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Biomedical subjects

Beryl A Koblin

Publications and source records attributed to Beryl A Koblin.

At least 19 recordsLinked to original sources

Phase 2 study of an HIV-1 canarypox vaccine (vCP1452) alone and in combination with rgp120: negative results fail to trigger a phase 3 correlates trial.

BACKGROUND: A goal of T-cell HIV vaccines is to define the correlation between a vaccine-induced immune response and protection from HIV infection. We conducted a phase 2 trial to determine if a canarypox vaccine candidate (vCP1452) administered with rgp120 subunit protein would "qualify" for a trial to define a correlate of efficacy. METHODS: A total of 330 healthy volunteers were enrolled into 4 groups: 120 received vCP1452 alone (0, 1, 3, and 6 months), 120 received vCP1452 with 2 different regimens of rgp120 coadministration, and 90 received placebo. HIV-specific antibody responses were measured by enzyme-linked immunoassay (ELISA) and neutralizing activity. T-cell responses were measured by chromium release and interferon-gamma (IFNgamma) enzyme-linked immunospot (ELISpot) assay. RESULTS: Significant neutralizing antibody responses to the HIV MN strain were detected in all vaccine groups, with net responses ranging from 57% (95% confidence interval [CI]: 40% to 71%) to 94% (95% CI: 85% to 99%). Net cumulative HIV-specific CD8 IFNgamma ELISpot assay responses were 13% (95% CI: -1% to 26%) for recipients of vCP1452 alone and 16% (95% CI: 2% to 29%) for recipients of vCP1452 plus rgp120. CONCLUSIONS: Overall, the HIV-specific CD8 cytotoxic T lymphocyte (CTL) response was not sufficient to qualify the regimen for a subsequent trial designed to detect an immune correlate of protection requiring a minimum CD8 CTL frequency of 30%.

AIDS Vaccines↗

Perceptions of lifetime risk and actual risk for acquiring HIV among young men who have sex with men.

Among young men who have sex with men (MSM) surveyed in six US cities, we evaluated the magnitude and correlates of perceived lifetime risk for acquiring HIV, and missed opportunities to increase risk perception by providers of health-care and HIV-testing services. Overall, approximately one quarter of young MSM perceived themselves at moderate/high risk for acquiring HIV. Adjusting for demographic, prior testing, and behavioral characteristics, moderate/high perceived risk had the strongest association with unrecognized HIV infection. However, half of the 267 young MSM with unrecognized infection perceived themselves at low lifetime risk for acquiring HIV, and many young MSM with low-risk perception reported considerable risk behaviors. Providers of health-care and HIV-testing services missed opportunities to assess risks and recommend testing for young MSM. To increase HIV testing, prevention providers should intensify efforts to assess, and to increase when needed, perceptions of lifetime risks for acquiring HIV among young MSM.

AIDS Serodiagnosis↗

Durable HIV-1 antibody and T-cell responses elicited by an adjuvanted multi-protein recombinant vaccine in uninfected human volunteers.

BACKGROUND: Use of the recombinant proteins NefTat and gp120(W61D) formulated with the AS02A adjuvant system was previously shown to protect against AIDS in a rhesus macaque SHIV animal model system. METHODS: Eighty-four HIV uninfected human participants were vaccinated intramuscularly at 0, 1, and 3 months and evaluated for safety. Immune responses were analyzed for the presence of vaccine-induced antibody and T lymphocyte responses. RESULTS: The vaccines were safe and well tolerated at all doses. Nef-, Tat-, and gp120-specific binding antibodies were induced in all individuals that received the respective antigen, lasting up to 9 months after the final immunization. Antibodies able to neutralize the T-cell laboratory-adapted strain of HIV-1(W61D) were detected in the majority of vacinees, but did not neutralize primary isolates. Envelope-specific antibody-dependent cell cytoxicity was detected in most of the individuals receiving gp120. Robust and persistent HIV-specific lymphoproliferative responses were detected against all subunit proteins in the majority of immunized participants. As expected, HIV-specific CD8 T-cell responses were not detected. CONCLUSIONS: Despite the lack of primary isolate neutralizing antibody induction, the observed high frequency and magnitude of other immune responses warrant further work with this vaccine or vaccine components.

AIDS Vaccines↗

Unintentional HIV exposures from young men who have sex with men who disclose being HIV-negative.

