HPV and Vaccination
Human Papillomavirus (HPV) Prevalence in the General Population
• HPV infections are very common. The prevalence of HPV infections in young adult females can range between 30 and 80 %, and the lifetime probability of ever encountering HPV is as high as 80–90 %.
• The risk of HPV infection increases significantly after first sexual debut.
• HPV infection normally has no signs or symptoms, so it is very difficult to determine if someone has a current infection.
• More than 90 % of people infected with HPV will clear their infection eventually but, given the number of HPV infections, governments and communities need to take steps to protect people.
• The HPV vaccine is safe and effective in protecting populations from the HPV strains most closely associated with cervical cancer development.
HPV Infection is a Normal Part of Becoming a Sexually Active Adult
• HPV infection can be passed on at the first sexual debut — it is not a result of sexual promiscuity.
• Research suggests that two in five women would be worried what people thought of them if they were told they had HPV. Cervical cancer services need to help address this stigma.
• The HPV vaccine does not lead to increased sexual activity or increased sexual debut in either men or women.
• Cervical cancer can develop in women who have not recently been sexually active. WHO estimates that it takes 15–20 years to develop cervical cancer for women with normal immune systems, or 5–10 years for women with weaker immune systems (like those living with untreated HIV).
• HPV vaccines offer protection against cervical and other HPV-associated cancers but not against other sexually transmitted infections.
• While important in the protection against sexually transmitted diseases, condoms offer only very limited protection against transmission of HPV.
More than 95 % of Cervical Cancers are Caused by Human Papillomavirus Infection
• Almost all cases of cervical cancer are caused by HPV.
• HPV types 16 and 18 are responsible for at least 70% of cervical cancer cases globally, while a further five types are responsible for a further 20% of the global burden. In total, IARC has identified 13 types that are linked to cervical cancer.
• HPV vaccines are a safe and effective way of reducing risk of infection with higher-risk HPV strains.
• All available HPV vaccines protect against HPV types 16 and 18.
• The most common types of cervical cancer are not hereditary.
Human Papillomavirus Vaccines are Safe and Effective in Preventing HPV Infections, Precancerous Lesions and Invasive Cancers
• The HPV vaccine protects against the most common cancer-causing strains of HPV but not against all. It can also provide some protection from developing HPV-related cancers at other sites.
• The HPV vaccine is safe. Over 12 years of vaccine safety monitoring and more than 160 studies have shown that HPV vaccines have a favorable safety profile, including no impacts on future fertility for girls who are vaccinated.
• Studies show that the HPV vaccine reduced the incidence of cervical cancer by 90% among vaccinated women compared with unvaccinated women.
• Because of the time between initial HPV infection (prevented by vaccines) and the development of cervical cancer, initial studies used pre-cancer as an endpoint. Most experts expected that this would ultimately result in prevention of cancer and following 10 years of research we now have clear evidence of the vaccine’s preventive effect.
• A combination of HPV vaccination and screening provides the best protection.
Vaccinating girls aged 9–14 could prevent 30–40% of cervical cancer deaths between 2015 and 2030
• HPV vaccines work best if delivered prior to exposure to the virus. The World Health Organization recommends vaccinating girls aged 9–14, when most have not started sexual activity.
• Lesbian and bisexual women are an often-overlooked risk group for HPV infection, even though the virus can be transmitted between female sex partners.
• The HPV vaccine is safe. Over 12 years of vaccine safety monitoring and more than 160 studies have shown that HPV vaccines have a favourable safety profile, including no impacts on future fertility for girls who are vaccinated.
• The average age at diagnosis for cervical cancer is about 47 years and 70% of cancers are diagnosed in women under the age of 60 who have not participated in regular cervical cancer screening.
Cervical Cancer Screening is a Safe and Effective Way to Identify Pre-Cancer or Cancer at an Early Stage when Treatment is Easier and Has Fewer Side-Effects
• HPV vaccination does not replace cervical cancer screening. Countries with the HPV vaccine also need population-based screening programs to identify and treat precancerous lesions and invasive cancers.
• Cervical cancer screening is conducted among women who have no symptoms and may feel perfectly healthy. This is because HPV can remain dormant for long periods of time so, even if you have not been sexually active for a long time, you can still have the virus.
• WHO recommends that countries use HPV tests to screen as this saves more lives and is more cost-effective. Screening with an HPV test should start from 30 years in the general population and 25 years for women with HIV.
• Recent developments mean that women can painlessly collect their own sample using a small swab, overcoming many barriers to cervical screening.
• The average age at diagnosis of cervical cancer is 53 and so screening prior to this point increases the chances of identifying cancer early.
• There is no data to show a link between conducting HPV tests and loss of fertility in women, and treatment of early-stage disease can be carried out while preserving fertility. However, it is much more difficult to achieve this with later-stage cancers.
Source: Conquering Cervical Cancer in the Commonwealth: Addressing Myths and Misconceptions
The Commonwealth and Union for International Cancer Control, June 2022