FAQ on HPV Vaccines
This page is a selection of different questions that Jo’s Cervical Cancer Trust has received about the HPV vaccine. The answers have been reviewed by Jo’s Cervical Cancer Trust’s medical advisers.
HPV is an extremely common virus. There are over 100 identified types of HPV. Some types of HPV can cause changes in the cells of the cervix creating abnormalities. Once these abnormalities become severe they may develop into cancer.
Girls who are offered the HPV vaccine have an opportunity to protect themselves from two high risk types of HPV that cause at least 70% of all cervical cancers.
Yes, however, there are about 100 types of HPV, divided into those that are 'high risk' and 'low risk' for cervical cancer. The most common types that cause cervical cancer are 'high risk' HPV types 16 and 18. The 'low risk' types do not actually cause cervical cancer, but can cause genital warts. The two commonest low risk types are types 6 and 11.
Cervical cancer and genital warts are caused by different types of HPV, so having genital warts does not mean that you are more likely to get cancer.
Yes, the Gardasil vaccine protects against four HPV types: the two most common HPV types that cause cervical cancer, HPV types 16 and 18 as well as the two most common HPV types that cause genital warts, HPV types 6 and 11. The other licensed vaccine, called Cervarix is designed to protect against high risk HPV types 16 and 18 but not genital warts.
Women need to be vaccinated before they come into contact with the virus. As the virus is transmitted by skin to skin contact, through sexual activity, this age will vary. In practical terms, probably the most effective and easiest way to reach everybody is for girls to be vaccinated during their first or second year at secondary school.
HPV vaccination has been shown to prevent infection and pre-cancer for at least nine years but it is expected to last longer. Ongoing studies will show how much longer you will be protected for and whether booster shots will be required.
Gardasil and Cervarix protect against the two most common HPV types that cause cancer, types 16 and 18. It has been estimated that this will prevent about 70% of cervical cancers. You should note however, that it is important to attend for regular screening even if you have been vaccinated so that abnormalities caused by other HPV types may be detected.
Two HPV vaccines have been developed. Gardasil is developed by MERCK. The other vaccine, Cervarix was developed by Glaxo Smith Kline. Gardasil is the chosen vaccine for the Canadian in school vaccination program.
For more information about the vaccination program for teenage girls click on the relevant link below:
Thousands of girls and women of different ages took part in the clinical trials for the HPV vaccines . These trials found that the vaccine offers 98% protection against infection with the high-risk types of HPV in girls who haven’t previously been infected with the virus. Side effects from both vaccines are usually mild.
Side effects for the Gardasil HPV vaccine include :
Very common side effects (side effects which may occur in more than 1 per 10 doses of vaccine) reported by girls who have received the vaccine are:
- injection site problems such as redness, bruising, itching, swelling, pain or cellulitis
Common (side effects which may occur in less than 1 per 10 but more than 1 per 100 doses of vaccine):
- nausea (feeling sick)
- painful arms, hands, legs or feet
Rare (side effects which may occur in less than 1 per 100 but more than 1 per 1,000 doses of vaccine):
- More than 1 in 10,000 people who have the Gardasil HPV vaccine experience: An itchy red rash (urticaria)
- Fewer than 1 in 10,000 people who have the Gardasil HPV vaccine experience: Restriction of the airways and difficult breathing (brochospasm
Currently, the HPV vaccination program does not cover boys, except in Prince Edward Island, Alberta and Nova Scotia. Cancers caused by HPV in men include anal and penile cancer. Fortunately these are very rare .
The majority of women clear the infection through their immune systems but for those who do not, regular cervical screening tests can pick up abnormalities in cervical cells before a cancer develops. These abnormal cells can then be removed and in the majority of cases this is highly successful. In very few women, changes occur more rapidly, in the interval between cervical screening, or occasionally the changes are not detected by a cervical screening test.
At the present time, there is no vaccine that can treat women after they have been affected.
The vaccine prevents infection. It is not known if people who have been treated in the past will benefit and the vaccine is therefore not recommended in this situation.
HPV vaccines have the potential to reduce the number of cases of HPV associated cancers, and the number of individuals who have to be treated because of these cancers in generations to come. For women who are already part of the screening program, the best protection against cervical cancer is to continue going for regular cervical screenings.
- NHS choices website: http://www.nhs.uk/Conditions/vaccinations/Pages/hpv-vaccine-cervarix-gardasil-side-effects.aspx Accessed 03/05/13.
- Szarewski A. 2008. HPV vaccines: peering through the fog. Journal of Family planning and Reproductive Health Care, 34 (4), 207-209.
"FAQ on HPV Vaccines." Jo's Cervical Cancer Trust. N.p., 19 Aug. 2013. Web. 02 Mar. 2015.