OBJECTIVE: To evaluate the proportion of new sexual partners potentially exposed to HIV from young MSM who disclosed being HIV-negative. DESIGN: Cross-sectional, observational study of men aged 23-29 years recruited from randomly sampled MSM-identified venues in six US cities. METHODS: Participants were interviewed and tested for HIV. Analyses were restricted to MSM who reported last testing HIV-negative and having one or more new partners in the prior 6 months. RESULTS: Of 1701 MSM who reported a total of 11 793 new partners, 1075 (63%) disclosed being HIV-negative to 4253 (36%) new partners before having sex with them for the first time. Of disclosers, 352 (33%) reported last testing HIV-negative > 1 year before their interview and 80 (7%) tested HIV-positive (HIV-infected unaware). By race, 24% of black, 5% of Hispanic, and 3% of white disclosers tested HIV-positive. Of the 4253 new partners, 296 (7%) were partners of the 80 HIV-infected unaware MSM. By race, 22% of new partners of black, 3% of new partners of Hispanic, and 4% of new partners of white MSM, were partners of HIV-infected unaware MSM who disclosed being HIV-negative. CONCLUSIONS: Many new sex partners may be unintentionally exposed to HIV from young MSM, particularly those who are black and who disclose being HIV-negative based on an earlier test. Young MSM should test for HIV more frequently and consistently use condoms with all partners unless they are in a mutually monogamous relationship in which both partners have tested HIV-negative at least 3 months since their last potential HIV exposure.

Adult↗

Risk factors for HIV infection among men who have sex with men.

OBJECTIVES: Risk factors for HIV acquisition were examined in a recent cohort of men who have sex with men (MSM). DESIGN: A longitudinal analysis of 4295 HIV-negative MSM enrolled in a randomized behavioral intervention trial conducted in six US cities. METHODS: MSM were enrolled and assessed for HIV infection and risk behaviors semi-annually, up to 48 months. RESULTS: In multivariate analysis, men reporting four or more male sex partners, unprotected receptive anal intercourse with any HIV serostatus partners and unprotected insertive anal intercourse with HIV-positive partners were at increased risk of HIV infection, as were those reporting amphetamine or heavy alcohol use and alcohol or drug use before sex. Some depression symptoms and occurrence of gonorrhea also were independently associated with HIV infection. The attributable fractions of high number of male partners, use of alcohol or drugs before sex, and unprotected receptive anal intercourse with unknown status partners and the same with presumed negative partners accounted for 32.3, 29.0, 28.4 and 21.6% of infections, respectively. CONCLUSIONS: The challenge is to develop strategies to identify men in need. Interventions are needed to help men reduce their number of sexual partners, occurrences of unprotected anal intercourse, alcohol or drug use before sex and address other mental health issues.

Adult↗

Associations between substance use and sexual risk among very young men who have sex with men.

OBJECTIVE: To determine if an association exists in young men who have sex with men (MSM) between being under the influence of alcohol or drugs during sex and participation in sexual behaviors which increase the risk of human immunodeficiency virus (HIV). STUDY DESIGN: A total of 3492 young MSM were interviewed through the Young Men's Survey, an anonymous, cross-sectional, multisite, venue-based survey conducted from 1994 through 1998 at 194 public venues frequented by MSM aged 15 to 22 years in 7 US cities. RESULTS: The majority of young MSM reported both receptive and insertive anal intercourse, and of these, approximately half reported not using condoms. Report of unprotected receptive anal intercourse at least once in the prior 6 months was associated with being under the influence of alcohol (adjusted odds ratio [AOR]=1.5; 95% confidence interval [CI]=1.2-1.8), cocaine (AOR=1.6; 95% CI=1.1-2.2), amphetamines (AOR=1.5; 95% CI=1.1-2.0) or marijuana during sex (AOR=1.3; 95% CI=1.1-1.6). Report of unprotected insertive anal intercourse at least once in the prior 6 months was associated with being under the influence of alcohol (AOR=1.2; 95% CI=1.0-1.5), cocaine (AOR=1.5; 95% CI=1.1-2.0) or amphetamines (AOR=1.9; 95% CI=1.4-2.6). CONCLUSIONS: HIV prevention strategies for young MSM need to incorporate substance use risk reduction.

Adolescent↗

Recent HIV testing among young men who have sex with men: correlates, contexts, and HIV seroconversion.

