Cancer Vaccine Causes Allergic Reactions
Researchers reported Monday, that Australian women who got a vaccine to prevent cervical cancer were five to 20 times more likely to have a rare but severe allergic reaction.
That’s compared with girls who received other vaccines in comparable school-based vaccination programs.
Researchers found severe allergic reactions to the human papillomavirus or HPV vaccine were unusual and manageable and they noted the vaccine remained safe.
The team of Australian researchers led by Dr. Julia Brotherton of The Children’s Hospital at Westmead studied 114,000 young women vaccinated with Merck & Co’s Gardasil vaccine.
Their vaccination was part of a 2007 vaccination program in New South Wales.
They reported in the Canadian Medical Association Journal that of the women studied, 12 had suspected cases of anaphylaxis, a potentially life-threatening allergic reaction that can cause difficulty breathing, nausea and rashes.Â
Eight out of the 12 young women had confirmed anaphylactic reactions after getting the vaccine.
That averages an estimated rate of reaction of 2.6 per 100,000 doses administered. That compared with a rate of 0.1 per 100,000 doses in a 2003 school-based meningitis vaccination program.
Researchers suspect the higher rates of allergic reaction could be due to better surveillance programs to watch for such reactions.
Nevertheless, scientists say anaphylaxis remains rare, and they encourage use of the vaccine.
It targets four strains of the human papillomavirus, a common sexually transmitted virus that causes genital warts and most cases of cervical cancer.
"It’s just a reminder that there are rare adverse effects," said Dr. Neal Halsey of Johns Hopkins University in Baltimore.
"It doesn’t change the strong recommendations for all adolescent girls to get this vaccine but we just have to watch them to make sure they don’t have this allergic reaction," said Halsey.
During May 2007, the U.S. Centers for Disease Control and Prevention said Gardasil has been linked with a higher risk of fainting, in some cases resulting in injury.
Merck distributed more than 16 million doses of Gardasil in the U.S., which is approved for women and girls ages 9 to 26.
Image Courtesy Merck Frosst Canada Ltd.
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