A lot of parents want to know more about the HPV vaccine, so Karin Batty, an immunisation advisor and technical writer at the Immunisation Advisory Centre, gives us the facts.
What is HPV?
Human papillomaviruses (HPVs) are common viruses, and there are more than 150 types. The viruses are easily spread through skin-to-skin contact. Most people won’t even know they are infected, so they can unknowingly spread the infection to others. Some HPV-types cause warts such as those on hands, feet or genitals. Warts can look ugly, but they don’t usually cause any harm. Other HPV types are more serious. Our body’s immune system keeps us healthy fighting off threats like the common cold viruses, but may not be able to get rid of these HPV types. When they infect parts of our body for months or years, they can cause cancer.
Why is HPV a concern?
There are two HPV types that cause almost all genital warts, and seven HPV types that cause around 90% of cancers of the cervix or vagina in women and cancer of the penis in men, and around 90% of anal cancer and 75% of throat cancer in women and men. These viruses are usually spread by skin-to-skin contact during sexual activity. About four out of five people are infected at some time in their lives, usually within the first two years of becoming sexually active.
Preventing HPV infection
The best way to prevent infection from these HPVs is through immunisation before being exposed to them; that is, before becoming sexually active. This is one reason why the vaccine is usually given to boys and girls in Year 8 at school by public health nurses, but can also be given by your GP from nine years of age. Young people’s immune systems have a very good response to the immunisation – so it’s good that young people aged under 15 years only need two doses of vaccine. Adolescents and adults aged 15 years or older need three doses to get the highest protection. We immunise babies to protect them against tetanus long before they are old enough to play in the garden. We immunise adults and children to protect them against influenza before winter, just in case they come in contact with flu viruses. We immunise young people to protect them
against HPV infection, just in case they come in contact with them when they are older.
Gardasil was the first vaccine against HPV; it protected against four HPV types and morethan 216 million doses were distributed worldwide after it was licensed in 2006. Gardasil 9 extends protection, covering nine HPV types, and approximately 10 million doses have been distributed worldwide since it was licensed in 2014. These two vaccines had all the clinical trials to establish they were safe to give and effective before being licensed overseas and here in New Zealand. They have also had extensive vaccine safety reviews of more than six million doses, comparing young people who were immunised with those who were not. There are no concerns about the safety of HPV immunisation.
Vaccine responses and concerns
We expect to see some responses to HPV immunisation. The most common are redness, pain and/or swelling where the vaccine was given, a fever, headache, or feeling tired. Fainting around the time of immunisation is also common, but this relates to the process of having an immunisation rather than the vaccine itself. As with any medicine, a very rare severe allergic response (anaphylaxis) can occur following immunisation. This is why people are asked to wait for 20 minutes after receiving it. Gardasil and Gardasil 9 have received a lot of negative attention over the years, particularly on social media. The stories are either completely untrue or misunderstand the safety data. Extensive worldwide safety reviews have demonstrated how these stories are not caused by the vaccine. The volume of evidence that these vaccines are very safe is overwhelming.
A significant decline in HPV-related disease has been observed in countries that have achieved high coverage of HPV vaccine; for example:
- In Sweden, high-grade cervical lesions declined by 75% in vaccinated women.
- In Australia, genital warts have declined by 90% in young vaccinated women.
As time passes, these successes will see the burden of HPV infection become a thing of the past, around the world and here in New Zealand.
Human papillomaviruses (HPVs) can cause genital warts and cervical, vaginal, penile, anal
and throat cancers.
Immunisation can protect against the nine HPV types that cause the most problems.
In New Zealand the HPV vaccine, Gardasil 9, is free for everyone* from nine years of age until they turn 27 years.
It is usually given to students in Year 8 (age 11 or 12) through a school-based immunisation programme. You can also choose to get it free of charge at your family doctor. *Adults aged 18–26 years must be eligible to receive publicly funded healthcare in New Zealand to start a course of free HPV immunisations.
There’s a world-wide limit on the supply of the HPV vaccine, Gardasil 9. In NZ, teens will still get it at school in year 8, but not from their GP. Eligible high risk groups, (e.g. after organ transplants) can still get it from their GP. Normal supply is expected to resume in September.