Smallpox vaccine 'stretching' study under way in U.S.

Tuesday, November 06, 2001

By Christopher Snowbeck, Post-Gazette Staff Writer

Researchers this month started vaccinating a small segment of the population against smallpox as part of a study to see whether the government can stretch its current supply of 15 million doses.

The new study is a continuation of research completed last year that featured two key conclusions: the stockpiled vaccine had maintained its potency since production stopped in 1983; and the majority of people who received only one-tenth the regular vaccine dose developed signs of immunity.

The immune response was not so robust that it would be sufficient for a large population, but the new study is looking at whether a diluted vaccine combined with an alternative vaccination schedule would do the job. The study, which will last more than two months, is enrolling 684 patients in St. Louis, Houston, Baltimore and Rochester, N.Y.

It isn't the first time doctors have had to stretch vaccine supplies when confronting the threat of smallpox.

In 1962, the late Dr. Robert A. Hingson, a Pittsburgh anesthesiologist, was leading a medical team to Liberia to do mass immunizations when a smallpox case passed through New York City. It was the last case of smallpox on the continent and it prompted New York's governor to requisition about two-thirds of Hingson's vaccine supply.

Hingson, who founded the North Side humanitarian relief organization Brother's Brother Foundation, decided to continue with the trip, nonetheless. During the ocean crossing, he performed experiments on volunteer sailors that proved a jet injector could effectively immunize a person with one-hundredth the normal amount of vaccine. The injector, nicknamed the "peace gun," used high pressure rather than needles to inject the medicine.

"He did trial studies on the boat crew while going over," recalled Luke Hingson, the doctor's son and the current director of the foundation. "This was real easy for him, because his brother was the commander of the ship, but in today's world, you wouldn't do this stuff.

"Nobody died, no one got hurt and the end result was that he had proof when he got to Africa that it worked."

Dr. Sharon Frey, the infectious diseases researcher at St. Louis University leading the new study, said researchers are using the standard double-needle injection method to vaccinate people. But, she added, the jet injector would be a viable option.

In any case, stretching existing supplies is a stopgap measure: The federal government announced last month that it would stockpile 300 million doses of smallpox vaccine for use in the event of an outbreak.

http://www.post-gazette.com/healthscience/20011106hvaccine.asp

-- Martin Thompson (mthom1927@aol.com), November 06, 2001