context: When the FDA approved the first human papillomavirus ( HPV) vaccine in 2006, it was big news. The new HPV vaccination made headlines at the time, which wasn't surprising, given that it was the very first vaccine approved to prevent cervical cancer. Yet, even though the HPV vaccine has been around for years, not everyone knows exactly what it is or what it does. You might be wondering: How does it work? Is it safe? Should you or your child get it? So you can be more confident when you talk to your doctor about the HPV vaccine, here are answers to these and other common questions about the vaccine. HPV stands for human papillomavirus. It's a virus that can be transmitted through sexual contact. During intercourse or oral sex, HPV can make its way into the genitals, mouth, or throat and cause infection. Sexually transmitted HPV comes in more than 40 different varieties. The type of the virus you get determines what effects it has on your body. Certain types of HPV cause genital warts. Other HPV types can make cells turn cancerous. You've probably heard that HPV causes cervical cancer, but it also causes less common cancers of the vulva, vagina, penis, anus, head, and neck. What's tricky about HPV is that it doesn't have symptoms. There's no sore throat or fever to let you know you've been infected. Most people clear the infection on their own. In fact, you might have absolutely no idea you've been infected until you develop genital warts or have an abnormal Pap test. Though HPV might not be as well known among sexually transmitted infections ( STIs) as herpes or syphilis, it is actually the most common STI. If you're sexually active, there's a very good chance of being infected with HPV at some point in your life. That's why immunization is so important. Three vaccines are available to protect against the types of HPV that cause most cervical, vaginal, vulvar, penile and anal cancers. They are Gardasil, and Gardasil 9. They also protect against most genital warts. Whichever of these vaccines you and your doctor choose, you should stick with the same vaccine for all three shots. Whether you have to get vaccinated depends on your age and where you live. In certain states, girls and boys within the recommended ages may need to get the HPV vaccine in order to go to school. Getting vaccinated could help lead to the reduction of the prevalence of HPV infection. HPV is known to cause cervical, vaginal, vulvar, penile, and anal cancer, as well as cancer of the back of the throat. Cervical cancer alone kills about 4,000 women each year in the U. S. One in four persons in the United States is infected with HPV and most of them are unaware. It spreads easily among infected partners. Gardasil prevents HPV-16 and HPV-18, which is responsible for 70% of all cervical cancers, as well as HPV- 6 and HPV-11, which are known to cause 90% of all genital warts. Gardasil 9 also protects against these four HPV strains, as well as five others. The best time to get the HPV vaccine is before you've started having sexual activity. That's why the CDC recommends that both boys and girls get their vaccination at age 11 or 12, although they can get the vaccine as early as age 9. If you're 13 or older and you haven't already been vaccinated, you can still get the vaccine through age 26. Gardasil 9 can be given to both males and females until age 45. The Gardasil vaccine isn't recommended for people over age 26, because it hasn't been studied well enough in this age group. If enough future studies show that it is safe and effective for people over 26, the FDA may eventually start recommending it for this age group. The FDA has approved the use of Gardasil 9 for males and females up to age 45. You'll get three shots of the HPV vaccine over a 6-month period. You need to take all three doses to be completely protected. You'll get the second shot about 1 to 2 months after the first, and the third shot 6 months after the first. Once you've started with a vaccine brand ( Gardasil or Gardasil 9), stick with it for all three shots. No. If you have a current HPV, the vaccine won't get rid of the infection. However, if you have one type of HPV, the vaccine may prevent you from getting another type of the virus. There's really no way to treat the virus once you have it, although there are treatments for diseases caused by HPV such as genital warts and genital cancers. This is why you should have regular pelvic exams and Pap tests (if you're female) to screen for cervical cancer. The vaccine appears to offer long-term protection from HPV. However, even women who have received the vaccine should see their gynecologist regularly for a Pap test to check for cervical cancer, because the vaccine doesn't protect against all HPV types that can cause cervical cancer. Most insurance plans cover routine vaccines, which means that if you're in the recommended age group, your insurance should pay for the vaccine. Check with your insurance company just to be sure. If your family doesn't have health insurance or you're on Medicaid, you should be able to get the HPV vaccine for free through the Vaccines for Children ( VFC) program. Vaccines have to be rigorously tested before they can be widely distributed. The HPV vaccines were tested on thousands of people and shown to be safe before they were released to the public. These vaccines have been used for years now, and experts say the chance of them causing a serious reaction is very slim. The HPV vaccine does not contain mercury or the preservative thimerosal. Some people shouldn't get the vaccine. You definitely don't want to get the HPV vaccine if you've had a serious allergic reaction to it or to any of its components. Let your doctor know if you have any severe allergies to anything, including baker's yeast or latex. Also, talk to your doctor if you have an immune system problem or blood disorder. If you're pregnant, you'll want to wait to get the HPV vaccine until after your baby is born. In studies, HPV vaccines have not been found to cause any problems in babies whose mothers got the vaccine while pregnant, but pregnant women should not get HPV vaccine, as safety studies are still ongoing. You could have side effects, but they should be mild. Most people who complain of symptoms after getting the HPV shot have minor issues like pain or swelling at the site of the shot, fever, headache, and nausea. Sometimes people faint after getting the HPV vaccine or any other vaccination. Sitting down after getting the shot can help prevent you from passing out. No. The part of the HPV virus used in both vaccines is inactivated (not live), so it can't cause actual HPV infection.