Vaccination is the best protection against infections caused by HPVs and their complications.
HPV vaccines (Cervarix, Gardasil and Gardasil 9) protect against HPV 16 and 18, which are responsible for most HPV-related cancers, such as cancer of the cervix, vagina, vulva, penis, anus and throat.
The vaccines used in the vaccination program (Gardasil et Gardasil 9) also protect against genital warts, which are caused by infections from certain types of HPVs. Genital warts are the most common sexually transmitted infections in Canada.
Very often, people infected with HPV do not have symptoms. A person can therefore be infected without knowing it.
What Are the Vaccines Made from
HPV vaccines stimulate the immune system to prepare antibodies against these viruses. They are made from parts of the viruses that are unable to infect the person who is given the vaccine. In other words, these vaccines cannot transmit a HPV infection.
Like many other vaccines, HPV vaccines contain an adjuvant, which is used to increase the immune system’s response to the vaccine. HPV vaccines do not contain any preservatives, latex, antibiotics, thimerosal or mercury.
HPV vaccines are developed in accordance with the usual process prescribed by Health Canada. This process regulates and oversees vaccine research, manufacturing, licensing, efficacy and safety. All vaccines must go through this process in order to be distributed in Canada.
For more information, consult How Vaccines Work.
Number of Doses Required
Depending on the person’s age, 2 or 3 doses of the vaccine are required over a 6-month period. For people under 18 years of age, experts believe that 2 doses of HPV vaccine (1 dose of Gardasil 9® followed by 1 dose of Cervarix®) will produce a sufficient immune response.
Based on various studies, experts believe that these 2 vaccines will produce a very strong immune response to HPV types 16 and 18. HPV 16 is responsible for most HPV-related cancers, especially cancers that affect men. Furthermore, these 2 vaccines provide immunity against the 7 other types of HPV in the Gardasil 9® vaccine.
The manufacturer has never submitted the Cervarix® vaccine for approval for use in boys in Canada. However, scientific data, including from a study conducted in Québec, show that this vaccine is safe and produces a similar immune response in boys and girls.
People aged 18 or older need 3 doses of Gardasil 9®. These vaccines are more effective when the person being vaccinated has never had a HPV infection. Since the infection usually occurs in the first years of sexual activity, the vaccine should ideally be given before the person becomes sexually active. These vaccines are nonetheless indicated for people who have already had a HPV infection or lesion.
Vaccination is not a substitute for cervical cancer screening.
Duration of protection
Protection lasts for a number of years.
Studies are being conducted around the world to evaluate long-term protection. There is no indication that a booster dose is necessary at this time.
Benefits of HPV Vaccination
Vaccination has been proven effective in reducing, or even eliminating, some serious diseases. This is also true of HPV vaccination.
In many countries, a significant decrease in precancerous cervical lesions and warts has been seen since vaccination was introduced. A study conducted in Québec also showed a significant decrease in the number of cases of warts since the introduction of vaccination, particularly in groups of girls targeted by vaccination.
A study conducted in Québec showed that rates of infection with the types of HPV in the vaccine were much lower in vaccinated women than in non-vaccinated women. Furthermore, these types of HPV were nearly absent in women who had been vaccinated before they became sexually active.
Although there is usually a long period between HPV infection and the development of cancer, studies have already started to show that the vaccine is highly effective against cervical cancer.
For men who do not have a HPV infection when they vaccinated, the vaccine’s efficacy rate:
- Is 90% for preventing warts
- Is almost 80% for preventing precancerous or cancerous lesions of the genitals, anus or throat
However, the vaccine’s efficacy rate is lower in people who are already infected when they are vaccinated.
Recent studies show that the vaccine could, however, prevent the reappearance of anal lesions in men under the age of 26 who are already infected with one of the HPV types in the vaccine at the time of vaccination. No data are available for men over 26 years of age.
Symptoms after Vaccination
Some symptoms may be caused by the vaccine, e.g. redness at the injection site. Other problems may occur by chance and are not related to the vaccine, e.g. cold, gastro, headache.
HPV vaccines are safe. Most symptoms or reactions are benign and and do not last long.
|Frequency||Known reactions to the vaccine|
In most cases
The Cervarix® vaccine causes a little more pain, redness and swelling at the injection site than the Gardasil 9® vaccine.
To date, over 270 million doses of HPV vaccines have been administered worldwide. According to current scientific data, no serious or unexpected problems are associated with these vaccines. No link has been found between this vaccine and certain serious diseases or deaths.
The side effects of HPV vaccination are being studied worldwide. The Ministère de la Santé et des Services sociaux monitors side effects of the HPV vaccine. As for all immunization programs, the monitoring of side effects is done through the Programme de surveillance passive des effets secondaires possiblement reliés à l’immunisation (ESPRI).
What to Do after Vaccination
Tips to follow immediately following vaccination
Wait 15 minutes before leaving premises where vaccine is received. If an allergic reaction occurs, the symptoms will appear a few minutes after the vaccination.
If you feel side effects, immediately inform the person giving the vaccine. That person will be able to treat you immediately.
Tips to follow at home
If you experience redness, pain or swelling at the injection site, apply a cold, damp compress on it.
Use medication for fever or discomfort if needed.
When to Seek Medical Help
See a doctor if one of the following applies to you:
- You experience serious and unusual symptoms
- Your symptoms get worse instead of improving
- Your symptoms last over 48 hours
Last update: 24 October 2018, 13:36