Do new data refute the antigenic diversity threshold theory of AIDS pathogenesis? Yes, say Northwestern University researcher Steven M. Wolinsky and colleagues, who published a paper to this effect in the journal Science (1996;272(5261):537-542, see AIDS Weekly Plus, May 20, 1996). No way, say University of Oxford researcher Martin A. Nowak and colleagues, who developed the theory in 1990 (AIDS, 1990;4:1095) and defended it against Wolinsky et al. in a recent issue of Science ("HIV-1 Evolution and Disease Progression," Science, 1996;274(5289):1008-11).
A subset of people with a type of autoimmune disease may be naturally immune to HIV. The finding, reported by University of Southern California researcher Angeline Douvas and colleagues, could be of great importance in the development of an HIV vaccine. It also hints that an unknown retrovirus may play a role in the autoimmune syndrome known as mixed connective tissue disease (MCTD).
There is much more HIV in the lymphoid tissues of an infected person than in the blood. The bad news is that these infectious virions apparently are not affected by inhibitors of HIV reverse transcriptase. The good news is that they can be measured by a new technique that can estimate HIV viral load in lymphoid tissues reliably from relatively non-invasive outpatient tonsil biopsies.
Brazil, concerned about the risk of HIV infection among Indians, launched a campaign to educate tribes about the dangers of AIDS and ways of preventing the spread of sexually-transmitted disease (STD).
Fear-based AIDS prevention messages have failed. Nearly one in five Americans with AIDS were infected with HIV in their teenage years; by the age of 21, more than a quarter of youths have acquired a sexually transmitted disease. Faced with this apparent failure - and with limited funding - there is a growing sense that AIDS education should be limited to those perceived to be most at risk.
Additional client services are needed to assist impoverished and poorly educated AIDS patients. "The challenges are different now that the gay-white-male era is over," declared Jean Grier, Director of Client Services for AID Atlanta, Georgia. "Long gone are the days when you could assume your client came to the table well informed."
Community involvement is the key to current and future CDC AIDS prevention programs, said the agency's AIDS chief. "We look forward to changing the number of new HIV infections in this country to zero," said Helene Gayle, director of the National Center for HIV, STD, and TB Prevention, U.S. Centers for Disease Control and Prevention (CDC), Atlanta, Georgia.
Progesterone implants increased vaginal simian immunodeficiency virus (SIV) transmission nearly eight fold in female monkeys. Several of the progesterone-treated animals also appeared to have accelerated progression of SIV disease compared to untreated controls.
Tailor the vaccine to fit the genes, suggests a leader of the U.S. HIV vaccine effort. After reviewing the history and present status of HIV vaccine research, Duke University AIDS Center researcher Barton F. Haynes concluded that a successful AIDS vaccine will have to account for extensive genetic variability not only in the virus, but also in human populations.
The TB/HIV Research Laboratory at the International Health Institute of Brown University has announced the launch of a new tool for HIV vaccine research. The product, EpiMatrix/HIV, was developed at Brown University and implemented for the Internet by AVX Design Inc., Providence, Rhode Island.
HIV infected individuals with weak anti-p55 antibodies are nearly eight times more likely to have rapid disease progression. The data come from a study of Western blot reactivity patterns among U.S. Navy and Marine Corps personnel who tested positive for HIV between 1986 and 1991.
A new anti-HIV vaccine would induce antibodies against a free-floating HIV protein instead of the virus itself. The HIV transcriptional activation (Tat) protein is essential for high-level HIV replication. But the protein has a non-transcriptional role as well: Tat released by HIV infected cells readily enters and activates uninfected cells, rendering them susceptible to HIV infection.
An experimental AIDS vaccine failed to boost key antibodies in people with HIV infection. The vaccine, p24-VLP, contains HIV-1 p17 and p24 core antigens in the form of virus-like particles (VLP) expressed in yeast via a genetically engineered transposon (Ty)/p17/p24 fusion gene. It is being developed by British Biotech Pharmaceuticals Ltd., Oxford, England.
