Two-step vaccine may offer ‘universal’ flu jab

* Vaccine protected against strains going back to 1930

* Tests in people underway

* Could open fresh new approach to flu shots

By Maggie Fox, Health and Science Editor

WASHINGTON, July 15 (BestGrowthStock) – A two-step flu vaccine
using DNA to “prime” the immune system and then a traditional
seasonal influenza vaccine may be able to protect against all
strains of the virus — providing a long-sought “universal” flu
vaccine, U.S. researchers said on Thursday.

The team at the National Institute of Allergy and
Infectious Diseases is already testing the new vaccine in
people and says the results of tests in mice, ferrets and
monkeys suggest the industry may finally be able to dump the
cumbersome process of making fresh flu vaccines every year.

“This is the first step, conceptually, towards a good shot
at a universal vaccine,” NIAID Director Dr. Anthony Fauci said
in a telephone interview.

Every year, the influenza strains that are circulating
mutate a little bit and at any given time several very
different strains are infecting people. In some years a new
mutant pops up — such as the new H1N1 swine flu strain that
appeared in March 2009 to spark a pandemic.

Vaccine makers have to change their formulations every year
to match the current strains. To make matters worse, virtually
all flu vaccines are made using decades-old technology based on
chicken eggs that is both slow and prone to contamination.

So the goal is to come up with a universal influenza
vaccine that could protect people from all flu strains for
decades or even for life.

NIAID’s Dr. Gary Nabel said his lab has taken a big step
toward this goal. Their method, described in the journal
Science, starts with a piece of DNA based on the hemagglutinin
protein — a mushroom-shaped structure on the outside of the
virus that gives flu strains the “H” in their names.

The DNA directs the body to make antibodies against a part
of the flu virus that is normally hidden — on the “stem” of
the hemagglutinin protein. This part is conserved, meaning it
does not change from flu strain to flu strain.

OLD AND NEW STRAINS

Vaccinated mice and ferrets produced antibodies that
protected them against flu strains from 1934 through 2007.

“We are excited by these results,” Nabel said. “The
prime-boost approach opens a new door to vaccinations for
influenza that would be similar to vaccination against such
diseases as hepatitis, where we vaccinate early in life and
then boost immunity through occasional, additional inoculations
in adulthood.”

The vaccine, which uses DNA from Netherlands-based Crucell
NV (CRCL.AS: ), “looks pretty safe,” Fauci said. “They are
already well into, at least a full year into, a Phase 1
trial.”

Such trials are meant to see if a new drug or vaccine is
safe in people. A larger, Phase 2 trial could start next year,
Fauci said.

Seasonal influenza kills 250,000 to 500,000 people a year
globally, including 36,000 in the United States. Pandemics
often kill more and while H1N1 has not been especially deadly,
it has killed far more children, young adults and pregnant
women than seasonal flu usually does.

The experimental vaccine protected animals against H5N1
bird flu, as well. While avian influenza only rarely infects
people, it has killed 296 of the 500 sickened by it since
2003.

Flu experts fear H5N1 could mutate and cause a pandemic far
worse than swine flu and, using current vaccine technology, it
will take months to formulate a good vaccine against it. Swine
flu made its spread global within six weeks.

Dozens of companies make influenza vaccines, including
Sanofi Aventis (SASY.PA: ), GlaxoSmithKline (GSK.L: ), Novartis
(NOVN.VX: ), AstraZeneca (AZN.N: ) and CSL (CSL.AX: ).
(Editing by Eric Walsh)

Two-step vaccine may offer ‘universal’ flu jab