Experiences of Social Harm and Changes in Sexual Practices among Volunteers Who Had Completed a Phase I/II HIV Vaccine Trial Employing HIV-1 DNA Priming and HIV-1 MVA Boosting in Dar es Salaam, Tanzania

Tarimo, Edith A. M.; Munseri, Patricia; Aboud, Said; Bakari, Muhammad; Mhalu, Fred; Sandström, Eric

doi:10.1371/journal.pone.0090938

Cited by 12 publications

(16 citation statements)

References 17 publications

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“…Various UIVs have been developed using several vaccine forms based on the combination of multiple antigens or epitopes, including recombinant subunit vaccines, DNA vaccines, and virus-vectored vaccines. In many cases, the immunization strategy of DNA prime-virus-vectored vaccine boosts was preferred because it induced a strong immune response (65,66). More importantly, the NP-based DNA prime-adenovirus boosting strategy significantly improves the NP-induced cross-protective effect (30).…”

Section: Discussionmentioning

confidence: 99%

“…In addition, UIVs containing influenza virus HA, M1, and/or NP provided effective cross-protection against a lethal challenge of influenza virus (38,(44)(45)(46)(47). Jeon, Ben-Yedidia, and Arnon (48) fused the oligonucleotides coding for three epitopes, HA 91-108 (B-cell epitope), NP [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69] (Th-cell epitope), and NP 147-158 (CD8 ϩ T-cell epitope), of influenza virus in tandem with the flagellin protein of Salmonella. Mucosal immunization with the fusion vaccine protected BALB/c mice against influenza virus of a different subtype.…”

mentioning

confidence: 99%

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Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

Wang

Deng

et al. 2015

Clin Vaccine Immunol

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bThe conventional hemagglutinin (HA)-and neuraminidase (NA)-based influenza vaccines need to be updated most years and are ineffective if the glycoprotein HA of the vaccine strains is a mismatch with that of the epidemic strain. Universal vaccines targeting conserved viral components might provide cross-protection and thus complement and improve conventional vaccines. In this study, we generated DNA plasmids and recombinant vaccinia viruses expressing the conserved proteins nucleoprotein (NP), polymerase basic 1 (PB1), and matrix 1 (M1) from influenza virus strain A/Beijing/30/95 (H3N2). BALB/c mice were immunized intramuscularly with a single vaccine based on NP, PB1, or M1 alone or a combination vaccine based on all three antigens and were then challenged with lethal doses of the heterologous influenza virus strain A/PR/8/34 (H1N1). Vaccines based on NP, PB1, and M1 provided complete or partial protection against challenge with 1.7 50% lethal dose (LD 50 ) of PR8 in mice. Of the three antigens, NP-based vaccines induced protection against 5 LD 50 and 10 LD 50 and thus exhibited the greatest protective effect. Universal influenza vaccines based on the combination of NP, PB1, and M1 induced a strong immune response and thus might be an alternative approach to addressing future influenza virus pandemics.T he conventional influenza vaccines that are available currently to prevent seasonal flu outbreaks depend mainly on the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA) (1, 2). However, HA-and NA-based conventional influenza vaccines sometimes fail to prevent flu epidemics because the HA and/or NA in the vaccine strains is a mismatch with that in circulating virus strains (3-7). Universal influenza vaccines (UIVs) that induce effective and long-term cross-protection and address the risk of mismatch may overcome the shortcomings of conventional influenza vaccines. Therefore, the development of a UIV capable of inducing long-term immunity and cross-protection remains a priority in influenza vaccine research (8).Influenza viruses are classified as type A, B, or C based on their nucleoprotein (NP) and matrix protein (M). Among the three subtypes, influenza A virus has been the target of UIVs, because the diverse influenza A strains frequently trigger influenza epidemics and pandemics. A previous study indicated that humans mount a good response to the highly conserved internal proteins NP, M1, and polymerase basic 1 (PB1) of influenza A virus (9); therefore, these highly conserved influenza A virus antigens are the basis of UIVs. Multiple studies have investigated the potential of NP (10-13), matrix protein 1 (M1) (14-17), and ion channel (M2, mainly M2e) (18-27) as alternative vaccine antigens for the prevention of seasonal and pandemic flu outbreaks. PB1 has also shown protective potential but requires further investigation for inclusion in UIVs. Košík et al. (28) constructed a DNA vaccine based on PB1, which provided some protective immunity in a mouse model. We previously constructed DNA vaccines ...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

