1
|
Tatoud R, Brander C, Hwang C, Kennelly J, Lu S, O’Neil K, Safrit JT, Benhayoun I, Firmat J, Barriere N. Biotech's role in advancing HIV vaccine development. Emerg Microbes Infect 2024; 13:2384460. [PMID: 39042015 PMCID: PMC11321102 DOI: 10.1080/22221751.2024.2384460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/17/2024] [Accepted: 07/19/2024] [Indexed: 07/24/2024]
Abstract
HIV vaccine development has been hindered by significant challenges over four decades. Despite persistent efforts, all efficacy trials to date have yielded disappointing results. This has pushed the field back to the discovery phase and created uncertainty about the future involvement of large pharmaceutical companies. Currently, the HIV vaccine landscape is dominated by startup biotech firms, which face a complex array of obstacles. These include evolving HIV prevention methods, waning interest in vaccine research, and difficulties securing sustainable funding. This viewpoint explores the challenges faced by these biotech companies and the support mechanisms necessary for their continued involvement in HIV vaccine development. By leveraging insights from both pharmaceutical and biotech sectors, we propose a multi-faceted approach that includes enhanced communication, fostering innovation, and implementing strategic funding models.
Collapse
Affiliation(s)
| | | | | | | | - Shan Lu
- Worcester HIV Vaccine, Worcester, MA, USA
| | | | | | | | | | | |
Collapse
|
2
|
Kaur A, Vaccari M. Exploring HIV Vaccine Progress in the Pre-Clinical and Clinical Setting: From History to Future Prospects. Viruses 2024; 16:368. [PMID: 38543734 PMCID: PMC10974975 DOI: 10.3390/v16030368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/08/2024] [Accepted: 02/21/2024] [Indexed: 04/01/2024] Open
Abstract
The human immunodeficiency virus (HIV) continues to pose a significant global health challenge, with millions of people affected and new cases emerging each year. While various treatment and prevention methods exist, including antiretroviral therapy and non-vaccine approaches, developing an effective vaccine remains the most crucial and cost-effective solution to combating the HIV epidemic. Despite significant advancements in HIV research, the HIV vaccine field has faced numerous challenges, and only one clinical trial has demonstrated a modest level of efficacy. This review delves into the history of HIV vaccines and the current efforts in HIV prevention, emphasizing pre-clinical vaccine development using the non-human primate model (NHP) of HIV infection. NHP models offer valuable insights into potential preventive strategies for combating HIV, and they play a vital role in informing and guiding the development of novel vaccine candidates before they can proceed to human clinical trials.
Collapse
Affiliation(s)
- Amitinder Kaur
- Division of Immunology, Tulane National Primate Research Center, Covington, LA 70433, USA;
- School of Medicine, Tulane University, New Orleans, LA 70112, USA
| | - Monica Vaccari
- Division of Immunology, Tulane National Primate Research Center, Covington, LA 70433, USA;
- School of Medicine, Tulane University, New Orleans, LA 70112, USA
| |
Collapse
|
3
|
Ndung'u T. The KT Jeang retrovirology prize 2023: Thumbi Ndung'u. Retrovirology 2023; 20:17. [PMID: 37848918 PMCID: PMC10583396 DOI: 10.1186/s12977-023-00632-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2023] Open
Affiliation(s)
- Thumbi Ndung'u
- Africa Health Research Institute, Durban, South Africa.
- HIV Pathogenesis Programme, The Doris Duke Medical Research Institute, University of KwaZulu-Natal, Durban, South Africa.
- Ragon Institute of MGH, MIT and Harvard University, Cambridge, MA, USA.
- Division of Infection and Immunity, University College London, London, UK.
| |
Collapse
|
4
|
Desrosiers RC. The Failure of AIDS Vaccine Efficacy Trials: Where to Go from Here. J Virol 2023; 97:e0021123. [PMID: 36916947 PMCID: PMC10062124 DOI: 10.1128/jvi.00211-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
The seven AIDS vaccine efficacy trials have yielded extremely disappointing results at great expense. Greater stringency is needed for government support of AIDS vaccine efficacy trials.
