Reactions to HPV vaccine safe
After being given to over 23 million
females, the results so far suggest that the
HPV vaccine is quite safe.
Image: iStockphoto

Three years after the Gardasil vaccine was licensed in the US to protect against the human papillomavirus, or HPV, research shows there have been few serious reactions to the 23 million doses administered to Americans.

The research published in the Journal of the American Medical Association reveals that fewer than 1 per cent of patients - 54 people out of 100,000 vaccinated, experienced side effects most commonly including headaches, nausea and dizziness.

Of the adverse reactions reported through the Vaccine Adverse Event Reporting System, 6.2 per cent were deemed to be serious with 32 deaths included. While, the deaths were reported after patients had received the HPV vaccine, they have not been attributed to the vaccine.

As of 31 July 2009, more than 81,000 New Zealand girls and young women had chosen to have the HPV immunisation, with 40 per cent of women born in 1990 or 1991 who have been eligable to receive the vaccine for free having done so.

The latest data from the Ministry of Health in New Zealand gathered by the Centre for Adverse Reactions Monitoring based at the University of Otago, comes to conclusions similar to those outlined in the JAMA research.

According to the Ministry of Health, 146,955 doses of the HPV vaccine are recorded on the National Immunisation Register as having been administered in New Zealand to 30 June 2009. A total of 155 suspected adverse events following HPV immunisation had been received by CARM in the period to June 26.

The majority of reactions included "soreness, swelling or redness at the injection site, raised temperature, headache, nausea, skin reactions - mostly rash and fainting," according to CARM. Fainting incidents were described in 17 reports.

Only one case is classified by Medsafe as "serious". According to the Ministry of Health:

"This report related to the hospitalisation of an individual with a pre-existing condition two weeks after immunisation. The likelihood of this event being caused by the vaccine is still being evaluated, but it appears unlikely."

On the research published in JAMA, Helen Petousis-Harris, Director of Research at the Immunisation Advisory Centre at the University of Auckland comments:

"The Immunisation Advisory Centre at The University of Auckland was pleased to see the recently published update of post-licensure safety data for Gardasil. There have been an estimated 23 million doses of the vaccine administered in the US, and this new data continues to demonstrate the vaccine's excellent safety profile.

"Most adverse events reported were not considered serious and included injection site reactions, headaches and nausea. Syncope (fainting) after receiving the injection was not uncommon, but as other research has demonstrated, was not associated with the vaccine itself.

"The data comes from the US vaccine adverse event reporting system (VAERS). This is a 'passive' system in that both health professionals and the public are encouraged to report any adverse event that occurs following a vaccine, regardless of the severity, reason for, or timing of the event. Passive systems do not therefore look to attribute any cause for the event, but are an early warning system that looks for unexpected trends in adverse events that may warrant further investigation."

The Ministry of Health's chief advisor for population health, Dr Greg Simmons, comments on the progress of the HPV vaccination programme:

"As cervical cancer develops over many years, the benefits of the programme in reducing cervical cancer rates will not be evident for some time although the reduction in HPV infection and abnormal cervical changes will be apparent much sooner."

"Young women who are taking up the programme are taking a positive step that will reduce their risk of developing cervical abnormalities or receiving an abnormal smear test result when they are older." 

Editor's Note: Original news release can be found here.