To understand why some parents have chosen not to protect their kids from measles, consider why parents shun another well-tested vaccine, which would protect children from a number of devastating forms of cancer. While more than 700 people have been infected by this latest measles outbreak in the US, thousands of young people are unnecessarily being infected with cancer-associated strains of human papillomavirus (HPV). These will slowly, quietly, cause cancer in some of them years later.

“The anti-vaxxers really hate the HPV vaccine,” says Stewart Lyman, a cancer researcher who wrote a provocative opinion piece for the medical website STAT, connecting opposition against vaccines to an often-deserved public distrust of the pharmaceutical industry. He included a long list of breaches of trust — from high drug prices to bungled clinical trails to lies about the alleged safety of opioids.

When I called Lyman, I found his primary concern related to vaccines is HPV. Though a vaccine has been available since 2006, less than half of girls and only 38% of boys in the US are getting it, according to the Centres for Disease Control and Prevention. Meanwhile, the cancer-causing strains of HPV currently infect at least one in five US adults.

For years the virus was associated exclusively with cervical cancer, which can often be caught early with regular screenings. It was a female problem. But today the most common HPV-associated cancer is oral cancer, and for this there is no standard screening test. More than 18,000 cases are diagnosed each year, and most of them are in men.

In 2016, Lyman said, he was diagnosed with an HPV-associated cancer in his tonsils, and he suspects that he might have picked up the infection as a teenager.

Mercola and misinformation

The virus raises the risk of a number of less common cancers as well, none of which can be easily caught early through screening. It’s terrible that so many people are stuck with this virus, but wonderful that the younger generations don’t have to be. The vaccine has been tested and given widely in Australia with no evidence of serious side effects. Why skip it?

The answer becomes clear from a Google search for HPV vaccine and risks, which brings up reputable information from the American Cancer Society, quickly followed by a dramatic essay by Joseph Mercola, who is known for spreading distrust of mainstream medicine and promotion of vitamins.

The American College of Pediatricians ... [is] a misleadingly named advocacy group with a right-wing agenda, focused primarily on preventing same-sex couples from adopting kids

The Mercola piece is just the kind of thing that might appeal to people with a strong suspicion of the drug industry. There are dozens of risks listed for the HPV vaccine — from fainting spells to pain to several cases where girls developed ovarian problems and possible infertility.

The key to recognising this as misinformation is in the references. The infertility paper was a case history written by doctors who didn’t think the problem was caused by the vaccine, but wanted this noted in case a pattern emerged. None of the papers he cited were claiming that the vaccine caused a problem.

Mercola also referenced a statement advising against the HPV vaccine by the American College of Pediatricians. This sounds damning, because readers could easily assume this is the primary professional organisation for pediatricians. It isn’t. It’s a misleadingly named advocacy group with a right-wing agenda, focused primarily on preventing same-sex couples from adopting kids.

The spreaders of disinformation can take advantage of the diligence of the US government in collecting data on adverse reactions. If a person receives the vaccine and later develops some illness, this goes in a database even though the events are unlikely to be connected. The purpose of collecting the data is to flag anything that might look like a pattern.

One antidote to Mercola and those of his ilk would be to help separate people’s scepticism of big pharma from their judgment of disease risk. Consider how we might look at the disease symptoms if they were side effects of a drug.

Imagine, for example, there was a drug with a well-documented risk of permanently inserting genetic material into cells in various parts of your body, where it would hide for years, and without warning might emerge as cancer. Those who were unlucky would die, and those who were relatively lucky might be cured with disfiguring surgery, painful radiation and devastating chemotherapy. Would you choose those risks for someone you cared about?

Similarly, if measles were a documented side effect of a medication, parents wouldn’t want anything to do with it.

Parents who would avoid a treatment with such a risk of cancer or measles should also be averse to skipping the vaccines.

Such a thought experiment might not change the minds of the most vocal anti-vaccine activists, but it could help the much larger number of parents who want to do the right thing but are confused and unsure. The decision not to receive a well-tested vaccine is reckless, just like taking a drug known to be harmful. Cautious, sceptical parents who think this through will err on the side of vaccinating.

• Flam is a Bloomberg Opinion columnist. This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.