Cervical cancer vaccine Gardasil can cause an allergic reaction

Sep 8 2008

According to Australian researchers, the cervical cancer vaccine Gardasil can cause an allergic reaction in some girls.

Gardasil protects against the human papillomavirus (HPV) which is responsible for some cancers and in 2007 the Australian National Human Papillomavirus Vaccination Program meant the vaccine was offered free to all women aged 12–26 years.

The researchers from the National Centre for Immunisation Research and Surveillance at Westmead's Children's Hospital, say while the vaccine is safe, there have been some cases of potentially life-threatening allergic reactions.

Their study of 114,000 young women who were given the vaccinations in NSW last year has revealed that there were 12 suspected cases of anaphylaxis, a potentially life-threatening allergic reaction that can cause breathing difficulty, nausea and rashes.

Of the dozen cases, eight were confirmed as anaphylactic reactions to the vaccine - seven of the eight cases were from 269,680 doses of HPV vaccine administered in schools.

The adverse effects equated to around of 2.6 per 100,000 doses, as against a rate of 0.1 per 100,000 doses in a 2003 school-based meningitis vaccination program and is also higher than the rates for other vaccines given at schools such as hepatitis B, diphtheria, measles, mumps and influenza.

The lead author Dr. Julia Brotherton says nevertheless the potentially serious risk with the HPV vaccine was extremely low and can be managed with adrenalin injections or other treatment.

Dr. Brotherton says parents can be confident that these reactions were very rare and are not a reason to not vaccinate their daughter against HPV.

Dr. Brotherton suggests the higher rate of reactions could be due to possible allergic reactions to vaccine components, better surveillance, higher rates of anaphylaxis in adolescent girls and an apparently general increase in the number of incidents of anaphylaxis.

However the Therapeutic Goods Administration (TGA) says it is important that healthcare professionals and patients are made aware of the risk as anaphylaxis and allergic reactions are not predictable and can occur in anyone regardless of whether they have a previous history of allergy.

The TGA says it has received 1,013 reports of suspected adverse reactions to Gardasil, but still supports the use of the vaccine.

In recent months there have been some serious questions raised regarding the effectiveness of the vaccine and how long it's effectiveness lasts, and also whether it would deter women from attending screening programs; there have also been suggestions that it may possibly interfere with the body's natural defence against other HPV strains.

The researchers say the HPV vaccination of 12-year-old girls was cost-effective, whereas catch-up immunisation programs for women up to 18, 21, or 26 years of age were not.

Other organisations who were involved in the research include the University of Sydney, the Adelaide Women's and Children's Hospital, and the New South Wales Department of Health.

The research is published in the Canadian Medical Association Journal.