OBJECTIVES: We evaluated the correlates and contexts of HIV testing within the past year, subsequent risk reduction, and HIV seroconversion among young men who have sex with men (MSM). METHODS: Young men aged 23 to 29 years were approached, interviewed, counseled, and tested for HIV at 181 randomly sampled MSM-identified venues in six U.S. cities from 1998 through 2000. Analyses were restricted to 2,797 MSM who reported never testing HIV-positive. RESULTS: Of the 2,797 MSM, 1,281 (46%) either never previously tested or had not tested in the past year (never/remote testers); 1,516 (54%) had tested in the past year (recent testers); and 271 (10%) tested HIV-positive as part of the study. Of 1,885 recent sex partners reported by HIV-infected participants, 68% were partners of never/remote testers. Of recent testers, 50% tested anonymously, 51% tested because of specific risks, 59% were counseled, 47% reported reducing their risks after testing, and 8% tested HIV-positive (percent HIV-infected by race: blacks, 24%; Hispanics, 6%; whites, 4%; Asians, 1%). CONCLUSION: Nearly half of young MSM participants had not tested in the past year and HIV-infected never/remote testers accounted for approximately two thirds of recent partners potentially exposed to HIV. Of those who had tested recently, many MSM, especially those who are black, had already acquired HIV. To reduce HIV transmission and facilitate early diagnosis and entry into care, increased HIV testing among young at-risk MSM in the United States, especially those who are black, is needed.

AIDS Serodiagnosis↗

Race/ethnic differences in HIV prevalence and risks among adolescent and young adult men who have sex with men.

The prevalence of HIV infection is disproportionately higher in both racial/ethnic minority men who have sex with men (MSM) and in men under the age of 25, where the leading exposure category is homosexual contact. Less is known, however, about patterns of HIV prevalence in young racial/ethnic minority MSM. We analyzed data from the Young Men's Survey (YMS), an anonymous, cross-sectional survey of 351 MSM in Baltimore and 529 MSM in New York City, aged 15-22, to determine whether race/ethnicity differences exist in the prevalence of HIV infection and associated risk factors. Potential participants were selected systematically at MSM-identified public venues. Venues and associated time periods for subject selection were selected randomly on a monthly basis. Eligible and willing subjects provided informed consent and underwent an interview, HIV pretest counseling, and a blood draw for HIV antibody testing. In multivariate analysis, adjusted for city of recruitment and age, HIV seroprevalence was highest for African Americans [adjusted odds ratio (AOR) = 12.5], intermediate for those of "other/mixed" race/ethnicity (AOR = 8.6), and moderately elevated for Hispanics (AOR = 4.6) as compared to whites. Stratified analysis showed different risk factors for HIV prevalence in each ethnic group: for African Americans, these were history of sexually transmitted diseases (STDs) and not being in school; for Hispanics, risk factors were being aged 20-22, greater number of male partners and use of recreational drugs; and for those of "other/mixed" race/ethnicity, risk factors included injection drug use and (marginally) STDs. These findings suggest the need for HIV prevention and testing programs which target young racial/ethnic minority MSM and highlight identified risk factors and behaviors.

Adolescent↗

High-dose recombinant Canarypox vaccine expressing HIV-1 protein, in seronegative human subjects.

BACKGROUND: In clinical trials, canarypox ALVAC-human immunodeficiency virus (HIV) vaccines have been shown to elicit human HIV-specific cytotoxic T lymphocyte (CTL) responses in some but not all healthy uninfected adults.Methods. A clinical trial was conducted to examine whether the vaccine vCP1452 would elicit a greater HIV-specific CTL response when given at a dose of 10(8.0) TCID50 (60 participants) than when given at the regular dose, 10(7.26) TCID50 (40 participants); as a control, a placebo vaccine preparation also was administered (10 participants). RESULTS: Two weeks after the last vaccination in a series, HIV-specific CTL responses were not significantly different when measured by either chromium-release assay (8% and 16% in the high- and regular-dose recipients, respectively) or interferon- gamma ELISpot assay (8% and 15% in the high- and regular-dose recipients, respectively); moreover, recipients of the higher dose had greater local and systemic reactions (P<.001). CONCLUSIONS: High reactogenicity associated with an increased dose of vCP1452 negates the need for further evaluation of this strategy to boost the frequency of HIV-specific CTL response in seronegative human subjects. Development of highly immunogenic canarypox vectors requires further work to optimize vector and insert design, as well as novel ways to increase dosage and to reduce reactogenicity.

AIDS Vaccines↗

Sexual risk, nitrite inhalant use, and lack of circumcision associated with HIV seroconversion in men who have sex with men in the United States.

