A strain of bird flu that
scientists thought could not infect people has shown up in a Taiwanese woman, a
nasty surprise that shows scientists must do more to spot worrisome flu strains
before they ignite a global outbreak, doctors say.
On a more hopeful front, a
company reported encouraging results from its first human tests of
a possible vaccine against a different type of bird flu that has been spreading
through Asia since first appearing in China last spring that is feared to have
The woman, 20, was
hospitalised in May with a lung infection. After being treated with Tamiflu and
antibiotics, she was released. One of her throat swabs was sent to the Taiwan
Centres for Disease Control.
No early warning signs
Experts there identified it as the H6N1 bird
flu, widely circulating in chickens on the island.
The patient, who was not
identified, worked in a deli and had no known connection to live birds.
Investigators couldn't figure out how she was infected. But they noted several
of her close family and friends also developed flu-like symptoms after spending
time with her, though none tested positive for H6N1.
The research was published
online in the journal Lancet Respiratory Medicine.
Since the H5N1 bird flu
strain first broke out in southern China in 1996, public health officials have
been nervously monitoring its progress. It has so far killed more than 600
people, mostly in Asia.
Several other bird flu
strains, including H7N9, which was first identified in China in April, have
also caused concern but none has so far mutated into a form able to spread
easily among people.
"The question again is
what it would take for these viruses to evolve into a pandemic strain?"
wrote Marion Koopmans, a virologist at the National Institute for Public Health
and the Environment in the Netherlands, in a commentary accompanying the new
She said it was worrying
that scientists had no early warning signals that such new bird flu’s could be
a problem until humans fell ill.
Scientists often monitor birds to see which
viruses are killing them, in an attempt to guess which flu strains might be
troublesome for humans but neither H6N1 nor H7N9 make birds very sick.
Koopmans called for
increased surveillance of animal flu viruses and more research into predicting
which viruses might cause a global crisis.
"We can surely do
better than to have human beings as sentinels," she wrote.
The vaccine news is on the
H7N9 bird flu that has infected at least 137 people and killed at least 45
since last spring.
Scientists from Novavax
Inc., a Gaithersburg, Md., company, say tests on 284 people suggest that after
two shots of the vaccine, most made antibodies at a level that usually confers
"They gave a third of
the usual dose and yet had antibodies in over 80%," said an expert not
connected with the work, Dr Greg Poland of the Mayo Clinic. "This is
encouraging news. We've struggled to make vaccines quickly enough against novel
viruses," he said.
Results were published
online by the New England Journal of Medicine.