In December 2015, at the age of 47, I was diagnosed with Stage IV oral squamous cell carcinoma.

More simply, I have advanced cancer of the head and neck. While initial treatment with grueling chemo-radiation appeared successful, the cancer returned one year later in both of my lungs. My prognosis shifted from potentially curable to terminal disease. The news was shocking and devastating—not just for me, but for my wife, two teenage daughters, and the rest of our family and friends.

Suddenly, my life revolved around regular appointments for chemotherapy, radiation therapy, imaging procedures, and frequent checkups. I made seemingly endless, unscheduled hospital emergency room visits—including one trip to the intensive care unit—to address some of the more severe toxicities from treatment.

All told, I suffered from more than a dozen side effects related to treatment and/or cancer progression. Some are temporary; others permanent. These include anxiety, depression, distorted sense of taste, clots forming in my blood vessels, dry mouth, weight loss, and many more.

My cancer started with a human papillomavirus (HPV) infection, a virus that is preventable with vaccines available for adolescent girls since 2006 and boys starting in 2011. The Food and Drug Administration (FDA) has approved three vaccines to prevent HPV infection: Gardasil®, Gardasil® 9, and Cervarix®. These vaccines provide strong protection against new HPV infections for young women through age 26, and young men through age 21, but they are not effective at treating established HPV infections. It was too late for me in 2011 when the HPV vaccine was made available to young men, and I was 43 years old.

According to the Centers for Disease Control and Prevention (CDC), more than 30,000 new cancers attributable to HPV are diagnosed each year. Unlike human immunodeficiency virus (HIV), which is spread by blood and semen, HPV is spread in the fluids of the mucosal membranes that line the mouth, throat, and genital tracts, and can be passed from one person to another simply via skin-to-skin contact.

While most HPV cases clear up on their own, infection with certain high-risk strains of HPV can cause changes in the body that lead to six different types of cancer, including cancers of the penis, cervix, vulva, vagina, anus, and head and neck (the last of which is what I have). Two of these, HPV strains 16 and 18, are responsible for most HPV-caused cancers.

Researchers believe that it can take between 10 and 30 years from the time of an initial HPV infection until a tumor forms. That’s why preventing HPV in the first place is so important and the HPV vaccine is so essential.

However, only 49.5 percent of girls and 37.5 percent of boys in the United States were up to date with this potentially lifesaving vaccination series, according to a 2017 CDC report. In sharp contrast, around 80 percent of adolescents receive two other recommended vaccines—a vaccine to prevent meningococcus (PDF), which causes bloodstream infections and meningitis, and the Tdap vaccine to prevent tetanus, diphtheria, and pertussis.

Even if you don’t think your child is at risk for HPV now, they almost certainly will be. HPV is extremely common. Nearly everyone gets it at some point; in fact, the CDC estimates that more than 90 percent and 80 percent of sexually active men and women, respectively, will be infected with at least one strain of HPV at some point in their lives. Around one-half of these infections are with a high-risk HPV strain.

As a cancer patient with a terminal prognosis, I find it infuriating that the HPV vaccine is tragically underutilized more than a decade since its introduction. Two simple shots administered in early adolescence can reduce a child’s risk of receiving a cancer diagnosis much later in life.

Parents who oppose the use of vaccines cite popular misconceptions that they are unsafe, ineffective, and that immunity is short-lived. Others argue that receiving the HPV vaccine may increase sexual promiscuity. Films like Vaxxed based on research that has been discredited, and directed by a researcher who fled the United Kingdom due to the misleading uproar he created, are still quoted as science.

Regardless, the fact remains that millions of adolescents aren’t getting a vaccine to prevent a virus known to cause cancer. We must counter untrue, exposed, and discredited research that keeps some parents from having their children vaccinated and put an end to the campaign of misinformation.

Viruses that are preventable, such as HPV, should be eradicated just like previous success with polio and smallpox. Cancers that are preventable through HPV vaccination should be prevented. The safety and efficacy of these vaccines are no longer subject to serious debate (PDF). Research has shown that vaccinations work; they keep children healthy, save lives, and protect future generations of Americans—but only when they are utilized.

The lesson: Don’t wait. Talk to your pediatrician about vaccinating your 11-year-old boys and girls against HPV today to eradicate this cancer-causing virus.

I only wish my parents had that opportunity when I was young, as it could have prevented the cancer that’s killing me.