Collapse
|
5
|
Klasse PJ, Moore JP. Reappraising the Value of HIV-1 Vaccine Correlates of Protection Analyses. J Virol 2022; 96:e0003422. [PMID: 35384694 PMCID: PMC9044961 DOI: 10.1128/jvi.00034-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2022] [Indexed: 01/09/2023] Open
Abstract
With the much-debated exception of the modestly reduced acquisition reported for the RV144 efficacy trial, HIV-1 vaccines have not protected humans against infection, and a vaccine of similar design to that tested in RV144 was not protective in a later trial, HVTN 702. Similar vaccine regimens have also not consistently protected nonhuman primates (NHPs) against viral acquisition. Conversely, experimental vaccines of different designs have protected macaques from viral challenges but then failed to protect humans, while many other HIV-1 vaccine candidates have not protected NHPs. While efficacy varies more in NHPs than humans, vaccines have failed to protect in the most stringent NHP model. Intense investigations have aimed to identify correlates of protection (CoPs), even in the absence of net protection. Unvaccinated animals and humans vary vastly in their susceptibility to infection and in their innate and adaptive responses to the vaccines; hence, merely statistical associations with factors that do not protect are easily found. Systems biological analyses, including artificial intelligence, have identified numerous candidate CoPs but with no clear consistency within or between species. Proposed CoPs sometimes have only tenuous mechanistic connections to immune protection. In contrast, neutralizing antibodies (NAbs) are a central mechanistic CoP for vaccines that succeed against other viruses, including SARS-CoV-2. No HIV-1 vaccine candidate has yet elicited potent and broadly active NAbs in NHPs or humans, but narrow-specificity NAbs against the HIV-1 isolate corresponding to the immunogen do protect against infection by the autologous virus. Here, we analyze why so many HIV-1 vaccines have failed, summarize the outcomes of vaccination in NHPs and humans, and discuss the value and pitfalls of hunting for CoPs other than NAbs. We contrast the failure to find a consistent CoP for HIV-1 vaccines with the identification of NAbs as the principal CoP for SARS-CoV-2.
Collapse
Affiliation(s)
- P. J. Klasse
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York, USA
| | - John P. Moore
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York, USA
| |
Collapse
|
6
|
Barin F, Stefic K. [Protection against HIV-1 infection: "It's the neutralizing antibody, stupid!"]. Med Sci (Paris) 2021; 37:1178-1179. [PMID: 34928225 DOI: 10.1051/medsci/2021175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Francis Barin
- Inserm U1259, université de Tours, 10 boulevard Tonnellé, 37004 Tours, France
| | - Karl Stefic
- Inserm U1259, université de Tours, 10 boulevard Tonnellé, 37004 Tours, France - Laboratoire de virologie et CNR VIH-laboratoire associé, CHU Bretonneau, 2 boulevard Tonnellé, 37004 Tours, France
| |
Collapse
|
7
|
Jones LD, Moody MA, Thompson AB. Innovations in HIV-1 Vaccine Design. Clin Ther 2020; 42:499-514. [PMID: 32035643 PMCID: PMC7102617 DOI: 10.1016/j.clinthera.2020.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/20/2019] [Accepted: 01/16/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE The field of HIV-1 vaccinology has evolved during the last 30 years from the first viral vector HIV gene insert constructs to vaccination regimens using a myriad of strategies. These strategies now include germline-targeting, lineage-based, and structure-guided immunogen design. This narrative review outlines the historical context of HIV vaccinology and subsequently highlights the scientific discoveries during the last 6 years that promise to propel the field forward. METHODS We conducted a search of 2 electronic databases, PubMed and EMBASE, for experimental studies that involved new HIV immunogen designs between 2013 and 2019. During the title and abstract reviews, publications were excluded if they were written in language other than English and/or were a letter to the editor, a commentary, or a conference-only presentation. We then used ClinicalTrials.gov to identify completed and ongoing clinical trials using these strategies. FINDINGS The HIV vaccinology field has undergone periods of significant growth during the last 3 decades. Findings elucidated in preclinical studies have revealed the importance of the interaction between the cellular and humoral immune system. As a result, several new rationally designed vaccine strategies have been developed and explored in the last 6 years, including native-like envelope trimers, nanoparticle, and mRNA vaccine design strategies among others. Several of these strategies have shown enough promise in animal models to progress toward first-in-human Phase I clinical trials. IMPLICATIONS Rapid developments in preclinical and early-phase clinical studies suggest that a tolerable and effective HIV vaccine may be on the horizon.
