US restricts 1918 flu virus samples

By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) – The U.S. Centers for Disease Control
and Prevention restricted access on Thursday to samples of the
1918 pandemic flu virus taken from the frozen bodies and lung
samples of victims, a standard precaution for such a dangerous
virus.

Researchers who want to work with the virus, which killed
anywhere between 20 million and 100 million people, depending
on the estimate, will have to register with the CDC and account
for their samples.

“We’ve learned why this virus was so deadly and we know
it’s easily transmitted from person to person,” CDC Director
Dr. Julie Gerberding said in a statement.

“But there is a lot we don’t know, so it’s only logical
that we take immediate steps to regulate this virus as a select
agent as an added way to protect the public.”

Select agents are considered potentially dangerous and are
controlled.

The CDC lists 41 other organisms or toxins as select agents
under the Public Health Security and Bioterrorism Preparedness
and Response Act of 2002. They include Ebola virus, smallpox
virus, the botulinum toxin and plague bacteria.

Earlier this month, researchers published a study in which
they reconstructed the 1918 influenza virus, which was
especially deadly and which swept the world at the end of World
War One.

“The virus was reconstructed to aid public health officials
in preparing for the possibility of another pandemic of
influenza. It will also be helpful to biomedical scientists as
they seek to understand what made the virus so harmful and to
develop better antiviral drugs and influenza vaccines,” the CDC
said in a statement.

Researchers wishing to study the 1918 virus can ask the CDC
for samples. Gerberding said the CDC will send them to
legitimate researchers who agree to the restrictions.

The researchers who reconstructed the 1918 flu virus
studied mutations in the genes, to see why it became so deadly.

They compared it with the H5N1 avian influenza virus now
sweeping through poultry in many Asian countries and into
European countries including Russia and Romania.

Experts fear H5N1, which does not now easily infect people
but which has killed more than 60, will mutate just enough to
become a pandemic strain, passing easily among people and
killing millions.

They found the 1918 flu virus appeared to also have passed
directly from being a bird flu virus to being one that infected
people, based on its genetic structure.