Vaccines for Cancer Prevention
An oncogenic virus (or oncovirus) is a virus that can cause cancer. These include HIV, HPV (Human Papilloma Viruses), some herpes viruses, hepatitis B and C viruses, Epstein Barr Virus, and retroviruses. It is estimated that 12% of cancers worldwide are caused by viruses. If infection with these viruses can be prevented, these cancers could be prevented as well. In the case of HPV and hepatitis, there are vaccines available to prevent infection with these viruses, but they must be given before a person is exposed to the virus to work.
Hepatitis B Vaccine
- The hepatitis B virus causes liver disease, which can range from a mild illness (that you may not even know you have), to a lifelong illness that can lead to serious liver damage, liver failure, and/or liver cancer.
- Hepatitis B is spread through contact with the blood, semen, or other body fluids of an infected person. It is not spread through water, sharing of eating utensils, coughing, or sneezing.
- The vaccine to prevent hepatitis B is a series of two to three shots, given over 1-4 months.
- It is recommended for all infants, for individuals under age 18 who have not been vaccinated, or anyone who has not been infected or is already immune and is at high risk for infection.
- Almost 100% of cervical cancers and 85% of anal cancers, as well as many vulvar, vaginal, penile, and head and neck cancers, are caused by infection with the human papillomavirus or HPV. HPV also causes most pre-cancerous changes found with pap testing.
- HPV is a virus that can be transmitted through vaginal, anal, and/or oral sexual activity, through skin-to-skin contact - and not necessarily intercourse. It is extremely common – an estimated 80% of sexually active people will contract it at some time in their lives. Most people's immune systems will fight off the infection, but for some, it remains in their system and can lead to abnormalities and possibly cancer.
- There are over 200 "strains" (types) of HPV! Some strains cause genital warts. About 12 strains can lead to cancer.
- HPV vaccination prevents new HPV infection. It does not treat existing HPV infections or diseases.
- In the US, the Gardasil 9 vaccine is used. This prevents against 9 strains of HPV that are linked to cancer. It is given in 2 or 3 doses, depending on the age you are when it is started. The HPV vaccine is recommended for all individuals (boys/men and girls/women) ages 12-26. Individuals between the ages of 27 and 45 can consider HPV vaccination if they were not vaccinated when they were younger. You should discuss this with your healthcare provider.
- The vaccine will not prevent all HPV infections, nor can it treat an HPV infection. For this reason, women should still have cervical cancer screening per their provider's recommendations.
- The vaccine is ideally given before an individual becomes sexually active and is likely to be exposed to HPV.
Both the Hepatitis B vaccine and the HPV vaccine can lower your risk of associated cancers caused by these viruses. In the US, it is estimated that somewhere between 850,000 and 2 million people have chronic Hepatitis B. The younger a person is when infected with hepatitis B, the greater chance it will become a chronic infection, so early vaccination is preferred. For example, nearly 90% of infants exposed to the virus will develop chronic Hepatitis B, but about 95% of exposed adults will recover and not develop a chronic infection.
American Cancer Society, Infections That Can Lead to Cancer: https://www.cancer.org/cancer/cancer-causes/infectious-agents/infections-that-can-lead-to-cancer.html
American Cancer Society, Cancer Vaccines: https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/immunotherapy/cancer-vaccines.html
Chang, M. H. (2009). Cancer prevention by vaccination against hepatitis B. In Cancer Prevention II (pp. 85-94). Springer, Berlin, Heidelberg.
Finn, O. J. (2018). The dawn of vaccines for cancer prevention. Nature Reviews Immunology, 18(3), 183-194.
The Centers for Disease Control: Human Papillomavirus https://www.cdc.gov/hpv/
The Centers for Disease Control: HPV Vaccine Recommendations https://www.cdc.gov/vaccines/vpd/hpv/hcp/recommendations.html
National Cancer Institute, Cancer Vaccines: https://www.cancer.gov/about-cancer/causes-prevention/vaccines-fact-sheet
National Cancer Institute: HPV Vaccines https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-vaccine-fact-sheet