Last Updated

21 Nov 2002

Source: Akron Plains Dealer (Ohio). November 21, 2002.

Hospital launches study of smallpox vaccine that's safe for AIDS patients

Associated Press

CLEVELAND - Researchers at University Hospitals are set to begin testing a new smallpox vaccine in a study designed to measure the side effects and immune response in people with AIDS.

If results are favorable, millions of immune-compromised individuals could be vaccinated against smallpox.

The existing vaccine, called Dryvax, is not recommended for people with weak immune systems - including diabetics, transplant recipients, elderly people, small children and HIV-positive individuals - because they are more susceptible to the vaccine's dangerous side effects.

Dr. Hernan Valdez, an assistant professor of medicine at Case Western Reserve University and part of the AIDS Clinical Trials Unit at University Hospitals, said five other U.S. hospitals are participating in the study, which will enroll about 88 people.

The study will test the safety and effectiveness of the modified vaccinia Ankara vaccine, called MVA, for short.

The Food and Drug Administration must approve the protocol before the study can begin, a process that could take up to 30 days, said Dr. Lawrence Fox, medical officer for the HIV Research Branch of the National Institute for AIDS and Infectious Diseases. The NIAID, a federal agency, is sponsoring the study.

Though MVA has never undergone widespread testing in the United States, Valdez said a recent German study of HIV-positive individuals of the vaccine produced only minor side effects. The primary side effect was soreness at the vaccination site.

In contrast, Dryvax, which is made from cow guts, may cause severe skin problems, blindness and brain inflammation. For every million people vaccinated, 15 develop life-threatening problems and at least one dies.

However, although MVA is considered safer than Dryvax, scientists aren't sure that it alone can prevent smallpox.

"We hypothesize that those immune responses will be sufficient to reduce infection against smallpox," Fox said. "But unless there is actually a smallpox outbreak, we'll never know."

Dryvax is currently the only smallpox vaccine available in the United States. The vaccine is credited with eradicating smallpox throughout the world by protecting people from infection.

The U.S. government discontinued universal Dryvax vaccinations in 1972 because it became apparent that the vaccine was more of a health threat than the disease itself.

The World Health Organization declared smallpox eradicated in 1980.