partner claims to have tested negative for HPV, he or she might be confused about the STD testing process. When being screened, find out which specific STDs you are being tested for, and ask your partner to obtain the same information.

“Most HPV infections clear within a year or two, anyway.”

According to the CDC, 90 percent of HPV infections go away within two years, which is great! Unfortunately, every year 14 million of us develop HPV infections — which means that even if most of us clear the virus, tens of thousands of us will develop chronic HPV infections. When the numbers are in the millions, even a few percentage points can represent a lot of people!

“Gardasil is too new. We still don’t know if it really works.”

Gardasil has been available since 2006, so it might seem like it’s still too soon to have proven results. However, a lot of exciting data have already surfaced, and they all indicate that the vaccine is incredibly effective.

In Australia, where vaccination rates are much higher than in the United States, the government has been providing free vaccinations to young females since 2007. Four years into the program, genital wart rates fell by 93 percent in females less than 21 years of age, and by 70 percent among women between 21 and 30 years of age. (This is a good argument to vaccinate boys, as genital warts affect males and females equally.)

Because genital warts can appear in just a matter of months — while HPV-related cancers can take two or three decades to surface — the sharp decline in genital warts is an indicator that cancer rates will decline similarly in the future. In fact, Australians are already seeing declines in “precancer” — such as cervical abnormalities that can progress to cervical cancer if left untreated. Another indicator of Gardasil’s efficacy is the decrease in HPV infections Australia has seen since beginning their vaccination program.

The success in Australia is possible thanks to high vaccination rates — but even in the United States, where the vaccination rate is low, recent studies have shown declines in high-risk HPV infections and genital wart incidence among teenage girls, though not as dramatic as those seen in Australia. This bodes well for the future!

“I’ve already had sex, so what’s the point? HPV is so common that I probably already have it.”

Gardasil protects against four strains of HPV, and it’s not a foregone conclusion that anyone who has had sex has already been exposed to these four strains. There is also emerging evidence that natural HPV infections might not confer effective immunity against re-infection — meaning that even if you’ve been infected with one of the vaccine-targeted strains, Gardasil might still boost your immunity. Furthermore, recent research shows that even among females who have already had abnormal Pap results, Gardasil might reduce the recurrence of cervical abnormalities.

“The HPV vaccine is way too expensive.”

Unfortunately, Gardasil comes with a hefty price tag, which could present barriers — even to insured people with prohibitively high co-payments. A federally funded vaccine program expands access for many uninsured Americans, and access will be further increased as the Affordable Care Act is implemented. As preventive care, vaccination will be covered by insurance at no charge to those who qualify (typically, anyone from 9 to 26 years old).

Planned Parenthood health centers offer Gardasil. More information is available at Planned Parenthood and the National Cancer Institute