Australia’s drug regulator widened an investigation into CSL Ltd.’s seasonal flu vaccine, the first to include the H1N1 pandemic strain, after the shot was linked to fevers and convulsions among children.
The Therapeutic Goods Administration asked the nation’s eight states and territories to examine all reports of fevers among children under 5 years, even cases not directly involving vaccination, for evidence of a pattern that may help explain the incidents, Kay McNiece, a spokeswoman for the regulator, said in a telephone interview from Canberra today.
The regulator said April 23 that children aged 5 and younger should stop receiving CSL’s Fluvax and the company said it stopped distributing the product after complaints of seizures and fevers among children. The reports of possible side effects may deter parents from vaccinating their children even if the shot is shown to be safe, said Alan Hampson, chairman of the Australian Influenza Specialist Group.
“There’ll be collateral damage,” Hampson said by telephone. “It’s a bit of a disaster not only here, but globally, in casting apparent doubts on the vaccine, which is potentially quite valuable in young children.”
Fifty-five children in Western Australia, 5 years and younger, have been identified with possible convulsions after receiving the shot and a further 196 had less serious reactions such as fever, vomiting and inflammation at the injection site, Western Australia’s health department said. Between 20,000 and 30,000 children in the age group have been vaccinated so far this year, the department estimates.
A study of Fluvax among 298 children aged between 6 months and 8 years published in the journal Influenza and Other Respiratory Viruses last year found that 3.4 percent suffered severe fever, and one child had convulsions.
“The risk of whether or not children have a convulsion with a fever is usually age-related,” said Jodie McVernon, a senior research fellow at the University of Melbourne who participated in the research. “The younger you are, the more likely you are to have a fit with a fever, and it’s something that you grow out of.”
CSL, based in Melbourne, has fallen 9.6 percent on the Australian stock exchange since April 23, when the reactions were first reported and the company’s larger competitor, Baxter International Inc., cut its profit forecast. The stock rose 1.8 percent to close at A$33.08, compared with a 1.2 percent decline in the benchmark S&P/ASX 200 Index. “The vast majority of the share price reaction reflects the concerns raised by Baxter,” said David Low, a health-care analyst at Deutsche Bank AG in Sydney. “The domestic flu business is relatively small. I would only be concerned if there are implications for the Northern Hemisphere flu market, which we think are unlikely.”
Fluvax is the first seasonal influenza vaccine to contain the H1N1 strain that sparked last year’s global flu pandemic. It also includes type-B influenza and a new variant of the H3N2 strain that the World Health Organization said is circulating sporadically in Australia, the U.S., China and at least 11 other nations.
CSL, the only maker of flu vaccine in the Southern Hemisphere, is investigating the cases, Jo Lynch, an external spokeswoman for CSL, said by phone. Initial evidence suggests the reactions aren’t related to a single batch, she said.
Almost 65,000 children aged 5 and younger in Western Australia received free flu vaccinations made by CSL and Sanofi- Aventis SA in 2008 as part of a trial that reduced hospitalizations by 88 percent, the state’s health department said in a statement last year. Parents in other states and territories have to pay for the shots.
“There are many more children who receive flu vaccine in W.A. than elsewhere,” McVernon said. “If there are going to be events like this, it’s going to be seen there first just because there are more children getting vaccine.”
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