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STD Quarterly: The war gears up against HIV: Scientists and providers seek enhanced prevention
Rapid tests speed detection — research advances on vaccine trials
When it comes to the battle against HIV, it’s time to redouble your efforts at reducing the number of new HIV infections. Why? Reports show an increase of newly diagnosed infections during 1999-2001, which reverses a several-year decline.1
Since the early 1990s, 40,000 new HIV infections have occurred each year in the United States, according to the Atlanta-based Centers for Disease Control and Prevention (CDC).2 However, during 1999-2001, the number of persons with newly diagnosed HIV infection increased 14% among men having sex with men, and 10% among heterosexuals, in the 25 states with HIV reporting.1 The number of persons in the United States living with HIV also continues to rise; the CDC estimates that of some 850,000-950,000 persons living with HIV, about 25% are unaware of their serostatus.
The CDC now is implementing a four-pronged initiative, aimed at:
While progress has been made on the global epidemic, prevention efforts in the United States have stalled, says Julie Gerberding, MD, MPH, CDC director.
"We are not making the kinds of ongoing progress in reducing new cases that we would expect to be able to achieve, given some of the recent advances in testing technology," she stated in announcing the new initiative.
New tests move forward
Public health officials agree that it is time to break down the barriers when it comes to HIV testing. Many HIV-infected persons do not get tested until late in their infection, and many persons who are tested do not return to learn their test results, reports the CDC.2 In 2000, of an estimated 2 million CDC-funded tests for HIV, approximately 18,000 tests represented new HIV diagnoses; 31% with positive tests for HIV did not return to learn their test results, CDC figures show.2
Clinicians now have a selection of rapid HIV testing options in diagnosing new infections. The Food and Drug Administration (FDA) gave approval in November 2002 to the OraQuick Rapid HIV-1 Antibody Test (OraSure Technologies, Bethlehem, PA) and issued clearance in April 2003 for the Reveal Rapid HIV-1 Antibody Test, manufactured by MedMira of Halifax, Nova Scotia. (Contraceptive Technology Update reported on the OraQuick approval in the February 2003 article, "Rapid HIV testing method approved — prepare now to apply new strategies," p. 13.) The Canadian-based MedMira has entered into an agreement with McGaw Park, IL-based Cardinal Health to market the test in the United States. Research indicates positive performance of the Reveal test.3,4
The OraQuick test provides HIV results in 20 minutes and can be stored at room temperature. The Reveal test offers HIV results in three minutes and also can be stored at room temperature. While rapid tests facilitate receipt of test results, any HIV-positive rapid test results require confirmation by Western Blot or immunofluorescence assays.2
The CDC is committed to working with governmental and community-based organizations to encourage the adoption of HIV testing as a routine part of medical care, says Robert Janssen, MD, director of the CDC’s division of HIV/AIDS prevention.
"One of the major challenges to implementing routine testing is determining how best to remove barriers that can discourage testing," says Janssen. "In addition to promoting the adoption of simplified HIV testing procedures, which will reduce requirements for comprehensive pre-test counseling, CDC will fund demonstration projects that will offer insight as to how to best implement rapid testing inside and outside of the doctor’s office."
Because the rapid HIV test is simple enough to be performed in community settings, the ability to reach those infected with HIV who may not have access to traditional medical settings is greatly expanded, Janssen observes. The CDC anticipates that community-based organizations will begin to play a pivotal role in ensuring newly identified HIV-infected people are linked to appropriate care, treatment, and prevention services, he states.
"Making testing more widely available also will increase opportunities to provide prevention information to both infected individuals and HIV-negative people at risk," states Janssen. "Therefore, while continuing efforts to prevent HIV infection in high-risk negative individuals, CDC will increase emphasis on prevention services for people living with HIV."
Vaccine trial now up
On the prevention front, scientists have launched the first HIV vaccine trial to be conducted simultaneously in the United States and Africa. The Seattle-based HIV Vaccine Trials Network (HVTN), a partnership of investigators, clinical trial sites, and community representatives working with industry and governments for a preventative HIV vaccine, has begun the Phase 1 trial of the HVTN 048 vaccine. The multi-epitope vaccine, also known as EP HIV-1090, is from the San Diego-based pharmaceutical company Epimmune. It will be tested in 42 volunteers in the United States and Botswana. The trial will be conducted at several sites in the Boston area through the Harvard Medical School, in St. Louis through the St. Louis University, and in Gaborone, Botswana, through the Botswana-Harvard Partnership for HIV Research and Education.
"By conducting this trial in two distinct geographies at the same time, we hope to shave precious years off the trial process, therefore expediting the discovery of an HIV vaccine that will save millions of lives in countries around the world, and especially in Africa," says Lawrence Corey, MD, HVTN principal investigator. "The HVTN’s ability to conduct the trial simultaneously in Africa and the U.S. is a testament to the committed leadership of the Botswana government in finding an HIV vaccine as soon as possible."
The candidate vaccine is assembled from synthetically produced DNA and incorporates small pieces of DNA, which manufacture specific proteins like the ones in HIV. These proteins have elements referred to as epitopes, which in this case prepare the body to recognize real HIV.
No live HIV is used in the vaccine candidate, so there is no way for volunteers to develop HIV from the vaccine.
Research scientists have designed the study as a randomized, double-blinded, multicenter trial. Participants will be healthy, HIV-uninfected adults between ages 18 and 40, all who will have 12 clinic visits, including four injection dates and 12 blood draws.
Volunteers are being screened to see whether they qualify for enrollment, reports Corey. As each volunteer is enrolled, he or she will receive the vaccine injections over a six-month course followed by a year of observation. Researchers anticipate that preliminary study results will be available in the first half of 2005, Corey estimates. (CTU reported on earlier vaccine trials in its STD Quarterly articles, "World’s first large-scale HIV vaccine trial doesn’t indicate protection for overall population," May 2003 issue, and "HIV vaccines: New generation may reduce transmission of virus," October 2002 issue.)
In the fight against HIV, vaccine development must be global, stresses Corey, who also serves as professor in the School of Medicine at the University of Washington and head of the program in infectious diseases at the Fred Hutchinson Cancer Research Center, both in Seattle.
"It is of prime importance to establish a truly global enterprise that will facilitate the rapid development and eventual dispersal of vaccines, thus expediting their use in the areas of the world most affected by disease," he says. "HVTN 048 is one of the initial steps in building this needed foundation for global vaccine research."
1. Fleming P, Byers RH, Sweeney PA, et al. HIV prevalence in the United States, 2000. Presented at the Ninth Conference on Retroviruses and Opportunistic Infections. Seattle; February 2002.
2. Advancing HIV prevention: New strategies for a changing epidemic — United States, 2003. MMWR; 52:329-332.
3. Galli RA, et al. Performance characteristics of the MedMira Rapid HIV Screen Test for the detection of antibodies to HIV-1 and HIV-2 in clinical specimens. Abstract No. C-140. Presented at the General Meeting of the American Society for Microbiology. Atlanta; May 1998.
4. Lubega SN, et al. Field trial of the MedMira Rapid HIV Screen Test in an HIV high-prevalence area in the U.S. Abstract No. C-140. Presented at the General Meeting of the American Society for Microbiology. Atlanta; May 1998.