When a vaccine became available several years ago that would protect against the human papillomavirus, Sarah Robbins didn't hesitate to have her 13-year-old daughter receive it.
"Medical science has given us a vaccine against cancer," the Hagerstown woman said. "Why would you deny your child such a incredible gift?"
But not everyone feels the same way.
The vaccine has been controversial because the disease it prevents results from sexual activity.
HPV is the most common sexually transmitted disease, with between 75 and 80 percent of females and males in the United States infected at some point in their lives.
Most will overcome the infection with no symptoms or ill effects, according to the Centers for Disease Control. But in some people, infections lead to cellular changes that cause cervical, vaginal and vulvar cancers and cancers of the head and neck. It also is associated with most cases of genital warts.
And while cervical cancer rates have dropped over the years because of widespread screening, anal cancer rates in both men and women have been increasing.
But a series of three shots of Cervarix or Gardasil during an eight-month period has been shown to protect against the HPV strains.
In 2006, after a review of evidence, the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention recommended that girls and young women ages 11 to 26 should be vaccinated.
Since then, public health officials have had limited success, hitting a number of hurdles. Some parents distrust the safety of the vaccines. Others believe that the vaccines promote promiscuous behavior.
CDC statistics show that 49 percent of adolescent girls have received at least the first of the three HPV shots. Only one-third have received all three doses by last year.
It might be a harder sell for boys, now that it's been recommended for them, also.
The CDC's advisory committee recently suggested that the HPV vaccine be given to young males 9 to 26 years old to help prevent the cancer-causing virus.
The reasons for vaccinations are twofold, according to Dr. Frank Mozdy, chief medical officer of Summit Physician Services, an affiliate of Summit Health.
The first, he said, is to identify the people at risk of the disease and vaccinate them before they are exposed to the virus or bacteria.
"HPV is estimated to cause 6.2 million new infections in the U.S. each year," he said. "It is important to offer the HPV vaccine to young women and men before they become sexually active if we want to reduce the number of women with cervical cancer and the number of infected men who can spread the virus."
Also, Mozdy said, vaccines work by what is called "herd immunity." When large numbers of people in a community are vaccinated, the unvaccinated are indirectly protected by having less exposure to the virus.
Mozdy said the vaccine approved for use in boys protects against infection with four of the strains of HPV. Two of the strains cause genital warts.
In addition, "vaccinating males protects females from cervical cancer because the vaccine includes the strains that cause 70 percent of the cases of cervical cancer in women and, it is believed, partial protection against some of the other strains that cause cervical cancer," he added. "The vaccine also protects against strains that cause abnormal Pap smears, precancerous cervical lesions and less common genital and anal cancers."
The HPV vaccine is being offered to boys at most primary care practices in the area, Mozdy said.
And while a CDC survey shows that, in 2010, only 1.4 percent of young males between 13 and 17 years of age had received the vaccine, Mozdy said "several of our busiest family medicine offices have seen an increase in requests for this vaccine for male children."
Summit Health's obstetrics and gynecology and female medicine offices also have reported "a strongly positive response with a large number of young females receiving the vaccine," he said.
One drawback, however, is cost. Without insurance, it can average about $130 per dose or $390 for the full series.
"It is a fairly expensive vaccine," said Dr. L. Stewart Massad, professor of Obstetrics and Gynecology at Washington University in St. Louis.
"It is covered by insurance, but not universally," he said. "Cost is a barrier."
Massad said a child's background can also affect whether they receive the vaccine.
Children in poverty are more likely than those who are not to start a vaccination series but less likely to finish. Blacks and Latinos are also less likely to finish vaccination series than whites. Reasons for this are unclear, he said.