ADVISORY/On April 17, 2000, a Preliminary Discovery in the Ongoing Search for an HIV Preventive Will Be Announced by Samuel Baron, M.D.

Health/Medical Writers

ADVISORY...for Monday (April 17)

--(BW HealthWire)

WHO:  Samuel Baron, M.D., professor of microbiology and immunology,
      professor of internal medicine, University of Texas Medical
      Branch in Galveston

WHAT: The announcement of new insights into how human immunodeficiency
      virus (HIV) is transmitted, and test tube studies of over-the-
      counter products that will now be tested clinically by one of
      the producing companies to determine whether they will help
      prevent new HIV infections in people

WHEN: April 17
      11:45 a.m.

WHERE: 13th International Conference on Anti-Viral Research
       Renaissance Harborplace Hotel
       Baltimore, Md.

Dr. Samuel Baron will present preliminary test tube studies of the potential of three personal lubricant products, sold over the counter, that may prevent transmission of HIV by killing on contact the white blood cells that the literature indicates are the disease's primary transmitters in seminal fluid.

We urge you to give your serious attention to this forthcoming announcement. The products Dr. Baron refers to are FDA Class 1 Medical Devices. Dr. Baron will provide this information when he presents his paper, and we can provide details immediately after the conference. If you would like to speak with Dr. Baron or with someone involved with the products he identified, please contact this office.

At least 30 million people around the world carry the HIV virus, with 5.8 million transmissions per year. Most new cases are sexual transmissions and, therefore, potentially preventable. According to Dr. Baron, although barrier preventives such as condoms are recommended, commonplace and effective, millions of people do not use them, whether as a result of personal preferences, lack of education, cultural biases or religious proscriptions. The high annual transmission rate suggests that condoms, recommended as the most effective preventive, are not being used sufficiently to curtail new infections.

In 1999, Dr. Baron and colleagues began research to understand why HIV is rarely transmitted via oral contact (kissing, dental treatments, biting or aerosolization -- sneezing, coughing, etc.) even when blood or exudate is present. It was already known that very little free virus is present in the semen and other fluids of HIV carriers; the actual transmitting agent is more likely the HIV-infected leukocyte.

Saliva of infected individuals usually contains only noninfectious components of HIV, indicating that some element was breaking down the virus. Dr. Baron's research, performed in vitro (in test tubes rather than on human participants), revealed that saliva's natural hypotonicity (low salt) rapidly disrupted 90% or more of the HIV-infected blood mononuclear leukocytes, with a 10,000-fold or greater inhibition of the multiplication of HIV and surrogate viruses.

"Infected leukocytes are fragile," noted Dr. Baron. "When we found that saliva destroyed them, we began looking for other substances that would work as effectively at the vulnerable vaginal and rectal sites. Ideally, we hoped to locate something familiar and easy to use, usable by women as well as men, safe, inexpensive, and readily available to the U.S. and Western markets, and also in underdeveloped countries.

"Because HIV is, in the majority of cases, sexually transmitted, we began our search for products used for sexual purposes that are sold over the counter. In this area we studied preparations with the potential to prevent disease transmission by inactivating HIV-infected white blood cells."

Dr. Baron stressed that any positive findings, in vitro, would have to be studied in human clinical trials to establish their effectiveness in stopping transmission of the AIDS virus and said that people should not rely on them to prevent transmission until human clinical trials were undertaken to establish their effectiveness in stopping transmission of the AIDS virus among people.