Collapse
Affiliation(s)
- Letitia D Jones
- Duke Human Vaccine Institute, Duke University School of Medicine, Durham, NC, USA
| | - M Anthony Moody
- Duke University School of Medicine and Duke Human Vaccine Institute, Durham, NC, USA
| | - Amelia B Thompson
- Duke University School of Medicine and Duke Human Vaccine Institute, Durham, NC, USA.
| |
Collapse
|
8
|
Van Regenmortel MH. Truth in science and in molecular recognition, post‐truth in human affairs. J Mol Recognit 2019; 33:e2827. [DOI: 10.1002/jmr.2827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
9
|
Rahman MA, Robert-Guroff M. Accelerating HIV vaccine development using non-human primate models. Expert Rev Vaccines 2018; 18:61-73. [PMID: 30526159 DOI: 10.1080/14760584.2019.1557521] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION The search for a preventative HIV vaccine is ongoing after three decades of research. Contributions of non-human primate (NHP) models to this research are irrefutable, however interpreting data obtained for translation to humans has been problematic. As knowledge concerning NHP models has accumulated, their utility and value in assessing immunogenicity and efficacy of novel vaccines have become apparent. NHP models have become a critical component of vaccine design. AREAS COVERED Beginning with early vaccine studies, we trace the development and evolution of NHP models concurrent with changes in HIV vaccine concepts and in response to their ability to predict clinical trial efficacy. The value of NHP studies in guiding vaccine design is highlighted along with their importance in opening new areas of investigation and facilitating movement of promising approaches into the clinic. EXPERT COMMENTARY Due to their close relatedness to humans, NHPs are an excellent choice for immunogenicity studies. The ability of NHP models to predict clinical efficacy has improved with the introduction of low-dose challenge viruses and recognition of confounding variables in study outcomes. Use of NHP models has opened new research areas with outstanding potential for generating vaccine efficacy against HIV and other infectious agents.
Collapse
Affiliation(s)
- Mohammad Arif Rahman
- a Vaccine Branch, Center for Cancer Research , National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
| | - Marjorie Robert-Guroff
- a Vaccine Branch, Center for Cancer Research , National Cancer Institute, National Institutes of Health , Bethesda , MD , USA
| |
Collapse
|
10
|
Robinson HL. HIV/AIDS Vaccines: 2018. Clin Pharmacol Ther 2018; 104:1062-1073. [PMID: 30099743 PMCID: PMC6282490 DOI: 10.1002/cpt.1208] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 07/30/2018] [Indexed: 12/17/2022]
Abstract
Human immunodeficiency virus (HIV) has infected 76 million people and killed an estimated 35 million. During its 40-year history, remarkable progress has been made on antiretroviral drugs. Progress toward a vaccine has also been made, although this has yet to deliver a licensed product. In 2007, I wrote a review, HIV AIDS Vaccines: 2007. This review, HIV AIDS Vaccines: 2018, focuses on the progress in the past 11 years. I begin with key challenges for the development of an AIDS vaccine and the lessons learned from the six completed efficacy trials, only one of which has met with some success.
Collapse
|
11
|
HIV-vaccines: lessons learned and the way forward. ASIAN BIOMED 2018. [DOI: 10.2478/abm-2010-0090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
A safe and efficacious preventive HIV vaccine, as part of a comprehensive prevention program, remains among the highest public health priorities. It would be the best tool that could reduce the spread of HIV significantly in the long run. Current AIDS vaccine candidates are unable to induce neutralizing antibodies against primary HIV isolates or only to a very limited and narrow extent, representing a major obstacle in the development of an efficacious HIV vaccine. Clinical efforts have mainly focused on T-cell vaccines such as DNA and various recombinant vectors alone or in prime-boost regimens. The Merck Ad5 vaccine not only failed to show efficacy but also was associated with increased risk of HIV acquisition in vaccinees in a Phase IIb trial. While gp120 alone was not efficacious, the ALVAC prime and gp120 boost regimen showed 31% efficacy in a Phase III trial in Thailand. These contrasting results illustrate the limitations of available laboratory assays to assess the vaccine-induced immune responses and the lack of understanding of immune correlates of protection. Efforts should therefore focus on developing vaccine candidates inducing broadly neutralizing antibodies. Similarly, new vector strategies such as replicating vectors should be explored to induce strong and broad T-cell responses in the systemic and mucosal compartments. Innovation in immune assay development and testing algorithms is critically needed. The standardization of more relevant and predictive non-human primate models for immunogenicity and efficacy studies will contribute to better and faster vaccine assessment. HIV vaccine development requires innovative ideas and a sustained long-term commitment of the scientific community, civil society, politicians, and donors and participants for clinical research.
