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We explored the duration of immune responses and the effect of a late third HIV-modified vaccinia virus Ankara (MVA) boost in HIV-DNA primed and HIV-MVA boosted Tanzanian volunteers. Twenty volunteers who had previously received three HIV-DNA and two HIV-MVA immunizations were given a third HIV-MVA immunization 3 years after the second HIV-MVA boost. At the time of the third HIV-MVA, 90% of the vaccinees had antibodies to HIV-1 subtype C gp140 (median titer 200) and 85% to subtype B gp160 (median titer 100). The majority of vaccinees had detectable antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies, 70% against CRF01_AE virus-infected cells (median titer 239) and 84% against CRF01_AE gp120-coated cells (median titer 499). A high proportion (74%) of vaccinees had IFN-γ ELISpot responses, 63% to Gag and 42% to Env, 3 years after the second HIV-MVA boost. After the third HIV-MVA, there was an increase in Env-binding antibodies and ADCC-mediating antibodies relative to the response seen at the time of the third HIV-MVA vaccination, p < .0001 and p < .05, respectively. The frequency of IFN-γ ELISpot responses increased to 95% against Gag or Env and 90% to both Gag and Env, p = .064 and p = .002, respectively. In conclusion, the HIV-DNA prime/HIV-MVA boost regimen elicited potent antibody and cellular immune responses with remarkable durability, and a third HIV-MVA immunization significantly boosted both antibody and cellular immune responses relative to the levels detected at the time of the third HIV-MVA, but not to higher levels than after the second HIV-MVA. [ABSTRACT FROM AUTHOR]

Background: Volunteers in phase I/II HIV vaccine trials are assumed to be at low risk of acquiring HIV infection and are expected to have normal lives in the community. However, during participation in the trials, volunteers may encounter social harm and changes in their sexual behaviours. The current study aimed to study persistence of social harm and changes in sexual practices over time among phase I/II HIV vaccine immunogenicity (HIVIS03) trial volunteers in Dar es Salaam, Tanzania. Methods and Results: A descriptive prospective cohort study was conducted among 33 out of 60 volunteers of HIVIS03 trial in Dar es Salaam, Tanzania, who had received three HIV-1 DNA injections boosted with two HIV-1 MVA doses. A structured interview was administered to collect data. Analysis was carried out using SPSS and McNemars’ chi-square (χ2) was used to test the association within-subjects. Participants reported experiencing negative comments from their colleagues about the trial; but such comments were less severe during the second follow up visits (χ2 = 8.72; P<0.001). Most of the comments were associated with discrimination (χ2 = 26.72; P<0.001), stigma (χ2 = 6.06; P<0.05), and mistrust towards the HIV vaccine trial (χ2 = 4.9; P<0.05). Having a regular sexual partner other than spouse or cohabitant declined over the two follow-up periods (χ2 = 4.45; P<0.05). Conclusion: Participants in the phase I/II HIV vaccine trial were likely to face negative comments from relatives and colleagues after the end of the trial, but those comments decreased over time. In this study, the inherent sexual practice of having extra sexual partners other than spouse declined over time. Therefore, prolonged counselling and support appears important to minimize risky sexual behaviour among volunteers after participation in HIV Vaccine trials. [ABSTRACT FROM AUTHOR]

Background. A human immunodeficiency virus (HIV) vaccine that limits disease and transmission is urgently needed. This clinical trial evaluated the safety and immunogenicity of an HIV vaccine that combines a plasmid-DNA priming vaccine and a modified vaccinia virus Ankara (MVA) boosting vaccine. Methods. Forty healthy volunteers were injected with DNA plasmids containing gp160 of HIV-1 subtypes A, B, and C; rev B; p17/p24 gagAand B, and RTmut B by use of a needle-free injection system. The vaccine was administered intradermally or intramuscularly, with or without recombinant granulocyte macrophage colony-stimulating factor, and boosted with a heterologous MVA containing env, gag, and pol of CRF01A_E. Immune responses were monitored with HIV-specific interferon (IFN)-γ and interleukin (IL)-2 ELISpot and lymphoproliferative assays (LPAs). Results. Vaccine-related adverse events were mild and tolerable. After receipt of the DNA priming vaccine, 11 (30%) of 37 vaccinees had HIV-specific IFN-γ responses. After receipt of the MVA boosting vaccine, ELISpot assays showed that 34 (92%) of 37 vaccinees had HIV-specific IFN-γ responses, 32 (86%) to Gag and 24 (65%) to Env. IFN-γ production was detected in both the CD8+ T cell compartment (5 of 9 selected vaccinees) and the CD4+ T cell compartment (9 of 9). ELISpot results showed that 25 (68%) of 37 vaccinees had a positive IL-2 response and 35 (92%) of 38 had a positive LPA response. Of 38 subjects, a total of 37 (97%) were responders. One milligram of HIV-1 DNA administered intradermally was as effective as 4mg administered intramuscularly in priming for the MVA boosting vaccine. Conclusion. This HIV-DNA priming-MVA boosting approach is safe and highly immunogenic. Trials registration. International Standard Randomised Controlled Trial number: ISRCTN32604572. [ABSTRACT FROM AUTHOR]