Wang

Deng

et al. 2015

Clin Vaccine Immunol

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“…The reason for this high sexual impulse is different between males and females [ 36 ] and may be attributed to physiological factors. Despite risky sexual practices due to their young age as reported by the informants in the current study, the behavior could be changed if appropriate safer sex education is provided as reported in the previous studies [ 28 , 29 ]. Unprotected sexual practices among informants could have been caused by the attitudes and perceptions towards condoms use [ 37 , 38 ].…”

Section: Discussionmentioning

confidence: 88%

“…The reported changes in sexual behavior and practice because of participation in the HIV vaccine trial implies that the HIV vaccine trial interventions were useful. This might be due to the effectiveness of the educational seminars and training on safer sex practice which brought about the changes in sexual behavior [ 28 ]. The reported improved communication among spouses is one of the factors that strengthen marital relationships in our study.…”

Section: Discussionmentioning

confidence: 99%

“…Effective training before, during, and after the trial is required for the participants to reduce risky sexual behavior. For example, a phase I/II HIV vaccine trial (HIVIS 03) in Dar es Salaam, Tanzania reported a reduction in risky sexual behavior in most of the participants after frequent training sessions and prolonged counseling and support during the trial [ 28 ]. However, some volunteers engaged in unprotected sexual practices despite the frequent education and counseling sessions provided during the trial period.…”

Section: Introductionmentioning

confidence: 99%

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Sexual Behaviours and Practices before and after Phase I/II HIV Vaccine Trial: A Qualitative Study among Volunteers in Dar es Salaam Tanzania

Iseselo

Tarimo

Sandström

et al. 2020

IJERPH

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There is limited information about sexual behavior among volunteers who participated in phase I/II human immunodeficiency virus (HIV) vaccine trial. This article describes the sexual behavior, practices before, and after participation in phase I/II HIV vaccine trial in Dar es Salaam, Tanzania. We conducted a qualitative descriptive study involving volunteers who participated in the phase I/II vaccine trial between 2007 and 2010. Purposeful sampling was used to recruit potential informants. Twenty-four in-depth interviews were conducted. The audio-recorded interviews were transcribed verbatim and analyzed using a thematic content analysis approach. The findings revealed that before participation in the HIV vaccine trial, informants were engaging in unprotected multiple sexual relationships. After the completion of the HIV vaccine trial, informants reported strengthened marital relationships, increased understanding of safer sexual practices, and HIV testing. However, the informants reported challenges regarding vaccine-induced seropositivity that adversely affected their sexual and marital relationships. Some informants re-engaged in risky sexual practices because they perceived the experimental vaccine was protective. The informants suggested having continued interventions within the community to enhance safer sexual practices. Participation in phase I/II HIV vaccine trials may positively and negatively influence changes in volunteers’ sexual behaviors and practices. The trial interventions appear to improve compliance with safer sexual practices. However, the reported vaccine-induced seropositivity and the perception that experimental vaccines are protective need further appropriate interventions.

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How Biomedical HIV Prevention Trials Incorporate Behavioral and Social Sciences Research: A Typology of Approaches

et al. 2018

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In the field of biomedical HIV prevention, researchers have meaningfully incorporated behavioral and social sciences research (BSSR) into numerous clinical trials, though the timing and degree of integration have been highly variable. The literature offers few frameworks that systematically characterize these collaborations. To fill this gap, we developed a typology of BSSR approaches within biomedical HIV prevention research. Focusing on trials that had safety and/or efficacy endpoints, we identified five approaches for combining BSSR and clinical research: formative, embedded, parallel, explanatory, and implications. We describe each approach and provide illustrative examples. By offering a shared vocabulary for distinguishing the timing and design of collaborative BSSR and clinical research, this typology can facilitate greater transparency in collaborators’ expectations and responsibilities, and help collaborators address challenges likely to be associated with such interdisciplinary research. Electronic supplementary material The online version of this article (10.1007/s10461-018-2358-0) contains supplementary material, which is available to authorized users.

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Experiences of Social Harm and Changes in Sexual Practices among Volunteers Who Had Completed a Phase I/II HIV Vaccine Trial Employing HIV-1 DNA Priming and HIV-1 MVA Boosting in Dar es Salaam, Tanzania

Cited by 12 publications

References 17 publications

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

Protective Efficacy of the Conserved NP, PB1, and M1 Proteins as Immunogens in DNA- and Vaccinia Virus-Based Universal Influenza A Virus Vaccines in Mice

Sexual Behaviours and Practices before and after Phase I/II HIV Vaccine Trial: A Qualitative Study among Volunteers in Dar es Salaam Tanzania

How Biomedical HIV Prevention Trials Incorporate Behavioral and Social Sciences Research: A Typology of Approaches

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