HPV vaccine could prevent thousands of cervical cancer cases each year. A doctor explains

CNN

2 days ago

Imagine if there were a vaccine for breast cancer, lung cancer, prostate cancer, uterine cancer, ovarian cancer or any of the most well-known cancers that sicken and kill so many people.
Every year, there are an estimated 48,000 new cases of cancers associated with the human papillomavirus, or HPV, in the United States, according to the US Centers for Disease Control and Prevention. But in the case of HPV, there actually is a vaccine.
Yet public awareness remains low. Over one-third of American adults are unaware of HPV or the HPV vaccine, according to a new research letter published Thursday in JAMA Oncology. In some states, the numbers are significantly higher.
That's why people need to know about HPV, the cancers linked to the virus, and the effectiveness of the HPV vaccine.
To help with these questions, I spoke with CNN wellness expert Dr. Leana Wen. Wen is an emergency physician and adjunct associate professor at George Washington University. She previously was Baltimore's health commissioner, and she is the mother of two young children.
CNN: What is HPV, and what cancers is it linked to?
Dr. Leana Wen: HPV is a virus that can infect humans. There are over 100 types of HPV. Most HPV infections aren't linked to cancer, but some are. The specific types of cancers associated with HPV infection are cervical cancer, cancers of the vagina, vulva, penis and anus. Some oral and throat cancers are also associated with HPV infection.
Of the cancers linked to HPV, cervical cancer is the most common. Each year in the US, there are about 13,000 new cases of cervical cancer. About 4,000 American women die of this cancer annually. However, as referenced in the new report, it's not just cervical cancer — there are as many as 48,000 new cancer diagnoses linked annually to HPV. It's important for people to understand the association between HPV and cervical cancer as well as the link to other cancer types, including the link to oropharyngeal cancers.
CNN: Do people know if they have HPV — do they have symptoms at the time?
Wen: Some types of HPV cause warts. These tend to be what's called low-risk HPV, meaning HPV that is not linked with cancer. Infections with high-risk HPV do not cause symptoms at the time of infection; symptoms can develop later when precancerous and cancerous cells develop.
According to the National Cancer Institute, HPV infection is very common — so common that nearly all sexually active people become infected with HPV within a few years of becoming sexually active. As much as half of HPV infections involve high-risk HPV.
Most HPV infections are cleared by the body and do not result in cancer. However, some high-risk infections can persist. Over the course of many years, it can lead to the development of precancerous and then cancerous cells.
CNN: How is HPV spread?
Wen: The most common way for HPV to spread is through sexual intercourse. The virus can also spread during close skin-to-skin contact during intercourse.
It's crucial to understand just how widespread HPV is and how high-risk HPV is spread by asymptomatic people. Condoms can lower the risk of spreading HPV, but because HPV can infect areas that condoms don't cover, they don't fully protect against HPV. This is why vaccination is so important, to protect against HPV-causing cancers down the line.
CNN: How effective is the HPV vaccine?
Wen: The HPV vaccines have very high efficacy — close to 100% — for the prevention of cervical cancer in women, according to the CDC. The vaccines have also been found to have very high efficacy in men who have sex with men in preventing anal cancer. The vaccines also reduce the likelihood of developing genital warts.
CNN: When is the vaccine recommended to be given?
Wen: The CDC recommends that preteens receive the first dose of the vaccine at age 11 or 12, though it can be given as early as age 9. For most people 9 through 14, a two-dose series is recommended, with the second shot given six to 12 months after the first. A three-dose series is recommended for people who begin vaccination at ages 15 through 45 and for immunocompromised individuals. The second shot is given one to two months after the first and the third about five months later.
CNN: I have heard some parents say that they don't want their children to get the shot because it may encourage them to have sex earlier. How do doctors and public health experts respond to that concern?
Wen: They would point to the data. A large study published in the journal JAMA Internal Medicine compared over 21,000 vaccinated girls with nearly 186,000 unvaccinated peers and found 'no evidence of increased unsafe sexual behavior.' Other studies have found no association between HPV vaccination status and age of first sexual encounter or number of sexual partners.
Because high-risk HPV is so widespread, protecting against the cancers it can cause is essential. We are fortunate to have a vaccine that is so effective. Giving the vaccine is not about encouraging a particular behavior, but about giving protection in case someone becomes exposed to a virus someday.
CNN: What is your takeaway from this latest report?
Wen: Awareness of HPV and the HPV vaccine remains dangerously low among the general public. In seven states, more than 40% of adults were not aware of HPV; in 13 states, more than 40% were unaware of the vaccine. In 45 states and Washington, DC, more than 60% did not know that HPV could cause oral cancers.
The authors concluded that 'there is a critical need to enhance HPV awareness among adolescents, young adults, parents or caregivers, and pediatric and adult health care professionals.' I agree.
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