Published: 2 February 2017

Information for Consumers

Gardasil 9 Questions and Answers

What is human papillomavirus (HPV)?
How common is infection with HPV?
Why is infection with HPV a problem?
How many people get cancers that can be caused by HPV infection in New Zealand?
How does HPV infection cause cancer?
How is HPV infection treated?
How can I protect myself from HPV infection?
How are HPV vaccines given?
How do HPV vaccines work?
What HPV vaccines are available?
Why is Gardasil 9 vaccine on the immunisation schedule (How good is it)?
If I’ve been vaccinated with Gardasil can I be vaccinated with Gardasil 9?
Why is Gardasil 9 vaccination given at age 11 to 12 years?
What is in the Gardasil 9 vaccine?
How safe is the Gardasil 9 vaccine?
What about serious side effects?
Have there been any reactions to Gardasil 9 in New Zealand?
What do I do if I think I, or someone I know, has had a reaction (side effect) to Gardasil 9?
Summary of the benefits and risks of harm with Gardasil 9 vaccination
Test your knowledge

What is human papillomavirus (HPV)?

Human papillomavirus (HPV) is a virus that infects the skin. There are over 150 different types of HPV. Around 40 HPV types can infect the genitals of males and females.

You can catch HPV through skin to skin contact, for example through vaginal, anal or oral sex with someone who has the virus. Not everyone who has the virus has symptoms such as genital warts.

HPV can be caught from a single lifetime partner who has no symptoms.

How common is infection with HPV?

HPV is the most common sexually-transmitted infection. More than three quarters of the sexually active population are infected during their life. It is possible to be infected with more than one type of HPV

Why is infection with HPV a problem?

For most people HPV infection causes no symptoms. In 9 out of 10 infected people the infection goes away within two years.

For 1 out of 10 people the infection does not go away and may eventually cause cancer.

HPV infection can cause:

• cervical, vaginal and vulva cancer in women
• cancer of the penis in men
• cancer of the anus, throat/mouth and tonsils in men and women

The risk of an HPV infection causing cancer is higher if you smoke or are infected with more than one cancer-causing HPV strain.

How many people get cancers that can be caused by HPV infection in New Zealand?

The table shows how many people get different cancers that can be caused by HPV. The numbers show how many new cases in New Zealand there are in a year.

Table 1: Number of cancers that can be caused by HPV infection (numbers from 2014)

*Data on the numbers for each cancer estimated to be caused by HPV infection is from the US.

How does HPV infection cause cancer?

After HPV infects skin cells it starts to make copies of itself. Strains of HPV that can cause cancer make two proteins, which interfere with the normal functions of the skin cells. These proteins allow the skin cells to grow when normally they wouldn’t (become pre-cancerous). When these infected skin cells are untreated they can develop mutations, which help them change into cancer cells.

How is HPV infection treated?

There is no treatment for HPV infection itself.

Genital warts can be treated with Condyline (podophyllotoxin), Aldara (imiquimod), cryotherapy or laser therapy.

Pre-cancerous cervical cells can be removed by cryosurgery (freezing), LEEP (removal of cervical tissue with a hot wire loop) or conisation (surgery with a scalpel or laser to remove cervical tissue).

Around 153 of these procedures are performed per 100,000 women per year in New Zealand (around 3,500 in total).

How can I protect myself from HPV infection?

You can protect yourself by:

• using condoms (condoms protect against all strains of HPV, but may not cover all areas of the skin infected by HPV)
• getting vaccinated (more information below).

Women can protect themselves from cervical cancer by attending their cervical cancer screening appointments. There are no screening programmes for other HPV cancers.

How are HPV vaccines given?

HPV vaccines are given by injection into the arm muscle. Most people get their vaccine at school around age 11 or 12, but GPs can also give the vaccine. The vaccine is free for people aged 9 to 26 years.

If you are under 15 you need two doses given 6 to 12 months apart.

If you are 15 or over you need three doses. The second dose is given 2 months after the first dose. The third dose is given 6 months after the first dose.

How do HPV vaccines work?

Your immune system is made up of cells and tissues that work together to protect you. One of these important cells are called white blood cells (leukocytes). White blood cells can attack bacteria and viruses or they can produce antibodies. Antibodies stick to bacteria, viruses and toxins (antigens) to help to neutralise and kill them.

HPV vaccines contain a small part of the HPV virus called an antigen. This antigen activates your immune system to produce antibodies. This works the same with the vaccine as when you get an infection. These antibodies are then ready in case you do get infected. The antibodies make sure you can get rid of the HPV virus before you get genital warts or cancer.

What HPV vaccines are available?

There are three HPV vaccines approved for use in New Zealand.

Table 2: HPV vaccines

From 2017 Gardasil 9 will be the only vaccine given in schools, and will replace Gardasil in general practices once stocks run out.

Why is Gardasil 9 vaccine on the immunisation schedule (How good is it)?

Gardasil 9 vaccine was tested to see how well it works in clinical trials. All people given Gardasil 9 made protective antibodies to all the HPV strains in the vaccine.

However, Gardasil 9 does not protect against all strains of HPV and does not work if you have already been exposed to the HPV strains in the vaccine.

Clinical trials showed that women who received HPV vaccine (Gardasil or Gardasil 9) were less likely to have abnormal smear tests (or develop precancerous cells in the cervix) than those who had not been vaccinated.

In New Zealand 10 out of every 1,000 women who have not been vaccinated have abnormal smear test results per year.