We evaluated antibody responses to the human immunodeficiency virus (HIV) envelope variable regions 1 and 2 (V1V2) in 29 vaccinees who had received three HIV-1 DNA immunizations and two HIV-modified vaccinia virus Ankara (MVA) boosts in the phase I/II HIVIS03 vaccine trial. Twenty vaccinees received a third HIV-MVA boost after three years in the HIVIS06 trial. IgG and IgG antibody subclasses to gp70V1V2 proteins of HIV-1 A244, CN54, Consensus C, and Case A2 were analysed using an enzyme-linked immunosorbent assay (ELISA). Cyclic V2 peptides of A244, Consensus C, and MN were used in a surface plasmon resonance (SPR) assay. Four weeks after the second HIV-MVA, anti-V1V2 IgG antibodies to A244 were detected in 97% of HIVIS03 vaccinees, in 75% three years later, and in 95% after the third HIV-MVA. Anti-CN54 V1V2 IgG was detectable in 48% four weeks after the second HIV-MVA. The SPR data supported the findings. The IgG response was predominantly IgG1. Four weeks after the second HIV-MVA, 85% of vaccinees had IgG1 antibodies to V1V2 A244, which persisted in 25% for three-years. IgG3 and IgG4 antibodies to V1V2 A244 were rare. In conclusion, the HIV-DNA/MVA vaccine regimen induced durable V1V2 IgG antibody responses in a high proportion of vaccinees. [ABSTRACT FROM AUTHOR]

The article presents a prospective cohort study on the treatment of HIV-1 infected mothers with highly active antiretroviral therapy (HAART) to prevent disease transmission to babies via breastfeeding. It notes that low postnatal transmission was identified in cases where mothers were given HAART in late pregnancy and during breastfeeding. It suggests that extended prophylaxis for mothers who do not need HAART for their own health must be evaluated and compared with infant postnatal prophylaxis.

The article investigates the possibility of reducing mother-to-child transmission (MTCT) of HIV-1 through breast feeding by prophylactic antiretroviral treatment of the infant during the breast feeding period. It highlights the results of an open-label, nonrandomized, prospective cohort study in Dar es Salaam, Tanzania. The article shows that the rates of MTCT of HIV-1 at six weeks and six months after delivery are among the lowest reported in a breast feeding population sub-Saharan Africa.

The article reports on the 1987-2000 study of prevalence and incidence trends in areas of contrasting levels of HIV-1 infections in Kagera region, Tanzania. This study aimed at assessing the extent to which decline in HIV infection prevalence reflects decline in incidence in three areas with contrasting initial exposure to the HIV epidemic. The decline in the 3 areas of differing magnitude implies that the HIV/AIDS epidemic may be arrested early without necessarily peaking to saturation levels.

Evaluates the mortality during the first 24 months after delivery in a cohort of HIV-1 infected women in Dar es Salaam, Tanzania. CD4 cell counts at enrollment; Mortality rate after delivery; Consideration of CD4 cell counts and viral load as independent risk factors for mortality.

Investigates the acceptability of HIV counseling and testing and participation in a mother-to-child HIV-1 transmission (MTCT) intervention study using antiretroviral therapy in Dar es Salaam, Tanzania. Significance of an intensive counseling in intervention programs for the prevention of MTCT; Methodology; Results and discussion.

Gives information on a population based survey of human immunodeficiency virus (HIV) infection in northwestern Tanzania. Information on community supported activities which have been initiated due to the prevalence of HIV; Methods used in the survey; Discussion on the survey.

Presents letters to the editor related to HIV clinical trials. Information on the phase III trial initiated in Thailand; Plan by the U.S. National Institute of Health, regarding vaccine trials.