Smallpox research may show need for extra shot

ROCHESTER, N.Y. -- In a hallway at Strong Memorial Hospital, two volunteers in a medical study showed off the results of booster vaccinations they were given for the smallpox vaccinations they had received as children.

"I've got a nice big round thing that itches like crazy," said James Campbell, 67, pointing at the fresh scar on his left shoulder that matches one he got in 1940.

"Me too!" said Janet Martel, mother of two teenagers. "I probably had no immunity left, which surprises me."

About half of all Americans alive today were inoculated for smallpox as children, and most still carry residual protection, though not nearly as strong as in the five to 10 years after the inoculation, said Dr. John Treanor, the study's chief investigator.

The dime-sized blisters, which typically scab over and heal within weeks, indicate the vaccine took, Treanor said. Now, those once-familiar scars could become commonplace again if fears of bioterrorism translate into a mass vaccination campaign.

Smallpox vaccinations began Friday for the military, and medical workers could start getting them in January. The government is not recommending smallpox inoculation for most Americans, but the vaccine is already available for those who volunteer for medical studies.

Seven research sites

At Strong Memorial, the University of Rochester's research hospital, and six other research sites around the country, 927 people are taking part in a study sponsored by the National Institutes of Health. It will determine if diluted smallpox vaccine can boost the immunity of people vaccinated before 1972, when routine inoculation ended in the United States.

Earlier studies on unvaccinated younger adults indicated the limited government stockpile of the 40-year-old smallpox vaccine -- some 15 million doses -- could be diluted five to 10 times and still be effective.

Now researchers want to see if the same holds true in those already vaccinated. The results, to be published in the spring, could differ because previously vaccinated people might need stronger doses.

"They'd be a little immune and may not get quite as vigorous a viral replication as you would see in people who had never been vaccinated," said Treanor, director of the Vaccine and Treatment Evaluation Unit at the University of Rochester Medical Center.

Smallpox once killed hundreds of millions of people. About a third of those infected died, and survivors were often blinded or disfigured. A vaccine was developed in 1796.

The last smallpox case in the world was recorded in Somalia in 1977, and the disease hasn't been seen in the United States for half a century.

Some of the most definitive historical data is provided by a rare outbreak in Liverpool, England, in 1902. The epidemic killed about half the infected adults over 50 who'd never been inoculated and bypassed every vaccinated child. As for adults inoculated as youngsters, "most developed smallpox and about 10 percent of them died," Treanor said.

"The general feeling is vaccine protection lasts for a few years and then it starts to go away bit by bit," he said.

Fear that smallpox could be used as a terrorist weapon has been raised by growing hostilities with Iraq -- believed by U.S. intelligence officials to posses smallpox virus -- and evidence found in Afghanistan that Osama bin Laden was pursuing potential biological weapons.

With all that is going on in the world, "it's not going to be long before people are going to be more fully aware of things like biohazards," said Campbell, a retired philosophy professor.

"I do not know the depths to which the world will go, so I don't think we can take chances. It is sad. Some Chinese say, 'Woe to those who live in interesting times.' We live in interesting times."

Martel, a drug company administrator, thinks the public has become lackadaisical about vaccines, especially younger people unfamiliar with scourges like polio. A big believer in vaccines, she gets a flu shot every year. "If the prevention is out there, why not?" she said.

Another volunteer, Todd Sazenski, 34, said he experienced the normal red, itchy bump. But his wife, who volunteered for a separate study of non-vaccinated adults a year ago, suffered headaches and had swollen lymph nodes for a couple of days.

Some of her fellow participants had grapefruit-sized swellings, rashes and flu-like aches, and one in three was sufficiently ill to miss school or work or have trouble sleeping, Treanor said.

In the current study at Strong Memorial, symptoms have been much milder, he said.

The study is also taking place at Saint Louis University Medical Center, the University of Maryland, Duke University Medical Center, Stanford University, Kaiser Permanente California and the University of California, Los Angeles.