Researchers aim to stretch limited supply of flu vaccine

September 1, 2009 By Julia Prodis Sulek

Worried there won't be enough of the swine flu vaccine? Stanford University researchers are beginning clinical trials to determine if vaccines for the swine flu virus, also known as H1N1, could be stretched by lowering the dosage and coupling it with a booster.

If successful, it could mean that doctors would give people one swine flu shot instead of the anticipated two doses spread three weeks apart.

"Going to the public with a two-vaccination regimen is going to be complicated, there's no doubt," said Dr. Cornelia Dekker, who is running the clinical trial at Stanford. If the Stanford study determines only one dose is needed, "it would be a great source of comfort" to health professionals putting vaccination programs together.

The government had hoped to have 120 million doses of the H1N1 vaccine on hand by Oct. 15. Because of delays in the manufacturing process, however, only 45 million doses are expected to be available by then.

The Stanford study results are unlikely to translate into a new booster-infused vaccine before the end of the year. Boosters are added to the vaccine to strengthen the immune system and make the vaccine more potent; such methods have been used with previous flu vaccines. If the lower dosages are successful, the supply could be extended in late winter.

Because most people's immune systems have never been exposed to the virus, a vaccine is critical to deter its spread.

To limit the spread of swine flu before the vaccine is ready, health officials continue to urge people to wash their hands frequently, stay home if ill and not return to school or work until 24 hours after symptoms disappear.

The public is also encouraged to be vaccinated for the seasonal flu now, several weeks earlier than when seasonal flu shots are normally available, so health professionals won't be overwhelmed by requests for both seasonal and swine flu vaccines come mid-October.

Safeway began offering seasonal flu shots Aug. 19, more than a month before the supermarket normally does. And the demand is already as high as it normally is in late September.

Dr. Marty Fenstershieb, public health officer in Santa Clara County, Calif., said there's no harm in getting the seasonal flu vaccine early.

"If people have any concern that getting it early means it won't last, it will last," he said. "Getting it now will last them through the season."

Pregnant women and people with chronic health problems are the most vulnerable to serious complications from swine flu. Most people who have contracted swine flu recover at home with standard fever medication, much like the seasonal flu, Fenstershieb said. The average age of those infected so far with swine flu is about 17, he said. And though that age group might not suffer the most severe flu symptoms, he said, it's important to vaccinate them so they don't spread it to the more vulnerable.

Stanford is recruiting 130 volunteers that it will divide into two groups: those between 18 and 64 and those 65 and older.

"That older age group is a little harder to immunize," Dekker said. The booster, also called an adjuvant, will hopefully result in a better response from the immune systems of older people, she said.

Unlike other clinical trials at Stanford that take as long as six weeks to enroll volunteers, this study in on a fast track with enrollment ending within a week.

"Our current plan is to start our screening the week after Labor Day," Dekker said. "The following week, our goal is to be immunizing" by Sept. 14.
___

(c) 2009, San Jose Mercury News (San Jose, Calif.).
Visit MercuryNews.com, the World Wide Web site of the Mercury News, at http://www.mercurynews.com
Distributed by McClatchy-Tribune Information Services.