Men who have sex with men (MSM) continue to account for the largest number of new HIV infections in the United States, but limited data exist on independent risk factors for infection beyond the early 1990s. The HIV Network for Prevention Trials Vaccine Preparedness Study enrolled 3257 MSM in 6 US cities from 1995 to 1997. HIV seroincidence was 1.55 per 100 person-years (95% confidence interval: 1.23-1.95) over 18 months of follow-up. On multi-variable analysis using time-dependent covariates, independent risk factors for HIV seroconversion were increased number of reported HIV-negative male sex partners (adjusted odds ratio (AOR) = 1.14 per partner, population attributable risk (PAR) = 28%), nitrite inhalant use (AOR = 2.2, PAR = 28%), unprotected receptive anal sex with an HIV unknown serostatus partner (AOR = 2.7, PAR = 15%) or HIV-positive partner (AOR = 3.4, PAR = 12%), protected receptive anal sex with an HIV-positive partner (AOR = 2.2, PAR = 11%), lack of circumcision (AOR = 2.0, PAR = 10%), and receptive oral sex to ejaculation with an HIV-positive partner (AOR = 3.8, PAR = 7%). Having a large number of male sex partners, nitrite inhalant use, and engaging in receptive anal sex explained the majority of infections in this cohort and should be targeted in prevention strategies for MSM.

Administration, Inhalation↗

Unrecognized HIV infection, risk behaviors, and perceptions of risk among young men who have sex with men: opportunities for advancing HIV prevention in the third decade of HIV/AIDS.

This study evaluated the magnitude and distribution of unrecognized HIV infection among young men who have sex with men (MSM) and of those with unrecognized infection, the prevalence and correlates of unprotected anal intercourse (UAI), perceived low risk for infection, and delayed HIV testing. MSM aged 15-29 years were approached, interviewed, counseled, and tested for HIV at 263 randomly sampled venues in 6 US cities from 1994-2000. Of 5649 MSM participants, 573 (10%) tested positive for HIV. Of these, 91% of black, 69% of Hispanic, and 60% of white MSM (77% overall) were unaware of their infection. The 439 MSM with unrecognized infection reported a total of 2253 male sex partners in the previous 6 months; 51% had UAI; 59% perceived that they were at low risk for being infected; and 55% had not tested in the previous year. The HIV epidemic among MSM in the United States continues unabated, in part, because many young HIV-infected MSM are unaware of their infection and unknowingly expose their partners to HIV. To advance HIV prevention in the third decade of HIV/AIDS, prevention programs must reduce unrecognized infection among young MSM by increasing the demand for and availability of HIV testing services.

Acquired Immunodeficiency Syndrome↗

Increased high risk sexual behavior after September 11 in men who have sex with men: an Internet survey.

Numerous studies on the mental health effects of terrorist attacks have been published, with some reporting increases in smoking and drug and alcohol use. None have reported on changes in sexual behavior. To investigate the impact of the September 11 attacks on sexual and drug- and alcohol-using behaviors of men who have sex with men (MSM), an anonymous Internet survey was conducted to obtain information retrospectively on behavior during three month periods before and after the attacks. A total of 2,915 MSM from all 50 U.S. states completed the survey. Men who were exposed to the attacks were not differentially targeted for the survey since the online banner ad used to recruit did not mention September 11. Exposure to the attacks varied: 11.4% lost a friend or relative; 5% witnessed the attacks in person; and nearly all saw the attacks on television within one hour of their occurrence. Nearly equal proportions of men reported increases and decreases in the number of sex partners following September 11. Small, statistically significant increases in unprotected anal intercourse and alcohol use, but not illicit drug use, were found when behavior after September 11 was compared to that before the attacks. Men who lost a friend or relative in the attacks were significantly more likely to report unprotected anal intercourse, an increased number of sex partners, and increased alcohol use after September 11 than those who did not. Counseling about substance abuse and risky sexual behavior should be incorporated into trauma-related programs for adolescents and adults.

Adult↗

Breakthrough infections during phase 1 and 2 prime-boost HIV-1 vaccine trials with canarypox vectors (ALVAC) and booster dose of recombinant gp120 or gp160.

Candidate human immunodeficiency virus (HIV)-1 vaccines that elicit cytotoxic T lymphocytes may modulate HIV infection, requiring a prototype evaluation to assess participants who become infected with HIV. Of 1497 participants in canarypox HIV-1 vaccine prime-boost trials, 28 (1.9%) acquired HIV-1 infection after vaccination. Median plasma HIV-1 RNA levels (vaccinees, 4.78 log10 copies/mL; placebo recipients, 4.27 log10 copies/mL) and CD4 cell counts (vaccinees, 552 cells/mm3; placebo recipients, 657 cells/mm3) before administration of antiretroviral therapy (ART) and time to a composite end point (plasma HIV-1 RNA level >55,000 copies/mL, CD4 cell count <350 cells/mm3, or initiation of ART) did not differ significantly between vaccinees and placebo recipients (P =.4, P =.1, and P =.7, respectively). Persons who acquire HIV-1 infection while enrolled in HIV-1 vaccine trials can be successfully followed after infection, to determine whether vaccines alter the course of HIV-1 infection.

