Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, June 10, 1993 TAG: 9306090337
SECTION: NATIONAL/INTERNATIONAL PAGE: A-9 EDITION: METRO
SOURCE: Associated Press
DATELINE: BERLIN LENGTH: Medium
"We're on a relatively rapidly rising curve," said Dani Bolognesi of Duke University, co-chair of the U.S. government's AIDS vaccine working group.
The experimental vaccines "have a very good safety record" and "the extent to which they provoke immune responses . . . is improving rapidly," he said in a report at the Ninth International Conference on AIDS.
The most effective vaccines so far, and the ones likely to be chosen for efficacy trials, are the vaccines made by Genentech and Biocine, a joint venture of Chiron and CIBA-Giegy, Bolognesi said.
The vaccines boost levels of so-called neutralizing antibodies, capable of inactivating the AIDS virus or preventing it from attacking other cells. The vaccines are now triggering antibody levels 10 times higher than those produced by earlier vaccines.
In an 18-month study of 42 volunteers, Dr. James Kahn of the University of California, San Francisco found that the Chiron vaccine produced neutralizing antibodies in all who received it and that the antibodies remained for six months. The vaccine also appeared to produce antibodies not only against the virus it was designed to fight but also against a closely related strain, Kahn reported at the conference.
The progress discussed by Kahn and Bolognesi dealt solely with vaccines intended to protect uninfected people against infection with the human immunodeficiency virus, or HIV, that causes AIDS.
Dr. Jonas Salk, the developer of the polio vaccine, and other researchers are exploring the possibility of using vaccines in people infected with HIV to prevent disease symptoms or reduce their severity.
Salk and his colleagues reported finding slight improvement in some laboratory measures of patients given his vaccine when they were already infected with HIV.
Salk's celebrity commanded attendance by a large crowd of scientists and reporters, but experts said his findings were too preliminary to be evaluated.
"I don't think it's one of the highest priority things," said Myron Essex of Harvard University. Asked whether the work would have attracted any attention if it had not been done by Salk, Essex said, "Probably not."
Researchers from Genentech and Biocine reported that they could further boost the effectiveness of their vaccines by combining them with general immune-system boosters called adjuvants.
Bolognesi said it is impossible to say whether a vaccine will be available by the end of the 1990s. Walter Dowdle of the U.S. Centers for Disease Control and Prevention noted that problems would remain even if a safe, inexpensive vaccine becomes available.
People may not choose to have the vaccine, either because they are afraid of it or believe they are not at risk, Dowdle said. "Many years would be required to reduce current prevalence rates," he said. "There are no short cuts."
Nevertheless, he said, "a safe and effective HIV vaccine is critical for the control of this epidemic."
by CNB