* Vaccine protected ferrets against H1N1
* Even low doses of vaccine worked
(Corrects last paragraph to show the U.S. will produce 20
million doses of vaccine a week after mid-October, not per
By Maggie Fox, Health and Science Editor
WASHINGTON, Aug 18 A new kind of influenza
vaccine works against the new swine flu virus in animals,
Novavax, Inc. (NVAX.O) reported on Tuesday.
The company said it made the vaccine, which uses so-called
virus-like particles, in fewer than four weeks after the U.S.
Centers for Disease Control and Prevention released the genetic
sequence of the H1N1 swine flu virus, which is now causing a
These virus-like particles are a mock version of the virus,
made using the genetic sequence.
Novavax said the vaccine protected ferrets against the new
pandemic strain. Ferrets are the closest animal to humans when
it comes to being infected with influenza.
"The ferrets received a 3.75, 7.5, or 15 microgram dose of
the 2009 H1N1 virus-like particle vaccine or a placebo and were
boosted with a second dose after three weeks," the company said
in a statement.
Researchers at the CDC infected the animals with H1N1 taken
from a California patient. "By day five after challenge,
immunized ferrets at all vaccine dose levels had cleared the
H1N1 virus and showed no sign of disease," the company said.
"In contrast, control animals that received no vaccine
displayed lethargy, elevated body temperatures and shed
infectious virus for up to six days post-infection," it added.
Novavax would have to get U.S. Food and Drug Administration
approval before it could test its new vaccine in people. Years
of testing are likely to be required before such a new
formulation of a vaccine could be widely used in people.
OLD FASHIONED TECHNOLOGY
Clinical trials of H1N1 vaccine made the old-fashioned way,
with chicken eggs, are under way, and five companies are making
it for the U.S. market -- AstraZeneca's (AZN.L) MedImmune unit,
CSL, GlaxoSmithKline Plc (GSK.L), Novartis AG NOVN.VX and
Sanofi-Aventis SA (SASY.PA).
Novavax Inc., based in Rockville, Maryland, has been using
its new technology to develop a vaccine against H5N1 avian
Most influenza vaccines use either a weakened but live flu
virus or a killed virus to stimulate the immune system. They
must be reformulated every year to match the constantly
mutating flu strains and take five to six months to make using
specially grown live chicken eggs.
Novavax grows the vaccine in lab dishes of caterpillar
cells in a process the company says is quicker. It uses a decoy
of the virus called a virus-like particle. The body recognizes
the particle as a virus but it cannot infect cells and
The World Health Organization declared H1N1 a pandemic in
June, and the virus has spread to about 180 countries. World
health officials have said people should receive the two-dose
swine flu vaccination as well as the single-dose seasonal flu
vaccination this year.
In July, U.S. advisers said about half the U.S. population,
or 160 million people, should get vaccinated against the new
pandemic influenza strain, with pregnant women and healthcare
workers at the front of the line.
But the U.S. Health and Human Services Department has said
it can only get about 45 million doses of flu vaccine by
mid-October, and about 20 million doses a week after that.
(Editing by Philip Barbara)