This in from Reuters recently.
Tai chi boosts elderly immune system against shingles
Fri Mar 23, 2007 3:51PM EDT
NEW YORK (Reuters Life!) - A slow-movement form of exercise known as tai chi can strengthen the immune system in the elderly and boost the potency of a vaccine against the virus that causes shingles, researchers said on Friday.

They found that tai chi, a westernized version of the 2,000-year-old Chinese martial art, improved the immune system in the elderly against the painful, blistery rash that is caused by the same virus as chickenpox.

When tai chi, which involves a series of movements, was combined with a vaccine against shingles the immunity in the patients reached levels seen in younger people.

"These are exciting findings, because the positive results of this study also have implications for other infectious diseases like influenza and pneumonia," said Professor Michael Irwin, lead author of the study from the University of California, Los Angeles (UCLA).

"Since older adults often show blunted protective responses to vaccines, this study suggests that tai chi is an approach that might complement and augment the efficacy of other vaccines, such as influenza," he added in a statement.

Shingles is caused by the varicella zoster virus. People who had chicken pox as children are susceptible to shingles. The virus can remain dormant in the body and as the immune system weakens with age it may cause shingles, which can be very painful and usually lasts three to five weeks.

About one third of adults over 60 years old will suffer from shingles, according to the researchers.

In a study published in the April issue of the Journal of the American Geriatrics Society, Irwin and his team compared 112 elderly people who took tai chi classes three times a week for 16 weeks and others who attended health education classes.

Both groups were also immunized with a dose of a shingles vaccine. At the end of the 25-week study the level of immunity of people who did tai chi was two times higher than the other group. They also functioned better physically and mentally.
It's an expanded study of earlier work done by Prof. Michael Irwin. Here's an older report:

Tai Chi for the Shingles
Chinese meditation and exercise strengthen the body's immune system and are particularly beneficial for elderly adults.
By:William Whitney

Meditation and exercise are good for you: both practices improve flexibility, reduce stress and keep you in shape. As it turns out, these habits may help strengthen your immune system as well. A recent study of elderly adults who practiced Tai Chi finds the martial art increased immunity to shingles, a painful rash related to chicken pox.

Chickenpox attacks are caused by the varicella zoster virus. Children who get the disease generally recover quickly, but the body doesn't completely get rid of the virus—it remains dormant in the nerve tissue of the body. With age, the weakening immune system may allow the virus to re-emerge as shingles: a painful rash that causes pain lasting for months of years.

To find out if the virus might be held in check through a regular program of meditative exercise, Michael Irwin a professor at the UCLA Neuropsychiatric Institute conducted a comparative study. He asked half of a group of 36 elderly adults to follow a 15-week program of Tai Chi Chih, a westernized version of the 3,000-year-old martial art Tai Chi Chuan. A week after the program was complete, Irwin measured the subjects' immune response to the shingles virus. As compared to the group who hadn't been exercising, this half of the study showed an average 50 percent increase in the immune cells. This helps control shingles and other diseases as well.

The Tai Chi students' overall health improved. Adults who suffered from physical impairments, such as a limp, showed the greatest improvement.

Although the study focused only on the shingles virus, Irwin expects similar results for other diseases. "I would expect to see changes across a whole host of responses for a whole host of various viral infections," he says.

Tai Chi Chih is a standardized series of 20 movements developed for older adults. It combines meditation, relaxation and components of aerobic exercise. It is easy to learn, and can be taught from a manual.

The report appeared in the September issue of Psychosomatic Medicine. Irwin plans a follow-up study to examine the duration of the increased immune response, and to investigate how Tai Chi actually improves health.