Human Papillomavirus (HPV) Prevention and HPV Vaccine: Questions and Answers

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What is HPV?

There are over 100 types of human papillomavirus (HPV). HPV is a virus that can infect many parts of the body . Some types of HPV are sexually transmitted and can cause ano-genital warts in both men and women. The types of HPV that infect the ano-genital area are not the same as the ones that infect other areas such as the fingers, hands and face. Other types, not related to ano-genital warts, can very rarely cause cervical cancer in women and anal or penile cancer in men.

Some types of HPV are referred to as “low-risk” viruses because they rarely develop into cancer. HPV types that are more likely to lead to the development of cancer are referred to as “high-risk.” It is important to note however that most women with high-risk HPV will not develop cervical cancer.

How can you protect yourself from getting HPV?

For females four of the common types of HPV can be prevented through vaccination. This is important given that there is no treatment available which can cure an HPV infection. HPV vaccines have been in development for many years and one of the vaccines has recently been approved for use in Canada ( July 11, 2006). The vaccine was licensed in the United States (US) on June 8, 2006. This vaccine protects from infection with 4 of the most common types of HPV (Types 6, 11, 16 and 18). HPV vaccines are currently being studied for use in men.

To reduce the risk of acquiring an HPV infection, always use a condom during sex. While condoms don’t eliminate the risk of infection, u sing a condom, consistently and properly, during vaginal, anal and oral sex will decrease the chance that you will get HPV or pass it on to your partner. A condom will only protect the area it covers so it may be possible to become infected by any uncovered warts (for example, on the scrotum).

Using a condom will also help to protect you from other sexually transmitted infections and reduce the chances of unintended pregnancies.

Other ways to reduce your risk of infection are to delay sexual activity (waiting until you are older), to limit your number of sex partners and to consider your partners sexual history if they have had multiple previous partners.

Who should get the vaccine?

Canada
The vaccine has been approved for use in Canada for females 9-26 years of age. The schedule is three doses at 0, 2 and 6 months. Recommendations for use, which come from the National Advisory Committee on Immunization (NACI), are not yet available.

US
The vaccine has been licensed by the Food and Drug Administration for females 9-26 years of age. The Advisory Committee on Immunization Practice recommends routine vaccination of 11-12 year old females. The vaccination series can be started as young as 9 years of age. Vaccination of females 13-26 years of age is also recommended for those who have not been previously vaccinated or who have not completed the full series (3 doses). Since HPV is a sexually transmitted infection, ideally, the vaccine should be administered to females before they become sexually active. However, the recommendations also indicate that women who are already sexually active can also benefit from the vaccine if they are not already infected with HPV.

What does the vaccine protect against?

The vaccine will protect against infection with two high-risk types of HPV (16 and 18) and two low risk types (6 and 11). HPV types 16 and 18 cause approximately 70% of cervical cancers. HPV types 6 and 11 cause approximately 90% of ano-genital warts.

The vaccine does not protect against any other types of low or high risk types of HPV. The HPV vaccine will not have an impact on an existing infection.

How effective is the vaccine?

The HPV vaccine has demonstrated a very high efficacy in preventing the four types of HPV infection mentioned above (HPV types 6, 11, 16 and 18).

If you are infected with one of the four HPV types in the vaccine, the vaccine will still protect against the other types. The HPV vaccine will not have an impact on an existing infection. Talk with a health care professional for more information.

Is the vaccine safe?

Yes, the vaccine is safe and few side effects were reported among the participants in the recent studies for the vaccine. The most common side effect was a brief soreness at the site of injection. Also, you cannot become infected with HPV from the vaccine and the vaccine does not contain any mercury or thimerosal.

Will girls/women who have been vaccinated still need cervical cancer screening?

The HPV vaccine does not protect against all types of HPV, it only protects against the most common types of HPV that cause cervical cancer and ano-genital warts. Even when someone is vaccinated it is still possible to become infected with one of the less common types of HPV that the vaccine does not protect against. Therefore, it is important that vaccinated girls/women continue to have regular Pap tests. Pap testing should be started at age 18 as part of a routine health examination, or earlier—as soon as one becomes sexually active. For more information, see the “It’s Your Health” Fact Sheet on screening for cervical cancer
[ http://www.hc-sc.gc.ca/iyh-vsv/diseases-maladies/cervical-uterus_e.html ].

How long does vaccine protection last? Will a booster shot be needed?

Recent studies have indicated good protection against HPV for five years of follow-up. Studies are ongoing to determine if further immunization is necessary for vaccinated women to have continued protection.