Collapse
|
12
|
Abstract
INTRODUCTION Despite many recent advances in the HIV prevention landscape, an effective vaccine remains the most promising tool to end the HIV-1 pandemic. Areas covered: This review summarizes past HIV vaccine efficacy trials and current vaccine strategies as well as new approaches about to move into first-in-human trials. Expert opinion: Despite many setbacks in early HIV vaccine efficacy trials, the success of RV144 has provided the glimmer of hope necessary to invigorate the vaccine field, and has led to the development of a large number of vaccine strategies aiming at inducing an array of different immune responses. The follow-up pox-protein trials, developed to replicate and enhance the polyfunctional antibody responses induced by the RV144 regimen, are already reaching efficacy trials, while a large body of work providing a more complete understanding of the development of broadly neutralizing antibodies is now being translated into immunogen design using several different strategies. T-cell based vaccines, fallen out of favor after Ad5-based trials showed increased infection rates in Ad5 seropositive vaccine recipients, are experiencing a comeback based in part on the promising results from non-human primate challenge studies using rhCMV-based immunogens. This diverse array of vaccine candidates may finally allow us to identify a broadly effective HIV vaccine able to contain the epidemic.
Collapse
Affiliation(s)
- Kristen W Cohen
- a Vaccine and Infectious Disease Division , Fred Hutchinson Cancer Research Center , Seattle , WA , USA
| | - Nicole Frahm
- a Vaccine and Infectious Disease Division , Fred Hutchinson Cancer Research Center , Seattle , WA , USA.,b Department of Global Health , University of Washington , Seattle , WA , USA
| |
Collapse
|
13
|
Van Regenmortel MHV. Structure-Based Reverse Vaccinology Failed in the Case of HIV Because it Disregarded Accepted Immunological Theory. Int J Mol Sci 2016; 17:E1591. [PMID: 27657055 PMCID: PMC5037856 DOI: 10.3390/ijms17091591] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 08/30/2016] [Accepted: 09/07/2016] [Indexed: 12/14/2022] Open
Abstract
Two types of reverse vaccinology (RV) should be distinguished: genome-based RV for bacterial vaccines and structure-based RV for viral vaccines. Structure-based RV consists in trying to generate a vaccine by first determining the crystallographic structure of a complex between a viral epitope and a neutralizing monoclonal antibody (nMab) and then reconstructing the epitope by reverse molecular engineering outside the context of the native viral protein. It is based on the unwarranted assumption that the epitope designed to fit the nMab will have acquired the immunogenic capacity to elicit a polyclonal antibody response with the same protective capacity as the nMab. After more than a decade of intensive research using this type of RV, this approach has failed to deliver an effective, preventive HIV-1 vaccine. The structure and dynamics of different types of HIV-1 epitopes and of paratopes are described. The rational design of an anti-HIV-1 vaccine is shown to be a misnomer since investigators who claim that they design a vaccine are actually only improving the antigenic binding capacity of one epitope with respect to only one paratope and not the immunogenic capacity of an epitope to elicit neutralizing antibodies. Because of the degeneracy of the immune system and the polyspecificity of antibodies, each epitope studied by the structure-based RV procedure is only one of the many epitopes that the particular nMab is able to recognize and there is no reason to assume that this nMab must have been elicited by this one epitope of known structure. Recent evidence is presented that the trimeric Env spikes of the virus possess such an enormous plasticity and intrinsic structural flexibility that it is it extremely difficult to determine which Env regions are the best candidate vaccine immunogens most likely to elicit protective antibodies.
