What is human papillomavirus (HPV)?
The human papillomavirus (HPV) is a virus that spreads through sexual intercourse, oral sex, anal sex and also sexual touching (hand to genital contact). HPV is the most common sexually transmitted disease in Canada. Most people do not know that they have HPV because they do not have any symptoms. Unfortunately, they can still pass on the virus to their partner. Persistent HPV infection can lead to certain types of cancers.
HPV is very common. About one in four Canadians under the age of 25 have HPV.
There are many different strains of HPV. The HPV vaccine protects against the four most common strains:
- The strains HPV-6 and HPV-11 cause genital warts.
- HPV-16 and HPV-18 are the leading cause of cancers of the cervix, which is the lower part of the uterus that narrows into a canal and opens into the vagina. These strains can also cause cancers in the penis and anus as well as cancers of the head and neck.
In Canada, two vaccines can protect against HPV: Gardasil and Cervarix.
How can the HPV vaccine help protect against HPV?
Gardasil protects against four types of HPV:
- HPV-16 and HPV-18, which cause about 70 percent of all cancers of the cervix
- HPV-6 and HPV-11, which cause about 90 percent of all genital warts
Gardasil can be prescribed to females between the ages of nine and 45. The vaccine is licensed for use in males age nine to 26. It offers protection against certain cancers of the penis, anus, head and neck. It also protects the partners of males who have had the vaccine. Unfortunately, the cost of the vaccine for boys is not yet funded by most public health programs.
Cervarix protects against HPV-16 and HPV-18. It is given to females between the ages of 10 and 25.
Both vaccines require three doses to be given over the course of six months (Cervarix is given at zero, one and six months; Gardasil is given at zero, two and six months). In Canada, one of the vaccines is given to females in school in Grade 4-8, depending on the province (see table below).
Important facts about the HPV vaccine
There are many common misconceptions about the HPV virus and vaccine. The correct information is provided below so that you have all the facts when discussing sexual health and the HPV vaccine with your child.
The HPV vaccine is not a substitute for regular checkups
The vaccine protects against some types of HPV that can potentially lead to cancers. Regular checkups with the doctor are still important. About 30% of cervical cancers will not be prevented by the vaccine because it does not cover all HPV strains. Women should continue to be screened for cervical cancer with pap smears, even after getting all three shots of either HPV vaccine.
The vaccine cannot treat HPV infections or HPV-related disease
HPV vaccine helps prevent HPV-related infections or disease but will not treat an infection. It is most effective in women who are not yet sexually active because they are less likely to have contracted an HPV infection.
There is currently no medical cure for the HPV virus
Once someone is infected it can take weeks to months before genital warts become apparent. Warts inside the vaginal or anal areas may not be obvious. Some home therapies and other treatments in the doctor's office can be used to treat warts, but none can completely eliminate the virus. Even if the warts disappear, the virus can remain and warts recur. When warts are treated it can take 8 months or longer for them to disappear.
HPV vaccines do not protect against other sexually transmitted infections
The HPV vaccine protects against genital warts, which is one type of sexually transmitted infection (STI). It cannot protect against all types of STIs, such as HIV, chlamydia, or gonorrhea. It is important to practice safe sex. Parents should advise teens on how to reduce their risk of contracting STIs.
The HPV vaccine will not make your child more promiscuous
There is no evidence that giving the vaccination will increase sexual activity.
The HPV vaccination is an opportunity for parents to discuss sex and health with their children. Parents should be talking about sex with their children regularly.
Studies show that sex education does not increase sexual activity. In fact, sex education may decrease early sexual activity, especially if the message encourages delaying sex and having protected sex.
Can sexually active females benefit from the vaccine?
The vaccines are most beneficial when given to girls before becoming sexually active. For this reason, doctors usually prescribe HPV vaccines to girls between the ages nine and 13. However, few sexually active women are infected with all types of HPV. For this reason, the vaccine can still help prevent infection and can be given to girls older than 14 years of age. A person with HPV usually has it for life. However, the vaccine can still help prevent recurrences.
Is the vaccine protection long-lasting?
Studies show that people exhibit strong immunity against HPV. Scientists do not know exactly how long the vaccine protects again HPV because long-term studies have not been done, but protection is for at least five years.
Are the HPV vaccines safe?
Studies show both HPV vaccines are safe. For both vaccines, the most common side effect is soreness at the site of injection. This is temporary.
The only reason not to get the vaccine would be if you have had an allergic reaction to a previous dose of the vaccine or if you are pregnant.
The vaccines contain particles from part of the virus. They cannot infect you with HPV. The vaccines also do not contain any antibiotics or preservatives, such as mercury or thimerosal. Cervarix contains a new additive called (ASO4). According to Health Canada, ASO4 is safe.