ETSU physicians study vaccine effectiveness in the immunosuppressed

Drs. Jonathan Moorman (standing) and Dr. Zhi Qiang Yao (seated)

JOHNSON CITY (December 18, 2014) – For individuals with chronic viral infections such as hepatitis C or HIV, protecting their already compromised immune systems from other diseases can mean the difference between life and death.

That’s why doctors who treat these patients find it so frustrating that vaccines to prevent additional diseases, like influenza or pneumonia, for example, are significantly less effective in individuals with chronic viral infections.

“They most need that protection, and yet they are the worst responders to vaccines,” said Dr. Jonathan Moorman, a professor of medicine at East Tennessee State University’s Quillen College of Medicine and section chief for infectious diseases at the Quillen Veterans Affairs Medical Center. “As clinicians, it is a nightmare. They just don’t respond to them.”

Dr. Zhi Qiang Yao, also a professor of medicine at ETSU and director of the Hepatology Program at the VA, worked with Moorman to garner $1.825 million in federal grant funding recently to further study the issue, one that they have been working on together for years.

“This particular proposal will study how chronic viral infections can skew the immune system, particularly T-cells,” Yao said. “With these patients, their T-cells appear to be aged. We want to know what is driving that aging.”

If they can figure that out, Moorman noted, they are one step closer to finding a solution to the problem.

“We suspect there’s a common mechanism, perhaps a common pathway in the body, that is driving it,” Moorman said. “These mechanisms are likely already in place and they are probably there for a reason. We think the virus is just exploiting them.”

While Moorman and Yao are focusing on aging T-cells in patients with chronic viral infections, they said similar aging of T-cells often can be seen in elderly individuals, cancer patients, transplant patients and others with immune suppression.

“We suspect it applies to a lot of immunocompromised conditions,” Moorman said. “Almost everything we study in terms of research has a big-picture approach – as in what this means for human disease as a whole.”

Ideally, the physician clinicians hope their research will help lead to the development of a drug to stop the aging of T-cells and ultimately make vaccines more effective in the most vulnerable patients.

The five-year grant was awarded to Yao and Moorman by the National Institutes of Health.
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