Almost everyone carries the , and it's usually pretty harmless. But a few strains are the main cause of cervical cancer. Gardasil, the HPV vaccine first approved by the FDA in 2006, guards against two of these strains, plus two other strains that are responsible for most genital warts. Two other vaccines were later approved by the FDA: Gardasil 9 and Cervarix. Today, Gardasil 9 is the only one in use in the United States, according to the National Cancer Institute. In addition to the four strains Gardasil protected against, Gardasil 9 also prevents infection from five additional cancer-causing types of HPV.

Since most adults have already been exposed to HPV, the vaccine is recommended for pre-teens who haven't become sexually active yet. The Centers for Disease Control and Prevention (CDC) recommends vaccination at age 11 or 12, but Gardasil 9 can be started as early as age 9.

So far, so good. But the introduction of this vaccine stirred up a small fuss that lingers even today.

What's the controversy?

Perhaps the main fear of the vaccine's opponents is that it might encourage adolescent promiscuity.

H. Hunter Handsfield, MD, a clinical professor of medicine at the University of Washington and a nationally recognized STD expert, believes most parents are all for it, however. "It can prevent cancer?" he says, parroting the most common parental concern. "Well, duh, give my kid the shot."

Still, questions come up all the time because the vaccine is so new. Here are a couple of the most common:

Should boys get the HPV vaccine?

Originally, the HPV vaccine was only approved in girls. The thinking was that men rarely got cancer from HPV. But they do pass the virus to their female partners, they do get genital warts from HPV, and in men (and women).

The CDC now recommends that boys also get vaccinated at 11 or 12, and males who have not been vaccinated adequately can receive the shots up to age 21.

Men who have sex with men and trans folks are advised to get vaccinated through age 26.

RELATED: 17 Things You Should Know About HPV

What about people over 26?

On Friday, the FDA approved the HPV vaccine Gardasil 9 for women and men aged 27 through 45.

While adults have frequently already encountered some strains of HPV by that age, the vaccine can still help prevent cervical cancer and genital warts. "People who have already been infected with one or more HPV types can still get protection from other HPV types in the vaccine," according to the CDC. 


The FDA approval means that older adults who previously would have had to pay out of pocket for the vaccine will now likely be covered by insurance. 


If you're older than 26 and considering the vaccine, it makes sense to evaluate your sexual history. "Say there's a 28-year-old woman, she's about to be out there dating again, and she's only had three or four partners; she probably is still susceptible," says Dr. Hansdfield. "She needs the vaccine."

RELATED: How Often Do You Really Need a Pap Test?

If I get vaccinated, do I still need to get regular Pap smears?

Yes! Experts agree that the vaccine does not replace the need for regular cervical cancer screening, since it only protects against some strains of the virus that cause cervical cancers.