The incidence of tuberculosis among HIV positive persons in Brooklyn, New York appears to be lower than previously suggested, according to a city-wide TB surveillance program. Researcher B.S. Ravi and colleagues from Brooklyn's New York Methodist Hospital also found that the majority of cases of TB among HIV infected individuals were the result of reactivation rather than recent transmission.
Antibodies induced by bacterial vaccines fade rapidly in children with congenital HIV infection. The finding suggests that HIV(+) children, who are at increased risk of bacterial infections, may need more frequent booster immunizations than normal children.
The sudden increase in HIV viral load previously reported to occur in response to vaccination is inconsistent and transient, new studies show. Several workers have documented sudden dramatic increases in HIV levels following vaccination.
Advanced clinical trials of HIV vaccines should be conducted in developing nations, the United Nations argues. And through its UNAIDS organization, the U.N. is preparing to begin such trials in Brazil, Thailand, and Uganda. "It is impractical, if not unethical, to leave developing countries out of the HIV vaccine development process," said UNAIDS executive Saladin Osmanov.
In cooperation with the U.S. Centers for Disease Control and Prevention (CDC), Thai researchers have found a population ideal for testing experimental HIV vaccines. Among intravenous drug users (IDUs) in Bangkok, Thailand, HIV incidence is 10 percent per year. Some 8,000 of these individuals are currently enrolled in drug-treatment centers managed by the Bangkok Metropolitan Administration (BMA).
A three-year study in France found only a moderate prevalence of multidrug-resistant tuberculosis among HIV positive persons. Researcher Valerie Schwoebel and colleagues from Paris' Institut Pasteur found that foreign origin was associated with both secondary and primary multidrug-resistant tuberculosis (MDR-TB) in France.
Three of the 33 subjects in Thailand's Phase II trial of the Genentech HIV vaccine became infected with HIV. None of the infections were caused by the vaccine, which contains only the gp120 envelope protein of HIV-1 clade B strain MN. All of the infections were caused by HIV-1 strains belonging to clade E.
Accept the reality that much remains to be learned and move forward with advanced clinical trials of HIV vaccines, a senior U.S. researcher urges. "While the basic research of HIV's immunopathogenesis is of critical importance and should be thoroughly and vigorously pursued, systematic HIV vaccine development should not be immobilized by our current ignorance of these data," said John G. McNeil of the Walter Reed Army Institute of Research, Rockville, Maryland.
Eight years in the making, a novel HIV immunogen can elicit antibodies that neutralize patient isolates from all over the world. Depending on how it is formulated and administered, the immunogen can stimulate either serum or mucosal immune responses in animal studies.
Localized immunizations may be required for mucosal protection against HIV infection. Recipients of the Virogenetics canarypox HIV vaccine had no detectable HIV-specific IgA antibodies in mucosal secretions or saliva.
The mucosa of macaque monkeys is very like that of humans, French researchers say. The unexpectedly close similarity makes it possible to use macaques to study HIV vaccines and other strategies to prevent the transmission of HIV across the vast mucosal surfaces of the body.
A canarypox-based HIV vaccine currently in human trials protected female chimpanzees against vaginal challenge with infectious virus. But exactly how the vaccine worked is unknown: the protected animals had very low levels of antibodies capable of neutralizing HIV, and had no detectable anti-HIV antibodies in their vaginal mucosa at the time of challenge.
When administered with vitamin D3, a DNA vaccine encoding an HIV antigen induces what appears to be a common mucosal immune response in mice. The immunization protocol apparently is suitable for human testing. "This should be well tolerated in humans," said William M. Mitchell of Vanderbilt University, Nashville, Tennessee.
