August 22, 2013

Vaccine researchers ready as new flu strain evolves

A worrisome new avian influenza virus, called H7N9, emerged this spring in Eastern China.

A worrisome new avian influenza virus, called H7N9, emerged this spring in Eastern China.

Like the H5N1 avian strain before it, this influenza has a high mortality rate, and hit the radars of pandemic watchers across the globe within weeks of the first outbreak in March.

Kathryn Edwards, M.D., Sarah H. Sell and Cornelius Vanderbilt Professor of Pediatrics and director of the Vanderbilt Vaccine Research Program, is among several Vanderbilt experts watching carefully.

Kathryn Edwards, M.D., and colleagues are closely monitoring the new H7N9 avian influenza virus that emerged this spring in China. (photo by Susan Urmy)

“I think we’re worried about it. There is evidence just in the last couple of weeks that it can infect human cells, and there is one case of human-to-human transmission,” Edwards said.

Edwards, who is known internationally for her work as a vaccinologist, serves as the principal investigator of the team of vaccine research experts quietly warming its engine in case a call comes from federal health officials. Like a version of 9-1-1 for pandemic concerns, Vanderbilt stands ready as one of eight national Vaccine and Treatment Evaluation Units (VTEUs) funded by the National Institutes of Health (NIH), available on short notice to work to test a vaccine to protect against the world’s next pandemic.

“The implications are if there were to be a need for quick vaccine development, it is very likely we would be called upon to work on that,” Edwards said.

Edwards says the Vanderbilt VTEU can respond with historic speed.

When the H1N1 pandemic began in 2009, the VTEU had IRB approval and hundreds of registered study participants rolling up their sleeves at Vanderbilt to test the vaccine within weeks.

“That’s pretty amazing when you consider 20 years ago we wouldn’t even have had the surveillance or ability to identify the strain at all,” she said.

The type, amount and speed of information gathering have all increased since the H1N1 pandemic.

The NIH recently funded Edwards, co-investigator Andrew Link, Ph.D., associate professor of Pathology, Microbiology and Immunology, and colleague Leigh Howard, M.D., MPH, to use a “systems-biology” approach to examine human immune responses to H5N1 vaccines.

The same sort of frame-by-frame snapshot of response to an H7N9 vaccine could quickly tell scientists how they might need to modify the vaccine.

In addition, James Crowe Jr., an international leader in the study of influenza pandemic antibody responses, directs the Vanderbilt Vaccine Center (VVC), which specializes in quickly analyzing the blood of both influenza patients and vaccine recipients.

His evidence is used to inform vaccine development and to create potential treatments by finding and cloning the most powerful virus-fighting antibodies.

None of this technology is needed quite yet. While the Centers for Disease Control and Prevention (CDC) issued provider alerts to watch for flu-like illness in recent travelers to China, no H7N9 cases have been reported outside of Asia at this point.

To date, there have been more than 130 cases of illness and 44 deaths, signaling a 20 percent mortality rate.

A single confirmed case of human-to-human transmission occurred in July when a Chinese woman caught the virus while caring for her ill father. By August, both had died.

That recent development is alarming, but H7N9 is still considered by the CDC to be only sporadically infecting humans, most via poultry exposure, with no sustained transmission in the community.