Researchers at the University of Kentucky are studying the safety of a new vaccine for smallpox.
The study is part of a national program to develop vaccines that would protect U.S. citizens against a terrorist attack that involved biological agents.
“It’s going to help the United States and the world,” said Dr. Richard Greenberg, who studies infectious diseases and is leading the research at UK.
The study, being conducted at 11 sites in the United States and Mexico, doesn’t involve the smallpox virus, which is highly contagious and was eradicated through vaccination.
Unlike the current vaccine, which leaves a pocklike scar, the new one is injected.
Called Imvamune, it contains a non-replicating version of the vaccinia virus, which scientists believe will make it safer than the current vaccine.
The study is examining how people who have chronic inflammatory skin conditions such as eczema react to the new vaccine.
The current vaccine, which delivers the live virus vaccinia with a series of pricks, can cause serious, even life-threatening conditions in people with atopic dermatitis, as the skin conditions are called.
“The vaccinia that would be given by the pricks could progress instead of go away and basically eat up their skin,” Greenberg said.
The new vaccine contains a version of vaccinia developed in Germany that has less genetic material and has lost its ability to replicate.
Most Americans aren’t vaccinated against smallpox. The last U.S. case of the devastating disease occurred in 1949, and routine vaccinations ended in the United States in 1972.
The last known naturally occurring case of smallpox was in 1977 in Somalia. Since then, smallpox has existed only inside two labs, one in the United States and one in Russia.
Until recently, only researchers who worked with smallpox or similar diseases were vaccinated.
But after Sept. 11, 2001, the U.S. government stepped up its vaccination program. Soldiers are now vaccinated for the disease, and the federal government began supporting research to create a new, safer vaccine.
The current vaccine can have serious side effects. It is made with a different virus than smallpox, but the virus is live. The vaccine causes a blister to form at the vaccination site, which fills with pus and eventually forms a scar. If proper care is not taken, the vaccinia virus can spread to other parts of the body and other people.
The Centers for Disease Control and Prevention estimates that for every 1 million people vaccinated, one or 2 may die and others will have serious side effects.
In the study of the new vaccine, healthy volunteers, those with atopic dermatitis, and those with a history of atopic dermatitis will be vaccinated. Their immune reaction will be measured through blood tests, and side effects will be tracked in a journal.
Because smallpox no longer exists naturally, scientists have no way of proving that a vaccine like Imvamune works in humans. They can only measure the immune response.
“It’s a reasonable leap of faith, but it’s a leap of faith,” Greenberg said.
The study is being paid for by Bavarian Nordic, which is developing the vaccine, and the National Institute of Allergy and Infectious Diseases.
It is the second study of Imvamune that Greenberg has worked on. In October, he and others will present the results of an earlier study looking at the safety of Imvamune in people who have HIV, the virus that causes AIDS.