HPV vaccines

The HPV vaccine protects against the human papilloma virus (HPV). There are more than 150 types of HPV, categorised by their association with cervical cancer. The low-risk types are more commonly associated with benign changes to cervical cells or genital warts, and the high-risk types can cause cervical cancer.

Currently there are two HPV vaccines available in Ireland, Cervarix® and Gardasil®.

Gardasil is the HPV vaccine administered as part of the school-based immunisation programme in Ireland. It is a recombinant quadrivalent vaccine and it protects against four types of HPV: HPV-6 and HPV-11, which cause genital warts, and HPV-16 and HPV-18, which cause 70% of all cervical cancers.

Gardasil was licensed in Ireland in 2006 and has been offered free of charge to all girls in their first year of secondary school (aged approx. 12-13 years) by the HSE since 2010. The World Health Organisation (WHO) recommends vaccinating girls aged between 9 and 13 with two doses of HPV vaccine (6 months apart) to help prevent cervical cancer.

Cervarix is a bivalent vaccine that protects against HPV-16 and 18. It was approved for use in Europe in 2007 and in the USA in 2009. The main clinical trial for Cervarix studied 19,000 women aged between 15 and 25, comparing those vaccinated with Cervarix, and those vaccinated with a vaccine that did not protect against HPV. The trial showed that it effectively protected against HPV-16 and 18.

Its safety was tested in 24,000 girls and women and showed common side effects such as redness, swelling and soreness at the injection site, and headaches. Cervarix is administered in two doses. More information about this vaccine can be found on our Resources page.

The WHO estimates that more than 1 million women worldwide are living with cervical cancer (cancer of the cervix, which is the neck of the womb).

More than 30,000 women die from cervical cancer in Europe annually, and the deaths in lower income countries are much higher (270,000 women died from cervical cancer in 2012, with more than 85% of these deaths in lower income countries). The WHO aims to vaccinate more than 30 million girls in 40 countries worldwide by 2020 to dramatically reduce the number of deaths from cervical cancer.

In Ireland every year, 6,500 women receive treatment for pre-cancer of the cervix, 300 women are diagnosed with cervical cancer, and 90-100 women die from cervical cancer. The HPV vaccine will reduce cervical cancer rates and the rates of other genital cancers. There is a link between HPV infection and other genital cancers in both men and women; because of this, some countries (including Australia, New Zealand, and the USA) have included boys in their immunisation programmes to halt the spread of HPV.

Even with vaccination, cervical screening is still vitally important as the current HPV vaccines do not protect against all types of HPV. Additionally, if the rate of vaccination is too low then HPV will continue to be spread throughout the population, putting vaccinated and unvaccinated girls at risk.

No vaccine is 100% effective, but we can make them close to 100% effective by creating a herd immunity and preventing the spread of the virus throughout the population. Vaccinated people act like an umbrella, shielding the vulnerable (including newborns and immunocompromised people such as those fighting cancer) from the spread of infection.

Gardasil is used routinely in 25 countries in Europe, the USA, Canada, Australia and New Zealand, and in over 65 countries worldwide. More than 205 million doses had been administered globally by July 2016. In Ireland, Gardasil had been given to 200,000 girls (660,000 doses in total) by the end of 2016.

Unfortunately, the rates of vaccination against HPV in Ireland have reduced over the past year. This is in part due to some widespread misconceptions regarding the safety of the vaccine (please see later section ‘Testing the safety of the Gardasil HPV vaccine’ for a more detailed discussion).

A reduced rate of vaccination puts all girls, vaccinated and unvaccinated, at risk of contracting HPV and developing cervical cancer. It takes about 15 to 20 years for cervical cancer to develop after infection with HPV, and a much shorter time if your immune system has been weakened.

Gardasil 9 is a more recent HPV vaccine, licensed for use in the USA in December 2014 and in Europe in June 2015. It protects against 9 types of HPV - 6, 11, 16, 18, 31, 33, 45, 52 and 58. It was tested in five large clinical trials, in more than 20,000 people (male and female) of varying ages. The USA are switching to Gardasil 9 from Gardasil in June 2017.

The side effects reported were similar to those seen with Gardasil, with slightly more reactions at the injection site (redness, soreness etc.). Gardasil 9 is administered in two doses. More information about this vaccine can be found on our Resources page.

Most common side effects are mild and temporary. They are a result of the child's immune system responding to the vaccination, and making antibodies that will protect the child in the future. Most side effects will ease after a day or two and any discomfort can be treated with over-the-counter medicines such as paracetamol or ibuprofen (ask your pharmacist for medicine appropriate for your child's age).

