Australia reports unusual reaction to HPV shots
September 2, 2008
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Helen Branswell
THE CANADIAN PRESS
Australian researchers have observed a higher than expected rate of a severe allergic reaction called anaphylaxis in young women who have received the HPV or human papillomavirus vaccine, Gardasil.
Anaphylactic reactions are typically seen in about one case in one million vaccinations for many vaccines. But during the HPV vaccination program in New South Wales in 2007, anaphylaxis was reported at a rate of about 2.6 cases per 100,000 vaccinations, the researchers said yesterday in the Canadian Medical Association Journal.
The lead author of the study said she and her colleagues could not determine what was behind the higher-than-normal rate of allergic reactions. But Dr. Julia Brotherton insisted the findings shouldn't deter parents from getting their daughters vaccinated.
"This is still vanishingly rare. And it's easily treated if it's recognized rapidly," Brotherton said from Sydney, where she is a public health physician with Australia's National Centre for Immunization Research and Surveillance.
Anaphylaxis is an allergic reaction involving hives or an itchy rash, a quickening heart beat and wheezing or breathing difficulties. The condition sets in rapidly and is generally triggered by exposure to a food or drug to which a person is allergic, or the sting of insect.
All of the girls recovered after being treated with epinephrine, also known as adrenaline. None experienced the most serious – and life-threatening – form of the condition, anaphylactic shock.
Merck Frosst Canada – the Canadian subsidiary of Merck & Co., which makes Gardasil – said in a statement that the safety profile of the vaccine "remains excellent."
The elevated rate of anaphylaxis seen in New South Wales hasn't been mirrored in North America, public health officials said.
"We've seen no confirmed reports of anaphylaxis in Canada," said Dr. David Butler-Jones, Canada's chief public health officer.
"The rates are still exceedingly low," he said of the Australian rate. "It's still a very good and safe vaccine."
Side effects reported in Canada are similar to those reported in the U.S., Butler-Jones said – things like acute tenderness at the site of the injection and some cases of fainting.
Dr. John Iskander, acting director for immunization safety at the Centers for Disease Control in Atlanta, said that the U.S. reporting system for adverse reactions to vaccinations isn't picking up evidence of elevated rates of anaphylaxis among American girls who have received the HPV vaccine.
Toronto Star