October 29, 2004

Researchers probe alternate vaccine to ward off smallpox

Featured Image

Kathryn Edwards, M.D., administers the smallpox vaccine to Kyle Arneson.
photo by Dana Johnson

Researchers probe alternate vaccine to ward off smallpox

Vanderbilt University Medical Center Infectious Diseases researchers will launch a smallpox vaccine trial testing a new vaccine that has historically been shown to have fewer side effects than the current smallpox vaccine currently licensed for use in the United States.

It marks the third time that smallpox vaccine studies have been conducted at VUMC. Previous studies focused on the effectiveness of dressings; whether decades-old vaccine was still viable, even when diluted, and to determine a dilution of the vaccine that still remains effective.

VUMC is one of four clinical sites in the nation participating in this trial, which includes the University of Kentucky School of Medicine, St. Louis University Health Sciences Center and Stanford University.

The new vaccine candidate, LC16m8, has been used safely since the 1980s in Japan.

"We know from evaluation of LC16m8 during its development in Japan that the vaccine candidate has a strong track record of safety," said Tom Talbot, M.D., assistant professor of Medicine in the Division of Infectious Diseases. "With the start of this study in the United States, we look forward to gathering additional data about the vaccine's safety and immunogenicity. Together with what we've learned from the Japanese experience, we expect the results of this study to advance the understanding of attenuated smallpox vaccines and help the U.S. government and other potential purchasers determine the most appropriate attenuated smallpox vaccine for use in the general population."

The trial is seeking volunteers ages 18 to 33, who have never been vaccinated for smallpox, to participate in a phase I/II clinical trial to evaluate the safety and immune response of its attenuated smallpox vaccine candidate, LC16m8. Participants in the trial can receive up to $625 compensation for volunteering.

The trial includes 10 clinic visits, over a period of 52 weeks. Candidates must be healthy, and have not served in the military.

VUMC will be seeking approximately 45 volunteers, who will be randomized 4:1, with some receiving LC16m8 and others receiving Dryvax(R), the smallpox vaccine currently licensed in the United States. Study volunteers will be screened carefully for safety risk factors prior to enrollment.

The screening process includes a physician's assessment of the volunteer's medical history, a physical exam, and a panel of cardiac and laboratory tests.

All study volunteers will continue to be evaluated for safety in the clinic after vaccination and will return for regular safety assessments throughout the study. No one will be exposed to smallpox as a part of the clinical study.

LC16m8 is produced in cell culture from vaccinia virus that has been attenuated, or modified, to reduce its potential to cause unwanted side effects.

For more information, contact the Smallpox Trials Hotline at (615) 322-2757.