Collapse
Affiliation(s)
- Marc H V Van Regenmortel
- UMR 7242 Biotechnologie et Signalisation Cellulaire, Université de Strasbourg-CNRS, 300, Boulevard Sébastien Brant, CS 10413, 67412 Illkirch Cedex, France.
| |
Collapse
|
14
|
Ohata PJ, Avihingsanon A, Ubolyam S, Putcharoen O, Kerr SJ, Volnysanne A, Nanthapisal K, Ruengpayyathip C, Bunupuradah T, Prasitsuebsai W, Kukanok S, Do T, Landolt NK, Ruxrungtham K, Phanuphak P. Updates on HIV treatment and prevention from Asia's HIV symposium: the 18th Bangkok International Symposium on HIV Medicine. Future Virol 2016. [DOI: 10.2217/fvl-2016-0017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The 18th Bangkok International Symposium on HIV Medicine, Queen Sirikit National Convention Centre, Bangkok, Thailand, 13–15 January 2016 Consistent with HIV-NAT's mission, quality training is provided to many professional healthcare workers in the region by taking the latest knowledge from research and presenting it locally at the Bangkok International Symposium of HIV Medicine. The symposium is offered every third week of January for 3 days. Some of the plenary session content is presented below.
Collapse
Affiliation(s)
- Pirapon J Ohata
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Anchalee Avihingsanon
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
- Division of Allergy & Clinical Immunology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
| | - Sasiwimol Ubolyam
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Opass Putcharoen
- Division of Infectious Diseases, Department of Medicine, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
| | - Stephen J Kerr
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Alain Volnysanne
- EATG in Europe (European AIDS Treatment group), Place Raymond Blyckaerts, 13, B-1050 Brussels, Belgium
| | - Kesdao Nanthapisal
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Chavalun Ruengpayyathip
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Torsak Bunupuradah
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Wasana Prasitsuebsai
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Sivaporn Kukanok
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Tanya Do
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Nadia K Landolt
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | - Kiat Ruxrungtham
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
- Division of Allergy & Clinical Immunology, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Rama IV Road, Pathumwan, Bangkok 10330, Thailand
| | - Praphan Phanuphak
- HIV-NAT, Thai Red Cross – AIDS Research Centre, 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
- Thai Red Cross – AIDS Research Centre (TRCARC), 104 Ratchadamri Rd, Pathumwan, Bangkok 10330, Thailand
| | | |
Collapse
|
15
|
Lo YR, Chu C, Ananworanich J, Excler JL, Tucker JD. Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward. AIDS Patient Care STDS 2015; 29:389-99. [PMID: 26061668 DOI: 10.1089/apc.2014.0348] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders.
Collapse
Affiliation(s)
- Ying-Ru Lo
- HIV, Hepatitis and STI Unit, World Health Organization, Regional Office for the Western Pacific, Manila, The Philippines
| | - Carissa Chu
- University of California San Francisco School of Medicine, San Francisco, California
- University of North Carolina Project-China, Guangzhou, P.R. China
| | - Jintanat Ananworanich
- US Military HIV Research Program, Bethesda, Maryland
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Jean-Louis Excler
- US Military HIV Research Program, Bethesda, Maryland
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland
| | - Joseph D. Tucker
- University of North Carolina Project-China, Guangzhou, P.R. China
- Institute of Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| |
Collapse
|
16
|
Esparza J. A New Scientific Paradigm may be Needed to Finally Develop an HIV Vaccine. Front Immunol 2015; 6:124. [PMID: 25852692 PMCID: PMC4364287 DOI: 10.3389/fimmu.2015.00124] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/06/2015] [Indexed: 12/13/2022] Open
Abstract
The bulk of current HIV vaccine research is conducted within the infectious disease paradigm that has been very successful in developing vaccines against many other viral diseases. Different HIV vaccine concepts, based on the induction of neutralizing antibodies and/or cell mediated immunity, have been developed and clinically tested over the last 30 years, resulting in a few small successes and many disappointments. As new scientific knowledge is obtained, HIV vaccine concepts are constantly modified with the hope that the newly introduced tweaks (or paradigm drifts) will provide the solution to one of the most difficult challenges that modern biomedical research is confronting. Efficacy trials have been critical in guiding HIV vaccine development. However, from the five phase III efficacy trials conducted to date, only one (RV144) resulted in modest efficacy. The results from RV144 were surprising in many ways, including the identified putative correlates of protection (or risk), which did not include neutralizing antibodies or cytotoxic T-cells. The solution to the HIV vaccine challenge may very well come from approaches based on the current paradigm. However, at the same time, out-of-the-paradigm ideas should be systematically explored to complement the current efforts. New mechanisms are needed to identify and support the innovative research that will hopefully accelerate the development of an urgently needed HIV vaccine.
