Chemoprophylaxis Vaccination: Phase I Study to Explore Stage-specific Immunity to Plasmodium falciparum in US Adults.

Background: Chemoprophylaxis vaccination with sporozoites (CVac) with chloroquine induces protection against a homologous Plasmodium falciparum sporozoite (PfSPZ) challenge, but whether blood-stage parasite exposure is required for protection remains unclear. Chloroquine suppresses and clears blood-stage parasitemia, while other antimalarial drugs, such as primaquine, act against liver-stage parasites. Here, we evaluated CVac regimens using primaquine and/or chloroquine as the partner drug to discern whether blood-stage parasite exposure impacts protection against homologous controlled human malaria infection.

A Demographic Analysis of Racial/Ethnic Minority Enrollment Into HVTN Preventive Early Phase HIV Vaccine Clinical Trials Conducted in the United States, 2002-2016.

Objectives: Racial/ethnic minority communities in the United States are overrepresented among new HIV diagnoses, yet their inclusion in preventive HIV vaccine clinical trials is inadequate. An analysis of enrollment demographic characteristics from US preventive HIV vaccine clinical trials from 1988 through 2002 showed that enrollment of racial/ethnic minority groups increased. We analyzed enrollment in preventive HIV vaccine clinical trials from 2002 through 2016 and compared our data with data from the previous study, described demographic characteristics of trial participants, and assessed how well this distribution reflected the racial/ethnic distribution of new HIV diagnoses in the United States.

Substance use patterns of HVTN phase I clinical trial participants: Enrollment, risk reduction counseling and retention.

Background: The primary objectives of HIV Vaccine Trials Network (HVTN) phase 1 preventive HIV vaccine clinical trials are to assess safety and immune response to study products. Participant alcohol and drug use may affect adherence, retention, and risk of HIV infection. Data on the effects of substance use are limited to medical care compliance and treatment adherence in HIV infected participants.

Selection of HIV vaccine candidates for concurrent testing in an efficacy trial.

Phase IIb or III HIV-1 vaccine efficacy trials are generally large and operationally challenging. To mitigate this challenge, the HIV Vaccine Trials Network is designing a Phase IIb efficacy trial accommodating the evaluation of multiple vaccine regimens concurrently. As this efficacy trial would evaluate a limited number of vaccine regimens, there is a need to develop a framework for optimizing the strategic selection of regimens from the large number of vaccine candidates tested in Phase I/IIa trials.

Feasibility of Identifying a Female Sex Worker Cohort at High Risk of HIV Infection in the Caribbean for HIV Vaccine Efficacy Trials: Longitudinal Results of HVTN 907.

Background: Identifying cohorts of Caribbean women with HIV infection rates sufficient for inclusion in HIV vaccine efficacy trials has been challenging. HVTN 907 determined the feasibility of identifying and retaining a cohort of women at high risk for HIV acquisition by focusing recruitment on female sex workers (FSWs).

Methods: HIV uninfected FSWs, residing in Haiti, Dominican Republic, and Puerto Rico, who reported unprotected sex and met previously described more stringent site-specific eligibility criteria, were eligible.