There are more than 40 types of HPV that can infect the anal or genital area. Some genital HPV types can cause genital warts, while others can cause various types of cancer, including:

Cancers of the cervix, vagina, and vulva in womenCancer of the penis in menCancers of the anus and oropharynx (back of the tongue and throat) in both sexes

HPV types 6 and 11 account for more than 90 percent of cases of genital warts, while HPV types 16 and 18 account for about 66 percent of all cervical cancers, according to the CDC. (1) The HPV vaccine that is currently available in the United States, Gardasil 9, protects against HPV 16, 18, 31, 33, 45, 52, and 58, all of which can cause cancer, as well as types 6 and 11, which cause genital warts. The vaccine is made up of noninfectious virus-like proteins (VLPs) that resemble different HPV types but don’t contain live viruses or DNA from HPV. It causes the immune system to produce antibodies to fight the VLPs and the viruses they resemble. Gardasil 9 provides nearly 100 percent protection against cervical precancers and genital warts for at least 10 years.

A Brief History of the HPV Vaccine

Gardasil, the first HPV vaccine to be approved, became available in 2006. Gardasil is called a quadrivalent vaccine because it protects against four types of HPV: types 6, 11, 16, and 18. Gardasil was initially approved for use in girls and women ages 9 to 26. In 2009, the U.S. Food and Drug Administration (FDA) additionally licensed the vaccine for males ages 9 through 26 for prevention of genital warts. The next HPV vaccine approved in the United States, called Cervarix, is a bivalent vaccine that protects against HPV types 16 and 18 and was approved for use in females ages 9 to 26. Gardasil 9 provides nearly 100 percent protection against cervical precancers and genital warts for at least 10 years, with no evidence of protection decreasing over time. In October 2018 the FDA again approved expanding the age indication for Gardasil 9 to include men and women through age 45. The expansion was based on research that showed the vaccine remained 88 percent effective for an average of 3½ years in women ages 27 to 45. Since the approval of Gardasil, there has been a 64 percent reduction in infections with the types of HPV covered by the vaccine among teen girls in the United States. (2) Infections among boys and men have not been studied as extensively as those in girls and women, but at least one study has found that men who have received the HPV vaccine have lower rates of oral HPV infections than those who haven’t. (3)

HPV Vaccine Schedule

The CDC recommends that all boys and girls get the HPV vaccine at age 11 or 12. At this age, most children will not have been exposed to the strains of human papillomavirus that the vaccine protects against, so they will get the full benefit of the vaccine. The vaccine is administered in two or three doses, depending on a person’s age and circumstances. The vaccine produces a stronger immune response when taken during the preteen years than later on, so younger children get the same protection with fewer doses.

Kids who receive the vaccine at age 11 or 12 should get two doses, 6 to 12 months apart. But if the second shot is given less than five months after the first, a third dose will be needed.Teens older than 14 should receive three doses over six months.People ages 9 through 26 who have certain conditions that weaken or impair the immune system should receive three doses.Adults age 27 and older need three shots spaced over several months.

The CDC also recommends the vaccine for any man who has sex with men, and men with compromised or weakened immune systems — including from HIV — through age 26. The Advisory Committee on Immunization Practices additionally recommends HPV vaccination beginning at age 9 for any children or youth with a history of sexual abuse or assault. (4)

Side Effects and Risks of HPV Vaccination

Clinical trials of Gardasil 9 have found no serious safety concerns related to the vaccine, the CDC notes. The vaccine cannot cause an HPV infection or cancer, and there’s no data to suggest it can cause fertility issues. Most people who receive the HPV vaccine don’t experience side effects, while others report very mild side effects, such as a sore arm from the shot. Common side effects include:

FeverNauseaMuscle or joint painHeadacheFatiguePain and inflammation at the injection site

In very rare cases, some people experience a severe allergic reaction to components of the vaccine. As with any medical procedure, brief fainting spells, possibly accompanied by jerking movements, are possible following vaccination, according to the CDC.

What if You Can’t Afford the HPV Vaccine for Your Child?

The Vaccines for Children (VFC) program is a federally funded program that provides vaccines — including the HPV vaccine — at no cost to children younger than 19 who might not otherwise be vaccinated because of inability to pay. To be eligible to receive free vaccines through this program, a child must meet one of the following requirements:

Medicaid-eligibleUninsuredAmerican Indian or Alaska NativeUnderinsured, meaning the child’s health insurance doesn’t cover vaccines or doesn’t cover certain vaccines

While the vaccines themselves are free, some doctors may charge an office visit fee or a fee to administer each shot. Most pediatricians in the United States and its territories are enrolled in the VFC program, meaning they can administer VFC-provided vaccines. But underinsured children can receive VFC vaccines only at Federally Qualified Health Centers (FQHC) or Rural Health Clinics (RHC). For help locating an FQHC, RHC, or VFC program participant, contact your state’s VFC coordinator. Additional reporting by Ingrid Strauch.