Collapse
Affiliation(s)
- José Esparza
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
17
|
Abstract
Purpose of review To summarize the role of adjuvants in eliciting desirable antibody responses against HIV-1 with particular emphasis on both historical context and recent developments. Recent findings Increased understanding of the role of pattern recognition receptors such as Toll-like receptors in recruiting and directing the immune system has increased the variety of adjuvant formulations being tested in animal models and humans. Across all vaccine platforms, adjuvant formulations have been shown to enhance desirable immune responses such as higher antibody titers and increased functional activity. Although no vaccine formulation has yet succeeded in eliciting broad neutralizing antibodies against HIV-1, the ability of adjuvants to direct the immune response to immunogens suggests they will be critically important in any successful HIV-1 vaccine. Summary The parallel development of adjuvants along with better HIV-1 immunogens will be needed for a successful AIDS vaccine. Additional comparative testing will be required to determine the optimal adjuvant and immunogen regimen that can elicit antibody responses capable of blocking HIV-1 transmission.
Collapse
|
18
|
Abstract
Although some success was achieved in recent years in HIV prevention, an effective vaccine remains the means with the most potential of curtailing HIV-1 infections worldwide. Despite multiple failed attempts, a recent HIV vaccine regimen demonstrated modest protection from infection. Although the protective efficacy in this trial was not sufficient to warrant licensure, it spurred renewed optimism in the field and has provided valuable insights for improving future vaccine designs. This review summarizes the pertinent details of vaccine development and discusses ways the field is moving forward to develop a vaccine to prevent HIV infection and disease progression.
Collapse
Affiliation(s)
- Paul Goepfert
- Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, 908, 20th Street South, CCB 328, Birmingham, AL 35294, USA.
| | - Anju Bansal
- Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, 845, 19th Street South, BBRB 557, Birmingham, AL 35294, USA
| |
Collapse
|
19
|
Phase I/II randomized trial of safety and immunogenicity of LIPO-5 alone, ALVAC-HIV (vCP1452) alone, and ALVAC-HIV (vCP1452) prime/LIPO-5 boost in healthy, HIV-1-uninfected adult participants. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1589-99. [PMID: 25253665 DOI: 10.1128/cvi.00450-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Finding an effective human immunodeficiency virus type 1 (HIV-1) vaccine remains a major global health priority. In a phase I/II, placebo-controlled trial, healthy, HIV-1-negative adults were randomized to receive one of 5 vaccine regimens: LIPO-5 (combination of 5 lipopeptides) alone (250 μg), ALVAC-HIV (vCP1452) alone, or 3 groups of ALVAC-HIV (vCP1452) followed by ALVAC-HIV (vCP1452) plus LIPO-5 (250, 750, and 2,500 μg). Only 73/174 participants (42%) received all four vaccinations due to a study halt related to myelitis. There were no significant differences in systemic reactions between groups or in local reactogenicity between groups receiving ALVAC-HIV (vCP1452). Significant differences in local reactogenicity occurred between groups receiving LIPO-5 (P ≤ 0.05). Gag and Env antibodies were undetectable by ELISA 2 weeks after the fourth vaccination for all but one recipient. Antibodies to Gag and Env were present in 32% and 24% of recipients of ALVAC-HIV (vCP1452) alone and in 47% and 35% of ALVAC-HIV (vCP1452)+LIPO recipients, respectively. Coadministration of LIPO-5 did not significantly increase the response rate compared to ALVAC-HIV (vCP1452) alone, nor was there a significant relationship between dose and antibody responses among ALVAC-HIV (vCP1452)+LIPO groups. Over 90% of study participants had no positive gamma interferon (IFN-γ) enzyme-linked immunosorbent spot assay (ELISpot) responses to any peptide pool at any time point. The study was halted due to a case of myelitis possibly related to the LIPO-5 vaccine; this case of myelitis remains an isolated event. In general, there was no appreciable cell-mediated immunity detected in response to the vaccines used in this study, and antibody responses were limited. The clinical trial is registered on ClinicalTrials.gov with registry number NCT00076063.