We think we know how HIV infects the body but we don't know. And it's high time to find out. The vast majority of HIV infections take place across mucosal surfaces. But as Marc Girard of the Pasteur Institute, Paris, has pointed out, very little is known about how these infections occur. Even less is known about what kinds of immune responses should be evoked to prevent them.
Passive immunization with a single genetically engineered human antibody offered complete protection against a number of HIV strains in an animal model. The recombinant human monoclonal antibody (mAb) is called IgG1 b12. "This antibody is being developed for immunoprophylaxis and immunotherapy of HIV-1 infection in humans," said Paul W.H.I. Parren of The Scripps Research Institute, La Jolla, California.
The ability of antibodies to neutralize one of three key HIV isolates predicts their ability to neutralize other isolates. The findings may speed HIV vaccine development by identifying key epitopes for vaccine inclusion and by facilitating the testing of candidate vaccines.
The recently described (beta)-chemokines inhibit HIV by binding to the C-C CKR-5 co-receptor on T cells. Identification of co-receptors necessary for HIV infection of CD4(+) T cells opens up new targets for vaccines. AIDS researcher Paolo Lusso and colleagues recently reported that several cellular factors known as (beta)- chemokines - RANTES, MIP-1(alpha), and MIP-1(beta) - have potent anti-HIV activity.
Clinical trials show that the MicroGeneSys Inc. candidate HIV vaccine has no therapeutic effects in people already infected with the virus.Three separate multicenter Phase II trials of the product, known as VaxSyn, took place in the U.S., Canada, and Sweden.
AIDS-associated Kaposi's sarcoma (KS) cells have an Achilles heel.Researchers have found that KS cells express extremely high levels of the interleukin 13 (IL-13) receptor.
Long a goal of AIDS therapy, the reconstitution of lost CD4(+) T lymphocytes may at last be nearing reality. A breakthrough study shows that proper stimulation of CD4(+) T cells cultured from HIV infected individuals not only causes them to proliferate but also reduces viral load.
An experimental therapeutic AIDS vaccine was safe and showed evidence of efficacy in a Phase II clinical trial. The vaccine, developed by Immunotech SA, Marseille, France, works differently than most vaccines. Instead of inducing antibodies to an antigen, it induces antibodies to an antibody. The so-called idiotypic antibodies raised in this fashion are high ly specific.
Self-administered interleukin 2 (IL-2) can dramatically increase CD4 counts in patients receiving antiretroviral therapy. Previous studies have shown that intravenous infusions of IL-2, given in the right dose for the right amount of time, can restore depleted CD4 counts in patients with HIV disease.
Researchers questing for an AIDS vaccine should apply newly discovered principles of immunoregulation, says immunologist William E. Paul. Paul's comments carry substantial weight, as he is director of the Office of AIDS Research at the National Institutes of Health.
Patients receiving anti-HIV drugs have increased T-cell numbers, but the immune function of these new cells is impaired.The hallmark of HIV disease is a marked decrease in CD4(+) T cells. Antiretroviral therapies have long been evaluated in terms of their ability to reverse this trend.
The first human trials of a naked HIV DNA vaccine show the vaccine to be safe and suggest that it is immunogenic.Extensive animal studies show that the vaccine can be used both to treat and to prevent HIV infection.
There is still no cure for AIDS.It says so right there in the patient-information section of the package inserts for the three U.S.- approved protease inhibitors: saquinavir (Hoffman-LaRoche's Invirase), indinavir (Merck's Crixivan), and ritonavir (Abbott's Norvir).
Women who remain uninfected despite frequent sexual exposure to HIV have high numbers and percentages of natural killer cells.No other immunologic differences could be found between these highly exposed, persistently seronegative (HEPS) women and either infected women or a normal reference population.
How do they do it? Exhaustive immunological studies of Zambian women who remain uninfected despite repeated sexual exposure to HIV revealed only one difference from matched, unexposed women.
The most effective AIDS vaccines may be those that boost innate anti-HIV immune responses. Monkeys protected against simian immunodeficiency virus (SIV) infection by a live attenuated SIV vaccine developed cytotoxic lymphocyte (CTL) responses specific for the SIV Nef protein - even though the vaccine lacked a functional nef gene.
Do you have to know what you are looking for before you can find it? Nobody knows what kinds of immune responses protect people against HIV infection and/or HIV disease. But the following stories in this issue represent the world's best efforts to find out.
A powerful new type of anti-HIV drug prevents the virus from entering human cells. Human tests of the first of these new "fusion inhibitors" are scheduled for later this year, according to U.S. Food and Drug Administration (FDA) researcher Paul L. Black.
The new anti-HIV drug known as 1592U89 succinate appears to be the most effective nucleoside reverse transcriptase inhibitor ever tested in humans. Early data from clinical trials show that the drug, nicknamed U89, carries as strong an initial anti-HIV punch as the new protease inhibitors.
Medicinal plants used by native Bolivian healers contain potent new anti-HIV compounds. The traditional medicinals do what scientifically designed molecules thus far cannot: inhibit the HIV-1 integrase enzyme.
Is the main determinate of HIV disease the virulence of the virus or the susceptibility of the infected person? This unresolved question looms large in the quest for an HIV vaccine. "It's the virus, stupid," says David Ho of New York's Aaron Diamond Research Center.
Genentech researchers say that their gp120 subunit vaccine appears to protect people against some HIV-1 strains. They suggested that a carefully selected cocktail of gp120 subunits might protect against the majority of viral strains in a given population.
Large-scale clinical trials may be the next step for what is now the most promising HIV vaccine strategy. Findings from smaller trials only recently completed provide tantalizing hints that what has come to be called the "prime/boost" approach may yield an effective vaccine.
The optimism fueled by the advent of effective anti-HIV drugs is a cruel joke to nations unable to afford even basic medicines. Like the mythological figure Tantalus who starves with food dangling just out of reach, the vast majority of people with AIDS will never see the protease inhibitors that have stolen the show at the XI International Conference on AIDS, held July 7-12, 1996, in Vancouver, British Columbia, Canada.
Is it time to test candidate HIV vaccines in advanced clinical trials? Those who say no point to the scanty amount of evidence that current vaccines will be able to induce meaningful immunity outside of the test tube. They also argue that to test now would be a great waste of valuable resources.
The good news: HIV is on the run. The bad news: the AIDS pandemic is growing rapidly. The highlight of the XI International Conference on AIDS, to be held July 7-12, 1996, in Vancouver, Canada, will be the presentation of clinical trial results showing that the most potent of the new HIV protease inhibitors - when combined with zidovudine (AZT) and lamivudine (3TC) - can control HIV infection.
Patients taking saquinavir will not be resistant to other protease inhibitors, clinical data suggests. In vitro studies have shown that when HIV develops resistance to saquinavir (Invirase, Roche) it also becomes resistant to other protease inhibitors.
Ritonavir, Abbott's entry in the HIV protease-inhibitor sweepstakes, is highly effective in combination with other anti-HIV drugs. The data described by senior Abbott researcher Akhter Molla is expected to be released during the July 1996 XI International Conference on AIDS in Vancouver, Canada.
Another of the new HIV protease inhibitors is being tested in a potent triple combination. Nelfinavir mesylate (Agouron Pharmaceuticals Inc.) is the latest entry in what is now a field of four protease inhibitors being tested in combination with nucleoside-analog reverse-transcriptase inhibitors.
A new finding casts doubt on the safety of influenza vaccination for HIV infected individuals. Previous studies have detected a transient increase in the blood levels of people with HIV infection after influenza vaccination (e.g., D.D. Ho, Lancet, 1992;339:1549 and O'Brien et al., Blood, 1995;86:1082-9).
A three-drug combination has set a new standard for AIDS therapies. Copies of HIV RNA - now considered the best surrogate marker for HIV disease - dropped to undetectable levels (below 200 copies/ml) in the plasma of more than 90 percent of subjects receiving the triple combination of the protease inhibitor indinavir (Crixivan, Merck), zidovudine (AZT, Glaxo- Wellcome), and lamivudine (3TC, Glaxo-Wellcome).
Long-lived peptide-grafted immunoglobulin molecules can induce tolerance in vivo. These molecules could be used in future gene therapies that one day might:
An inactivated bacterium conjugated to HIV peptides creates a vaccine capable of eliciting HIV specific cellular immunity in mice. Remarkably, the Brucella abortus-conjugated vaccine had the same effect in mice with no CD4(+) T cells.
At the same time its anti-HIV properties were announced, a new drug entered clinical trials in Europe. The drug, 1,1'-azobisformamide or ADA, is an azoic compound with a molecular weight of 116.08 and the structural formula H[2]N-OC-N=N-CO-NH[2].
A new acyclic nucleotide is just as potent - and, in laboratory studies, nine times less toxic - than adefovir (PMEA). PMEA [9-(2-phosphonylmethoxyethyl)-adenine] is the prototypic compound for a new class of drugs active against HIV, herpesviruses, and hepatitis viruses. Unlike nucleoside analogs (AZT, ddI, ddC, d4T, etc.), these nucleotide analogs are already in their active form and do not require intracellular processing for activation.
Vigorous HIV specific cytotoxic lymphocyte (CTL) responses and paradoxically weak neutralizing antibody activity characterize the immune responses of long-term survivors with the lowest viral loads. The finding has direct implications for HIV vaccine research.
A new finding overturns a long-held belief about the natural history of HIV infection. Soon after a person is first infected with HIV there is a short burst of high-titer viremia. This viremia quickly subsides.
The recent mergers of the largest pharmaceutical benefits managers (PBMs) with large drug companies "have created the potential for conflicts of interest," a Georgetown University study suggests. According to some predictions, PBMs will control some 75 percent of the U.S. pharmaceutical market by the year 2000.
Long-term follow-up of the first patients to receive a therapeutic HIV vaccine shows that those who responded to the vaccine have had a relatively favorable clinical course.
It works - but how? The success of an attenuated SIV vaccine in monkeys has U.S. researchers arguing over whether an attenuated HIV vaccine could ever be safe enough for humans.
A small retroviral protein can be used to incorporate a foreign enzyme into virions, suggesting a new antiviral approach. The protein, Vpx, is the product of the regulatory gene vpx found in the primate lentiviruses HIV-1, HIV-2, and SIV. The function of Vpx is not well understood, but it does not appear to be essential for virus replication.
New data refute popular hypotheses of AIDS pathogenesis and point to the immune system as the most important means of controlling HIV. HIV has an extraordinary ability to mutate into new quasispecies within an infected individual. This observation has led many researchers to conclude that the characteristic loss of CD4(+) T lymphocytes in AIDS occurs when the increasing antigenic diversity of HIV quasispecies overwhelms the immune system (Nowak et al., Science, 1991;254:963).
Overall, American heterosexuals have done little to reduce their risk of acquiring HIV infection. More than 70 percent of all HIV infections worldwide are transmitted via heterosexual sex. But heterosexuals account for only 7 percent of U.S. AIDS cases. The latest data show that in the U.S., men who have sex with women and women who have sex with men are willing to take their chances.
A human monoclonal antibody and a CD4/IgG chimera potently neutralize HIV in plasma from late-stage AIDS patients. The findings show that both molecules may potentially be used to treat and even to prevent HIV disease. "These studies suggest that IgG1b12 and CD4-IgG2 have broad and potent neutralizing activity in both in vitro and ex vivo neutralization assays and should be considered for use as potential immunoprophylactic or therapeutic agents," wrote Aaron Diamond AIDS Research Center researcher Marie-Claire Gauduin and colleagues.
Subcutaneous inoculation with small amounts of antigen in combination with a steroid hormone induced common mucosal immunity in an animal model. The immunomodulatory effect of the hormone, 1(alpha),25- dihydroxy vitamin D[3] (1,25(OH)[2]D[3]), was further increased by coadministration of dehydroepiandrosterone (DHEA).
The innate immune system - which emerged with the first multicellular organisms - is not just an old fossil. Once thought to be the unnecessary vestigial tail of the immune system, new findings show that innate immunity is the cornerstone of the body's ability to fight infection. This new understanding of immunity has implications for prophylactic and therapeutic manipulations of the immune system to fight bacterial, protozoan, viral, and autoimmune diseases.
The rate of tuberculosis in a group of substance abusers on welfare in New York City was almost 15 times that of the city's general population in a study conducted by Connecticut's Yale University and the U.S. Centers for Disease Control and Prevention (CDC). Researchers noted however that positive skin testing does not accurately assess the likelihood of developing active tuberculosis in this population.
Can a single administration of a peptide-based HIV vaccine induce long-lasting immunity? Genentech Inc., South San Francisco, California, is betting that the answer is yes. Chimpanzee studies show that a single shot of the firm's gp120 HIV vaccine can protect chimpanzees against challenge with infectious, heterologous challenge: but only when the challenge is performed just after the animal achieves peak anti-gp120 antibody titers.
Separate T- and B-cell immune responses to the HIV envelope antigen may protect against HIV infection. The findings offer evidence of correlates of immunity to HIV that may point the way to new vaccine strategies. A third of HIV negative intravenous drug users (IVDUs) tested by an Italian/American research team had antibodies that recognized both HIV and human self antigens.
Whether HIV disease will rapidly progress or remain relatively stable is established very early in the course of infection, new studies confirm. The new data identify stage-independent predictors of disease progression. Examination of these predictors in AIDS- vaccine recipients with breakthrough HIV infection should indicate whether the vaccine can change the course of disease.
The versatile virus-like particle (VLP) produced by the yeast transposon promises to vastly improve particulate antigen vaccines. Simple monomeric proteins are by themselves only poorly immunogenic. But the creation of particulate, polyvalent antigens permits the elicitation of immune responses without the risks posed by live attenuated pathogens.
Pharmaceutical plants of the future may literally be just that. By using genetically engineered plant viruses, researchers now have the ability to turn vegetables into efficient factories for producing vaccine antigens.
Adjunctive therapy with pentoxifylline appears to be marginally beneficial in HIV positive tuberculosis patients, according to a report from Cleveland, Ohio's Case Western University. In a recent study R.S. Wallis and colleagues found that adjuvant treatment with pentoxifylline resulted in statistically significant improvements in plasma HIV RNA and (beta)2 microglobulin, but did not increase survival times in a cohort of HIV positive tuberculosis patients.
Monkeys immunized via direct iliac lymph-node inoculation were protected against rectal challenge with simian immunodeficiency virus (SIV). The findings provide insight into ways vaccines might be used to prevent the sexual transmission of HIV. "No single immune response is protective," said researcher Thomas Lehner of Guys Hospital, London, England.
AIDS among heterosexuals would greatly increase in the U.S. and Europe if HIV strains common in most of the world became established in the west, a leading expert warns. Nearly all HIV vaccines currently in development use antigens derived from U.S. and European strains. But according to Harvard AIDS Institute researcher Max Essex, AIDS is not the same epidemic in all parts of the world.
Hyperimmune plasma from healthy people with HIV infection could prevent disease in some people recently exposed to the virus, monkey studies show. The data also provide a tantalizing glimpse into the unknown: the correlates of protective immunity against HIV. Lack of this knowledge currently hamstrings HIV vaccine research.
The National Institute of Allergy and Infectious Diseases (NIAID) has announced a major program of grants and contracts to support the development of vaccines and other means of preventing AIDS. The program is called the Vaccine and Prevention Research Program (VPRP). It is organized into an associate director's office, a preclinical research branch, a clinical development branch, and an efficacy trials branch.
