|H1N1 flu pandemic could last years|
|By Compiled from Staff and Wire Reports|
|Sunday, 11 October 2009 03:24|
The WHO moved its six-point pandemic alert level to the top rung in June in response to the spread of the new virus widely known as swine flu, which has killed at least 4,500 people, especially in North America.
"At some point in the future, there would be a recognition of the fact that if it's no longer circulating on a sustainable basis in communities. Then you would lower the pandemic level," he said, while stressing: "There is absolutely no indication yet of that happening."
In previous pandemics, Hartl said, it has taken time for worrisome flu strains to become less contagious. The slowdown generally comes from people having some prior exposure to the virus or gaining protection from a vaccine.
"Eventually a pandemic virus becomes more like a seasonal virus and that normally will take something like two to three years," Hartl said. "Once enough people either have been vaccinated or have contracted the virus, then it becomes more difficult to spread. It starts acting like a seasonal flu."
National health authorities conduct regular monitoring of flu viruses and research on the circulating strains is used by pharmaceutical companies who sell seasonal flu shots, which normally contain a mixture of a few viruses.
Several firms now scrambling to develop and sell H1N1 flu shots and at least one other is working on a possible treatment for those who have already been infected. That could yield these companies billions of dollars in government orders. China began the world's first mass vaccination program in late September and Australia and the United States have also launched campaigns targeting children and health workers first.
Hartl said there was no sign yet that the pandemic strain had mutated into a more dangerous or more mild form than the one first identified in Mexico and the United States.
"So far the virus has remained quite homogenous," he said.
In its latest snapshot of the spreading virus, also released on Friday, the WHO said there has been an unusually early start of flu-like illness in the northern hemisphere this autumn.
Influenza viruses thrive in colder climates and normally pack the biggest punch in winter.
Young people at great risk
H1N1 poses a greater danger of severe illness and death for children and young people than seasonal flu, which is particularly dangerous for the elderly.
Only about 20 percent of U.S. children get vaccinated against seasonal flu in a typical year. Some parents, including many at Dodge Park Elementary, are holding back on H1N1 vaccination because of worries about the newness of the vaccine -- concerns that health officials say are unfounded.
The U.S. Centers for Disease Control and Prevention said on Friday that 76 U.S. children have died from H1N1 since April, with widespread swine flu in 37 states.
Most victims had underlying disease but 20 to 30 percent were healthy before they contracted swine flu.
This death toll compares with 46 to 88 pediatric deaths for entire flu seasons over the past three years, the CDC said.