In clinical trials the effectiveness of Gardasil was estimated at around 43% (prevented precancerous changes in the cervix in 43 out of 100 women).

In studies comparing the effectiveness of Gardasil 9 with Gardasil:

• 2.4 in every 1,000 women per year experienced precancerous changes in the cervix after Gardasil 9 vaccine.
• 4.2 in every 1,000 women per year experienced precancerous changes in the cervix after Gardasil vaccine.

Gardasil 9 was nearly twice as effective as Gardasil.

The length of time that Gardasil and Gardasil 9 are protective for is not yet known. Gardasil has been shown to be effective for 9 years so far. The long term effectiveness is being monitored.

Cervical screening is still recommended for women who are or have been sexually active, even if they have had the HPV vaccination.

If I’ve been vaccinated with Gardasil can I be vaccinated with Gardasil 9?

Yes. A clinical study has been done to show that Gardasil 9 worked in women who had previously had Gardasil. There were no unexpected safety problems in this study.

Revaccination with Gardasil 9 is not funded.

Why is Gardasil 9 vaccination given at age 11 to 12 years?

Gardasil 9 is given at this age because:

• It works better in younger people so only 2 doses are needed (more protective antibodies are made by younger people).
• The vaccine only works if you haven’t been exposed to the HPV strains in the vaccine (through sexual contact).

Giving the vaccine at a young age does not mean that the person getting the vaccine is ready to start having sex.

What is in the Gardasil 9 vaccine?

Gardasil 9 contains a copy of one of the proteins found in each of the HPV strains 6, 11, 16, 18, 31, 33, 45, 52 and 58. These proteins are known as the antigens. They cannot cause HPV infection and do not cause HPV-cancer.

Each vaccine dose also contains:

• 500 micrograms aluminium (known as the adjuvant it helps the immune system respond to the vaccine)
• 9.56 milligrams sodium chloride (table salt)
• 50 micrograms polysorbate 80 (also used in food like ice cream)
• 35 micrograms sodium borate (used here to stabilise the vaccine, also found in some vitamin supplements)
• traces of yeast (yeast is used to make the protein antigens).

Gardasil and Gardasil 9 are made in a similar way to other medicines such as insulin and hepatitis B vaccine.

How safe is the Gardasil 9 vaccine?

The safety of Gardasil 9 has been looked at in the clinical trials which included 15,875 people who had at least one dose of Gardasil 9.

Overall, the type of reactions people had to Gardasil 9 were very similar to Gardasil.

More people had injection site reactions with Gardasil 9 than Gardasil.

The most common side effects (also called undesirable effects, adverse reactions or adverse events following immunisation) to Gardasil 9 are shown in Table 3 below.

Table: 3 Adverse reactions to Gardasil 9

These adverse reactions are minor and usually go away within a few days.

There is a summary of possible side effects in the consumer medicine information and the data sheet.

What about serious side effects?

One to three people in every million (1-3 in 1,000,000) who are vaccinated with Gardasil 9 have a serious allergic reaction. This is why you are asked to wait after vaccination. The person giving you the vaccine is trained to deal with allergic reactions.

One in every one hundred thousand people (1 in 100,000) who are vaccinated with Gardasil or Gardasil 9 each year develop symptoms of nerve damage such as numbness, weakness and difficulty walking (known as Guillain-Barré Syndrome and acute disseminated encephalomyelitis.

Guillain-Barré Syndrome and ADE also occur in 1 in every 100,000 people who haven’t been vaccinated. These disorders are usually caused by infections such as influenza which cause the persons own immune system to attack their nerves.

There has been some concern that HPV vaccines can cause Postural Hypotension Tachycardia Syndrome (POTS), Complex Regional Pain Syndrome (CRPS) and Chronic Fatigue Syndrome (CFS). Medsafe has reviewed the data on these concerns and found that there was no evidence that HPV vaccination caused these issues.

During the clinical studies there were 7 deaths (out of 15,875 people).

• One woman committed suicide.
• One woman died in a car accident.
• One woman died unexpectedly nearly two years after completing vaccination.
• One woman with previous ovarian cancer died.
• Three women with leukaemia died, one had been diagnosed before being vaccinated and one was diagnosed nearly 4 years after completing vaccination.

These deaths were thoroughly investigated, none of them were caused by the HPV vaccine. They represent the unfortunate circumstances that sometimes occur in teenagers and young adults.

Have there been any reactions to Gardasil 9 in New Zealand?

Reports of suspected adverse reactions to all medicines can be found using the Suspected Medicines Adverse Reaction Search (SMARS). Additional information is also published on the Medsafe website.

What do I do if I think I, or someone I know, has had a reaction (side effect) to Gardasil 9?

The person affected should contact their doctor.

You can also report side effects to the Centre for Adverse Reactions Monitoring (CARM).

Reporting any suspicions of an adverse reaction after having a vaccine or taking a medicine helps CARM and Medsafe monitor the safety of medicines and to take action if a problem is identified.

Summary of the benefits and risks of harm with Gardasil 9 vaccination

Gardasil 9 is approved for use in New Zealand by Medsafe because the benefits of vaccination outweigh any risk of harm.

The summary of the main benefit of vaccination and the most common adverse reactions are shown in Table 4 below.

Table 4: Benefits and risks of harm for Gardasil 9

It will take some time to work out how many cancers HPV vaccination stops.

Vaccination protects the person being vaccinated and their contacts. Some people with impaired immune systems may not get full protection (for example because of cancer treatment or organ transplant).

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