High doses of a very effective, live attenuated HIV prototype vaccine can kill newborn monkeys, but normal doses are safe, new studies show. The vaccine, SIV[mac239] delta 3, is a live simian immunodeficiency virus (SIV) that has been genetically altered so that it is missing three vital genes: vpr, nef, and the gene encoding the Nef-responsive element (NRE).
Addition of a gene encoding gamma interferon makes a live prototype HIV vaccine both safer and more effective. The vaccine, SIV[mac239] delta 3, under development by Therion Biologics Corp., is a live simian immunodeficiency virus (SIV) that has been genetically altered so that it is missing three vital genes: vpr, nef, and the gene encoding the Nef-responsive element (NRE).
Despite receiving four doses of an experimental HIV-1 vaccine, a clinical trial participant became infected with the AIDS virus. This is the first breakthrough HIV infection in clinical trials of the vaccine being developed by United Biomedical Inc., Hauppauge, New York. Breakthrough infections previously occurred in some participants in early clinical trials of HIV gp120 subunit vaccines.
Nature has provided an answer to a key question in vaccinology: how to stimulate killer T cells with small- peptide-based vaccines. The answer may be of immediate use in the development of HIV vaccines, as cell-mediated immunity appears crucial to control of the AIDS virus. But the finding may apply to other viral and parasitic diseases as well.
A powerful new approach to genetic immunization promises to create highly effective vaccines for AIDS, tuberculosis, and other diseases. The resulting vaccines have the potential for both prophylactic and therapeutic applications.
LAMPS, which already have shed light on improved cancer vaccines, may do the same for HIV vaccines. LAMP, or lysosomal-associated membrane protein, is a major membrane component of cellular polysomal/lysosomal compartments. It is in these compartments that proteins are processed into the major histocompatibility complex type II (MHC-II) pathway leading to stimulation of CD4(+) T- lymphocyte-mediated immune responses.
Only an effective vaccine can stop the global AIDS pandemic, according to veteran AIDS epidemiologist James Curran. Curran, until recently head of the AIDS prevention effort at the U.S. Centers for Disease Control and Prevention (CDC), is now with the Rollins School of Public Health at Emory University, Atlanta, Georgia.
HIV can leapfrog normal evolutionary processes with unpredictable consequences, according to a leading AIDS geneticist. The finding puts yet another obstacle in the path of HIV vaccine development - and raises the specter of HIV becoming more pathogenic and/or more easily transmissible.
UNAIDS, the umbrella agency for United Nations AIDS programs, will promote testing of candidate AIDS vaccines in developing nations, according to agency director Peter Piot. As of January 1, 1996, UNAIDS replaced the United Nations Global Program on AIDS as the U.N.'s major AIDS agency. UNAIDS is co-sponsored by several major U.N. agencies, including the United Nations Children's Fund (UNICEF), the World Bank, the World Health Organization (WHO), the United Nations Family Planning Agency (UNFPA), and the United Nations Educational Scientific and Cultural Organization (UNESCO)
Measures of the amount of HIV in the blood of an infected person predict that person's clinical outcome, according to data from the Multicenter AIDS Cohort Study (MACS). The measures, provided by soon-to-be-available blood tests, can be used not only for clinical decision making but also to evaluate the success of antiretroviral therapies.
There has been a reluctance to accept the "unpleasant" data from HIV vaccine studies, according to a leading British researcher. Because of this reluctance it has been difficult to learn what the data have to offer, said James Stott of England's National Institute for Biological Standards and Control, Hertfordshire, U.K.
They were the graphs and charts AIDS conference attendees have been waiting more than 11 years to see. In a series of slide presentations, researchers conducting clinical trials of HIV protease inhibitors showed that the most potent of these compounds can significantly delay the onset of AIDS and prolong survival.