Before getting the vaccination, speak to your doctor if your child has been sick over the past few days. Illness can reduce the effectiveness of a vaccine. The nurse or doctor administering the vaccine will check your child’s temperature first, to see if they may have any other infections or illnesses.

Common side effects that are usually no cause for concern: pain, redness or swelling at the injection site, headache, dizziness, nausea, mild fever. Sometimes adolescents, particularly girls, can faint after an injection so they will be asked to sit for 15 minutes after the injection to prevent this.

Other rarer side effects include wheezing or itchy rash/hives. These side effects are rare and have been reported in very few children.

Adverse events are not side effects, though they are sometimes reported in the media as such. These are conditions that occur in someone who is vaccinated but that are not caused by the vaccine (i.e. the rate of the condition is the same in the vaccinated and the unvaccinated populations). Please see the section below (Testing the safety of the Gardasil HPV vaccine) which describes the controversy surrounding adverse events in girls receiving the vaccine.

Remember that the benefits of receiving the HPV vaccine, that reduces your daughter’s risk of developing cervical cancer, hugely outweigh any mild side effects from vaccination.

If you are concerned about your child, contact your doctor or local hospital for advice.

Allergies to substances within vaccines can occur, though they are very rare (they happen in fewer than 1 in 10,000 people receiving the vaccine). An allergic reaction to a vaccine would happen quickly. Signs of an allergic reaction may include itchy skin, rash, shortness of breath and swelling of the face or tongue.

Before getting the vaccination, speak to your doctor or the school immunisation team if your child has experienced any allergic reactions previously.

If you are concerned about your child, contact your doctor or local hospital for advice.

The initial clinical trials for Gardasil were performed in 7,000 females (aged 9 to 45) and 3,000 males (aged 9 to 26) who received the vaccine, as well as a control group who received a placebo (8,000 people). Over 21,000 people were studied before the vaccine was licensed for use, and the studies showed that the vaccine was very effective at preventing infection with HPV-6, 11, 16 and 18, and also at preventing precancerous lesions in the genitals that often develop into cervical cancer. The studies also showed that the vaccine is safe.

Definition of an adverse event:
An adverse event is a medical occurrence that may present during treatment with a pharmaceutical product but which does not necessarily have a causal relationship. This means that the symptoms reported may or may not have been caused by that medicine or vaccine.

Adverse events are closely monitored by the relevant authority (for example the FDA and CDC in the USA and the HPRA in Ireland) who will investigate serious adverse events and determine if they are linked to the medicine/vaccine or not.

All adverse events reported worldwide related to the Gardasil vaccine have been proven to be unrelated to the vaccine. For example, the FDA has been monitoring the Gardasil vaccine since it was licensed in 2006. From June 2006 to December 2008 (during which time 23 million doses of vaccine were administered) there were 772 reports of serious adverse events. After investigation, none of the events reported were linked to the vaccine – the medical conditions were seen at the same rate in the vaccinated population as in the unvaccinated population.

Some of the conditions reported are more common in adolescent girls than in other populations, whether they are vaccinated or not. For example, chronic fatigue syndrome is 3-4 times more common in females than males, and more common in adolescents. The rate of chronic fatigue syndrome reported in girls that were vaccinated with the HPV vaccine in Ireland was actually lower than expected from the rates normally seen in adolescent girls.

All vaccines are continually monitored after they are put on the market and any adverse events are reported by the healthcare professionals and can be reported by members of the public. This is a reliable and interesting article that describes the monitoring of Gardasil in the USA:
Further information on the HPV vaccine can be found on our Resources page.

Vaccinating against HPV is hugely important because of its potential to dramatically reduce cervical cancer deaths in women worldwide.

HSE (Ireland) information on the HPV vaccine:

HSE (Ireland) HPV vaccine factsheet:

Irish Cancer Society information on the HPV vaccine and cervical cancer:

Overview of the safety of the Gardasil vaccine by the FDA and CDC in the USA:

Centers for Disease Control (USA) recommendations for immunisation against HPV:

World Health Organisation overview of HPV vaccination and cervical cancer worldwide:

Information on Gardasil 9 vaccine from the European Medicines Agency:

Information on Gardasil 9 from the National institutes of Health (USA):

Information on Cervarix vaccine from the European Medicines Agency:

Information on Cervarix vaccine from the National institutes of Health (USA):