Collapse
|
20
|
O'Connell RJ, Kim JH, Excler JL. The HIV-1 gp120 V1V2 loop: structure, function and importance for vaccine development. Expert Rev Vaccines 2014; 13:1489-500. [PMID: 25163695 DOI: 10.1586/14760584.2014.951335] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Although the second variable loop (V2) of the HIV-1 gp120 envelope glycoprotein shows substantial sequence diversity between strains, its functional importance imposes critical conservation of structure, and within particular microdomains, of sequence. V2 influences HIV-1 viral entry by contributing to trimer stabilization and co-receptor binding. It is one of 4 key domains targeted by the broadly neutralizing antibodies that arise during HIV-1 infection. HIV-1 uses V1V2 sequence variation and glycosylation to escape neutralizing antibody. In the Thai Phase III HIV-1 vaccine trial, RV144, vaccine-induced IgG against V1V2 inversely correlated with the risk of HIV-1 acquisition, and HIV-1 strains infecting RV144 vaccine recipients differed from those infecting placebo recipients in the V2 domain. Similarly, non-human primate challenge studies demonstrated an inverse correlation between vaccine-induced anti-V2 responses and simian immunodeficiency virus acquisition. We hypothesize that increased magnitude, frequency and duration of vaccine-induced anti-V2 antibody responses should improve efficacy afforded by pox-protein prime-boost HIV vaccine strategies.
Collapse
Affiliation(s)
- Robert J O'Connell
- Armed Forces Research Institute of Medical Sciences (AFRIMS), 315/6 Rajvithi Road, Bangkok 10400, Thailand
| | | | | |
Collapse
|
21
|
Esparza J, Van Regenmortel MHV. More Surprises in the Development of an HIV Vaccine. Front Immunol 2014; 5:329. [PMID: 25071786 PMCID: PMC4095567 DOI: 10.3389/fimmu.2014.00329] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 06/29/2014] [Indexed: 01/16/2023] Open
Affiliation(s)
- José Esparza
- Institute of Human Virology, University of Maryland School of Medicine , Baltimore, MD , USA
| | - Marc H V Van Regenmortel
- CNRS, UMR7242-Institut de Recherche de l'Ecole de Biotechnologie de Strasbourg (IREBS), Université de Strasbourg , Illkirch-Graffenstaden , France
| |
Collapse
|
22
|
Nonneutralizing functional antibodies: a new "old" paradigm for HIV vaccines. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1023-36. [PMID: 24920599 DOI: 10.1128/cvi.00230-14] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Animal and human data from various viral infections and vaccine studies suggest that nonneutralizing antibodies (nNAb) without neutralizing activity in vitro may play an important role in protection against viral infection in vivo. This was illustrated by the recent human immunodeficiency virus (HIV) RV144 vaccine efficacy trial, which demonstrated that HIV-specific IgG-mediated nNAb directed against the V2 loop of HIV type 1 envelope (Env) were inversely correlated with risk for HIV acquisition, while Env-specific plasma IgA-mediated antibodies were directly correlated with risk. However, tier 1 NAb in the subset of responders with a low level of plasma Env-specific IgA correlated with decreased risk. Nonhuman primate simian immunodeficiency virus (SIV) and simian-human immunodeficiency virus (SHIV) challenge studies suggest that Env-mediated antibodies are essential and sufficient for protection. A comparison of immune responses generated in human efficacy trials reveals subtle differences in the fine specificities of the antibody responses, in particular in HIV-specific IgG subclasses. The underlying mechanisms that may have contributed to protection against HIV acquisition in humans, although not fully understood, are possibly mediated by antibody-dependent cell-mediated cytotoxicity (ADCC) and/or other nonneutralizing humoral effector functions, such as antibody-mediated phagocytosis. The presence of such functional nNAb in mucosal tissues and cervico-vaginal and rectal secretions challenges the paradigm that NAb are the predominant immune response conferring protection, although this does not negate the desirability of evoking neutralizing antibodies through vaccination. Instead, NAb and nNAb should be looked upon as complementary or synergistic humoral effector functions. Several HIV vaccine clinical trials to study these antibody responses in various prime-boost modalities in the systemic and mucosal compartments are ongoing. The induction of high-frequency HIV-specific functional nNAb at high titers may represent an attractive hypothesis-testing strategy in future HIV vaccine efficacy trials.
Collapse
|
23
|
Rao M, Peachman KK, