Last Updated

22 Jun 2003

Source: Wall Street Journal, February 6, 2002.

HEALTH

Study Suggests Smallpox Vaccine Could Be Stretched With Dilution

By MARILYN CHASE, Staff Reporter of THE WALL STREET JOURNAL

Early observations from a study on the feasibility of diluting smallpox vaccine indicate the U.S. can stretch its existing stockpile in the event of a bioterror attack, senior government officials said.

The country has only 15 million doses of the vaccine on hand. Last October, the National Institutes of Health launched a study with more than 600 volunteers comparing their responses to the vaccine at full strength, 1/5-strength and 1/10-strength. Early results of the study bolster hopes of expanding supplies to cover at least 75 million people.

"Everybody's getting a take," said D.A. Henderson, director of the office of public health preparedness of the Department of Health and Human Services. A "take," or sore at the injection site, is an early sign that the vaccine is prompting a good immune response.

"It's going very well," said Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, the unit of the National Institutes of Health that is sponsoring the study. He declined to discuss specifics. "I can't talk about the details," he said. "The data are being analyzed right now and peer-reviewed for publication." Dr. Fauci said he hopes the study will be published late this month or in early March.

Meanwhile, the government is moving ahead to build up the stockpiles. It has contracts totaling $850 million with Acambis PLC, a British firm, and Baxter International Inc., Deerfield, Ill., to manufacture about 200 million new vaccine doses to supplement the old stockpile and cover the entire U.S. population if need be. The newly manufactured vaccine is forecast to be available by year end.

The U.S. discontinued routine smallpox vaccination three decades ago because the risk of side effects outweighed the risk of disease. Smallpox was eradicated in 1980. Made from a live lab virus strain called vaccinia, the smallpox vaccine can cause adverse reactions, including death in three cases out of every million. For this reason, the vaccine isn't recommended for people with weakened immunity, including those with HIV or hepatitis, or who are undergoing cancer chemotherapy.

Another goal of the study was to test the drug cidofovir as a treatment for vaccine side effects. Made by Gilead Sciences Inc., Foster City, Calif., cidofovir is currently approved for an AIDS-related eye condition. But Dr. Henderson suggested that cidofovir's role remains unknown because the study is too small to see many side effects. "My understanding is we haven't had complications in the dilution study," he said.