AIDS Vaccines↗

Associations of race/ethnicity with HIV prevalence and HIV-related behaviors among young men who have sex with men in 7 urban centers in the United States.

Using data from a multisite venue-based survey of male subjects aged 15 to 22 years, we examined racial/ethnic differences in demographics, partner type, partner type-specific condom use, drug use, and HIV prevalence in 3316 US black, multiethnic black, Latino, and white men who have sex with men (MSM). We further estimated associations of these factors with HIV infection and their influence on racial/ethnic disparities in HIV prevalence. HIV prevalences were 16% for both black and multiethnic black participants, 6.9% for Latinos, and 3.3% for whites. Paradoxically, potentially risky sex and drug-using behaviors were generally reported most frequently by whites and least frequently by blacks. In a multiple logistic regression analysis, positive associations with HIV included older age, being out of school or work, sex while on crack cocaine, and anal sex with another male regardless of reported condom use level. Differences in these factors did not explain the racial/ethnic disparities in HIV prevalence, with both groups of blacks experiencing more than 9 times and Latinos experiencing approximately twice the fully adjusted odds of infection compared with whites. Understanding racial/ethnic disparities in HIV risk requires information beyond the traditional risk behavior and partnership type distinctions. Prevention programs should address risks in steady partnerships, target young men before sexual initiation with male partners, and tailor interventions to men of color and of lower socioeconomic status.

Adolescent↗

Randomized, controlled evaluation of a prototype informed consent process for HIV vaccine efficacy trials.

Procedures must be developed to ensure that valid informed consent is obtained from participants in HIV vaccine efficacy trials. A prototype informed consent process was evaluated among 4,892 persons at high risk for HIV infection in the HIV Network for Prevention Trials Vaccine Preparedness Study (VPS), a prospective cohort study of HIV seroincidence in eight U.S. metropolitan areas. Twenty percent of VPS participants were selected at random to undergo the prototype informed consent process at VPS month 3. Participants' knowledge of 10 key HIV vaccine trial concepts and willingness to participate in HIV vaccine efficacy trials were assessed and compared at baseline and semiannually thereafter for 18 months. Knowledge of HIV vaccine trial concepts was low at baseline. Participation in the prototype process was associated with substantial and sustained increases in knowledge (relative risks for the 10 items, 1.04-2.26), which were of similar magnitude across HIV risk groups, race/ethnicity, and educational levels. It is recommended that the prototype informed consent process be adopted for future HIV vaccine efficacy trials as well as for clinical trials in other research areas.

AIDS Vaccines↗

Herpes simplex virus type 2 infection as a risk factor for human immunodeficiency virus acquisition in men who have sex with men.

The association of human immunodeficiency virus (HIV) acquisition with herpes simplex virus type 2 (HSV-2) was assessed among men who have sex with men (MSM) in a nested case-control study of 116 case subjects who seroconverted to HIV during follow-up and 342 control subjects who remained HIV seronegative, frequency-matched by follow-up duration and report of HIV-infected sex partner and unprotected anal sex. The baseline HSV-2 seroprevalence was higher among case (46%) than control (34%) subjects (P=.03); the HSV-2 seroincidence was 7% versus 4% (P=.3). Only 15% of HSV-2-infected MSM reported herpes outbreaks in the past year. HIV acquisition was associated with prior HSV-2 infection (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-2.9), reporting >12 sex partners (OR, 2.9; 95% CI, 1.4-6.3), and reporting fewer herpes outbreaks in the past year (OR, 0.3; 95% CI, 0.1-0.8). HSV-2 increases the risk of HIV acquisition, independent of recognized herpes lesions and behaviors reflecting potential HIV exposure. HSV-2 suppression with antiviral therapy should be evaluated as an HIV prevention strategy among MSM.

Case-Control Studies↗

Hepatitis C virus infection among noninjecting drug users in New York City.

The prevalence of hepatitis C virus (HCV) infection among noninjecting drug users has been reported to be higher than in the general population, but the reasons for this observation remain unclear. Noninjecting drug users aged 15-40 years and who used drugs for no longer than 10 years were enrolled in the study. The participants were interviewed about risk behaviors and had specimens drawn for serological testing. Of 276 enrolled, 4.7% were infected with HCV. Drug users who had ever sniffed or snorted heroin in combination with cocaine were significantly more likely to be infected with HCV compared with those who never sniffed or snorted heroin with cocaine. No other drug use or sexual risk behaviors were found to be associated with HCV infection. These findings suggest that sniffing or snorting heroin with cocaine may explain the increase frequently found in HCV infection among noninjectors, but further studies are necessary.

Administration, Intranasal↗