HPV Vaccines: An update
HPV stands for Human Papilloma Virus. It is a very common virus and consists of a group of 200 types of related viruses.
More than 40 HPV types can infect the genital areas of males and females. They are spread through intimate contact during vaginal, oral or anal sex. The infection is very common and nearly all sexually active men and women will get it at some point in their lives. It happens more often in those who have many sexual partners or in those who have sex with an infected partner. But a person with only one sexual partner can also get HPV infection.
HPV vaccine has significantly reduced precancerous lesions and genital warts among young people according to research studies published in 2019. This means fewer people in the future will develop cancers linked to HPV, including cervical cancer, anal cancer, and some mouth and throat cancers.
However, many women are still unclear about the types of vaccine, their efficacy and risks of vaccination as well as who and when should the vaccine be given. I have collated them in the following Q&A format.
What are the vaccines available?
There were 3 different vaccines available (Cervarix®, Gardisil®, Gardisil9®)
Cervarix® vaccine protects against HPV types 16 and 18 (responsible for 70% of cervical cancer).
Gardasil® vaccine protects against HPV types 6,11 (responsible for warts) and types 16, 18
Gardasil®9 vaccine protects against HPV types 6, 11, (responsible for warts) 16, 18, 31, 33, 45, 52 and 58(responsible for 90% cervical cancer)
These vaccines do not contain a live virus and thus they are noninfectious and cannot give a person HPV.
What are the risks of a vaccine reaction?
Most people vaccinated do not have serious reactions.
Common reactions include:
Soreness, redness or swelling at the site of injection
Fainting spell after vaccination
Severe allergic reaction is very rare, estimated at about one in a million doses.
Anyone allergic to the ingredients in the HPV vaccine should not get the vaccine, including severe allergy to yeast. It may happen within a few minutes to a few hours after the vaccination.
Can the vaccine help prevent HPV?
HPV vaccines are extremely effective in preventing infection by the HPV types they cover. It reduces a woman’s risk of cervical cancer and precancerous growths substantially. In men, the vaccine may prevent genital warts, penile cancer, anal cancer, and the spread of HPV to sexual partners.
Since they do not protect against all HPV infection, it does not prevent all cases of cervical cancer. It does not treat or cure an HPV infection in women or men who are already infected by one of these HPV types.
Who should be vaccinated against HPV and when?
HPV vaccine produces the strongest immune response in preteens. According to the Advisory Committee on Immunization of USA, routine vaccination for girls and boys should start at age 11 up to 26 years old. From 11 to 15 years old, two doses are given at 0 and at 6 to 12 months. From 16 to 26 years old, 3 doses are administered at 0, 1 or 2 and 6 months.
Recently, Gardasil®9 vaccine had been expanded to include people between the ages of 27 and 45. Research has suggested there may still be benefits to getting the vaccine at a later age.
How long will the vaccines last?
HPV vaccines have been shown to provide excellent duration of protection for the periods through which they have been studied. Continued protection has been observed at least 10 years following vaccination. Further data will become available in the future as female and male participants in vaccine studies are followed over time.
If a woman has had HPV infection, can she still be vaccinated?
Women who have evidence of present or past HPV infection may be vaccinated. Studies have shown that the vaccines may have some therapeutic effects as the recurrence of cervical pre-cancerous lesions may be reduced.
Can pregnant women receive HPV vaccine?
The HPV vaccine is not known to be harmful to pregnant women or their babies. However, until more information is known, pregnant women are advised not to receive the HPV vaccine.
Women who are breastfeeding can safely receive the HPV vaccine.