- The Washington Times - Sunday, December 18, 2005


As many as 30 volunteers will participate in a bold experiment in an isolation ward of a Baltimore hospital: A vaccine made with a live version of the H5N1 bird-flu strain will be sprayed into their noses.

First, scientists are dripping that vaccine into the tiny nostrils of mice. It doesn’t appear harmful — researchers have weakened and genetically altered the virus so that no one should get sick or spread germs.

This is essentially FluMist for bird flu, and the hope is that in the event of a flu pandemic, immunizing people through their noses could provide faster, more effective protection than the vaccine that the nation now is struggling to produce.

If it works, this new vaccine frontier may not just protect against H5N1, which is considered today’s top health threat. It offers the potential for rapid, off-the-shelf protection against whatever novel variation of the constantly evolving influenza virus shows up next — through a library of live-virus nasal sprays that the National Institutes of Health (NIH) plans to freeze.

“It’s high-risk, high-reward” research, said Dr. Brian Murphy, who heads the NIH laboratory where Dr. Kanta Subbarao is brewing the nasal sprays.

“It might fail, but if it’s successful, it might prevent hundreds of thousands of cases” of the next killer flu, Dr. Murphy said.

When people catch the flu, they usually get H1 or H3 flu strains, which their bodies can recognize because variations have circulated among humans for decades.

Occasionally, genetically unique strains emerge. Until 1997, H5 strains had never been seen outside of birds. But since 2003, a particularly strong H5N1 strain has infected more than 130 people in Asia, killing at least 70.

Researchers hope to create at least one live-virus nasal spray for each “H” subtype, a project costing about $16 million of the NIH’s annual $67 million budget for flu-vaccine research.

First on Dr. Subbarao’s list were the riskiest known bird flus: H5N1, with human tests planned for April, and H9N2, which recently underwent the first round of human testing in an isolation ward at Johns Hopkins Bayview Medical Center.

In a high-security section of the lab, Dr. Subbarao dons a biohazard suit and exposes vaccinated mice to various bird-flu strains.

Then it’s time for human testing — in a hospital isolation ward just in case the weakened virus could infect someone.

Hopkins researchers gave the first of Dr. Subbarao’s vaccine samples — the H9N2 spray — to 30 volunteers last summer. To be sure they couldn’t spread the virus by coughing or sneezing, the volunteers underwent daily tests of their noses and throats.

The vaccine appeared safe. Scientists now are analyzing whether it also spurred production of flu-fighting antibodies, a sign that people would be protected if they encountered the H9N2 strain. Dr. Subbarao expects results by February.

In April, pending final Food and Drug Administration permission, Dr. Subbarao will put an H5N1 spray to a similar test.



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