A genetic trait linked to long-term survival in HIV infected adults helps infants resist getting HIV from their mothers. Conversely, other genetic traits appear to make infants particularly vulnerable to mother-to-child HIV transmission.
HIV(+) adults - particularly travelers - may be at risk of dangerous infections due to impaired antibody responses to booster vaccines. A Dutch study shows that people with HIV infection may not develop protective antibody responses after vaccination if their CD4(+) T-cell counts are lower than 300 cells/(micro)L.
The best funded and best functioning arm of the U.S. AIDS effort must continue to improve, the group's new leader charged. The Pediatric AIDS Clinical Trials Group (PACTG) is part of the AIDS clinical trials program established by the U.S. National Institute of Allergy and Infectious Diseases (NIAID).
Needle-exchange programs work to reduce HIV transmission. Multiple studies from around the world - from New York City to Kathmandu - show that providing clean needles to intravenous drug users (IVDUs) can significantly reduce the spread of AIDS in a highly cost-effective manner.
A new technique so greatly increases the avidity of an anti-HIV antibody that it is capable of neutralizing the virus at picomolar concentrations. The original antibody was already "the most potent and broadly neutralizing human anti-HIV-1 antibody yet described," according to researchers Wei-Ping Yang, Carlos F. Barbas III, and colleagues at the Scripps Research Institute, La Jolla, California.
The novel herpesvirus associated with Kaposi's sarcoma (KS) can be detected in the semen of normal, healthy donors, according to researchers at the U.S. Centers for Disease Control and Prevention (CDC). The virus, known as KS-associated herpesvirus (KSHV) and provisionally dubbed HHV-8, is believed to either cause or be a major cofactor in the development of KS in both AIDS and non-AIDS patients.
The efficacy of vaccines and drugs to prevent mother-to-child HIV transmission cannot be tested in the U.S., according to a Duke University researcher. However, Phase I and II trials in the U.S. are essential for establishing the "proof of concept" for such vaccines and drugs, said Ross McKinney, Clinical Director of the Duke AIDS Clinical Trial Unit.
The largest yet least understood arm of the immune system may be the key to an AIDS vaccine. A growing body of data from epidemiologic field investigations, laboratory experiments, and human studies points to mucosal tissues as the most important sites of HIV infection. These studies also suggest that mucosal immunity is the key to preventing HIV transmission.
Tests performed at the U.S. Centers for Disease Control and Prevention (CDC) showed that a U.S. woman - and her newborn child - were infected with human immunodeficiency virus type 2 (HIV-2). HIV-2 is predominant only in West Africa, although the virus has previously been reported elsewhere. Like HIV-1, HIV-2 can cause AIDS. HIV-2 is more closely related to the simian immunodeficiency viruses (SIVs) than is HIV-1, although both types of HIV are thought to have evolved from a common monkey-virus ancestor.
Intravenous drug users (IDUs) can be capable participants in clinical trials of HIV vaccines. This population has been excluded from the design of clinical trials because of perceived difficulties in recruiting, obtaining informed consent, and maintaining compliance from people who regularly inject themselves with illegal, psychoactive drugs.
New protein-based intracellular immunization techniques could yield new gene therapies against AIDS. Intracellular immunization is a term proposed in 1988 by Nobel Laureate David Baltimore to describe the protection of an individual against an infection by genetically engineering antimicrobial resistance into that person's cells.
HIV viral burden decreased by 99.9 percent in patients receiving a three-drug combination in a Phase II clinical trial. The combination includes indinavir (Merck trade name Crixivan, code-named MK-639 and formerly called L-735,524 or L-524). Indinavir is one of the new class of anti-HIV drugs known as protease inhibitors now reaching advanced clinical trials. One protease inhibitor, saquinavir (Roche trade name Invirase), recently received U.S. approval as an AIDS therapy.
This information is designed to support, not replace, the relationship that exists between you and your doctor.