AOGQ - Association of Obstetricians and Gynecologists of Quebec

15 Octobre 2011

Human Papilloma Virus (HPV) Vaccine

Gardasil™ and Cervarix™
Two HPV vaccines are available in Canada: Gardasil™ and Cervarix™.

Gardasil™, which protects against HPV types 6, 11, 16, and 18, is for girls and women between the ages of 9 and 45 years. It is also the only vaccine indicated for boys and men between the ages of 9 and 26 years. This vaccine has been offered free of charge since 2008 under the provincial vaccination program. Free vaccination is available to girls ages 9 to 17 years and women ages 18 to 26 years who are immunosuppressed or HIV positive. It particularly provides protection against cervical cancer caused by HPV types 16 and 18 as well as against genital warts (condylomata) caused by types 6 and 11. The vaccine is not available to boys at no charge.

Cervarix™ provides protection against two types of HPV: 16 and 18. It is indicated for girls and women ages 10 to 25 years, but is not free of charge in Québec.

Both HPV vaccines are safe. Most reactions to them are benign and short-lived. Moreover, the benefits from preventing cancer and other complications largely outweigh any disadvantages.

Vaccine efficiency

Protects against certain cancers

HPV vaccination protects against infection caused by types 16 and 18, which are responsible for 70% of cervical cancers as well as other cancers such as anal, vaginal, and penile cancer. If the person has not already been infected by one of the types of HPV contained in the vaccine, the protection against cervical cancers caused by them is nearly 100%. This is why vaccination is recommended before the onset of sexual activity. The vaccine can be administered even after the onset of sexual activity, since it is very unlikely that the person has already been infected with the different types of HPV at the same time.

The vaccine used in Québec's vaccination program also protects against infections resulting in anogenital warts (condylomata) caused by types 6 and 11. Most people will be unaware they have become infected with HPV, since they will not have any symptoms, which increases the risk of transmission. The vaccine is indicated even if the person already has an HPV infection, because a person can be infected more than once or by different types of HPV.

Vaccinated women must continue having Pap smears to screen for cervical cancer, because vaccination does not offer protection against the types of HPV not contained in the vaccines. The vaccine is safe and effective.

Number of doses required

Three doses are needed to obtain good protection. Under the school vaccination program, an extended schedule is used for vaccination of fourth graders: two doses are administered in grade 4 elementary school and the third dose in Secondary 3. In the case of adolescents and adults, the doses are given over six months to achieve rapid protection.

The manufacturer recommends a single vaccination schedule, consisting of the three doses administered over six months. Québec experts, however, deem that the extended schedule in grade 4 elementary school will provide protection comparable to the manufacturer's recommendation. Administering the third dose in Secondary 3 has the added advantage of ensuring optimal protection around the age of onset of sexual relations.

Vaccine protection last for several years. Studies are underway throughout the world to assess long-term protection. If necessary, a booster shot could be given to maintain protection.

Side effects of the vaccine

The HPV vaccine is safe and vaccination results in few side effects. There are effective means for alleviating the pain and discomfort of vaccination. Ask the person administering the vaccine about them.

Possible Reactions to the Vaccine

Possible Reactions to the Vaccine	Action
Pain (50% or more), redness, swelling (10% to 49%), or itching (1% to 9%) at the injection site	Apply a cool, moist compress to the injection site.
Headache (50% or more), mild fever, nausea, vomiting, dizziness, diarrhea, joint pain (10% to 49%) Discomfort, insomnia, redness, hives (1% to 9%)	Take a medication such as acetaminophen or ibuprofen for a fever of 38.5°C or more. Consult a physician, depending on the severity of symptoms.

Symptoms occurring after vaccination are not necessarily caused by the vaccine. As with all medications and biologicals, allergic reactions are possible. If any severe allergic reaction were to occur, which is very rare, it would be within a few minutes of vaccination and the person administering the vaccine would know what to do. This is why it is recommended to wait on site for 15 minutes after being vaccinated.

As of now, more than 50 million doses of HPV vaccine have been administered worldwide. Current data show that the same unusual side effects had already been observed in past scientific studies and that they are benign in most cases. Québec has a system for monitoring the side effects of any and all vaccines used. All vaccinators are required to declare any adverse reactions observed after vaccine administration.

Most of the side effects reported range from mild to moderate in severity, and are primarily allergic-type clinical symptoms or local reactions (pain and swelling) at the injection site.

Many other countries also collect data about vaccine side effects and safety. They mainly provide regularly updated information that relates vaccines to severe adverse effects and death. To date, no link has been established between HPV vaccines and certain severe diseases or death.