No one likes shots, but there's one shot for kids that's been a particularly tough sell — for their parents.

The latest numbers from the National Immunization Survey show a slight dip in the number of Minnesota girls getting the HPV vaccine — which state health officials say protects both boys and girls against the human papillomavirus (HPV) virus, which can cause cancer.

"We are not seeing the HPV rates in adolescents and in our young people, age 11 and 12, that we are with the other vaccines [such as those for whooping cough and meningitis] that are recommended," said Annie Fedorowicz, adolescent immunization coordinator for the Minnesota Department of Health.

That has prompted state health officials to step up efforts to reach out to both parents and doctors to tell them about the importance of protecting young people from the virus. Pharmaceutical companies have gotten into the act, too, with one edgy crusade in particular designed to ramp up parental angst.

Merck, which makes Gardasil, one of the most common HPV vaccines, launched a provocative television ad campaign last summer aimed at parents of adolescents. The ads, which still are shown regularly, feature children speaking directly to their parents about the risk of getting cancer from HPV.

In one typical commercial, images of a boy at different stages of his young life flash on screen as he narrates: "I was infected with HPV. Maybe my parents didn't know how widespread HPV is. While HPV clears up for most, that wasn't the case for me. Maybe they didn't know I would end up with cancer because of HPV. Maybe if they had known there was a vaccine to help protect me when I was 11 or 12. Maybe my parents just didn't know."

The boy then looks right into the camera and asks: "Right Mom, Dad?"

Some of the objections to the shots are similar to other anti-vaccination concerns over possible side effects. But in this case, there's another aspect in play: Because the HPV virus is transmitted sexually, some parents fear that having their child vaccinated could be interpreted by the youngster as tacit approval of sex.

"Some people perceive this as a vaccine that prevents STDs," said Jennifer Heath, education and partnership unit supervisor for the state health department. "The research is showing that this is not encouraging sexual activity earlier. It's really important for them to understand that this vaccine has proven to be safe, that the research shows that it's incredibly effective at preventing cancer."

HPV infections are the most common sexually transmitted infections. There are no symptoms and the virus often goes away on its own within a couple of years. But in some cases, it can cause cervical cancer in women and penile cancer in men, as well as anal cancer, throat cancer and genital warts in both men and women, officials from the Centers for Disease Control and Prevention (CDC) say.

Statewide, the percentage of girls between 13 and 17 who received at least one dose of the HPV vaccine dropped from 65.5 percent in 2015 to 58.1 percent in 2016, the National Immunization Survey found. But more Minnesota boys were vaccinated — with the percentage of 13- to 17-year-olds rising from 57 to 60 percent.

In addition, the CDC reports that many young people are not getting the full dosage of the vaccine, which is administered in a series of shots. They are stopping partway through the series, which does not adequately protect them from the virus, the agency said.

The CDC recommends the vaccine for children and young adults between 11 and 26. For children 11 or 12, two doses are recommended. Young people who begin the vaccine series between ages 15 and 26 require three doses, the CDC says.

Parents are worried

Those who are opposed to the HPV vaccine raise questions about its effectiveness and safety. Potential side effects include: redness or swelling in the arm where the injection was given, fever, headache and fainting. The CDC notes that on very rare occasions, anaphylactic allergic reactions may occur after vaccination.

Kacey Rasmussen, of Orono, decided not to have her younger daughters vaccinated after her oldest had a severe reaction to the vaccine.

Her brain swelled after the first dose, and she began to lose her vision. Years later, her daughter is still suffering from the effects, Rasmussen said. Her daughter, now 25, was recently diagnosed with Postural Orthostatic Tachycardia Syndrome (POTS).

"It impacts her heart. Every time she sits up or moves from lying down to sitting up, her heart races," Rasmussen said.

"We're not an anti-vaccine family by any means," she added, noting that her children have received other vaccines.

And then there's the sex issue. The CDC recommends giving the shot to children as young as 11 because that's when their bodies have the strongest immune response. But some parents and providers shy away from discussing the vaccine because it's dealing with a virus that is transmitted through sexual contact.

Those concerns didn't scare off Deb Landon of Minneapolis, who did not hesitate to make sure her kids received the full dose of the HPV vaccine.

"We did it without question," she said of the decision to vaccinate her son when he was 12. "We followed the schedule recommended by the doctor." Her son, now 14, has not experienced any side effects, she said.

While she understands that some parents are squeamish about thinking about their children and the risk of sexually transmitted infections, Landon is not one of them.

"We believe in the value of early and accurate sexuality education, so we did not view it as opening a door to promiscuity or sexual activity," she said. "My logic was simply that at one point they will become sexually active."

Allie Shah • 612-673-4488 • @allieshah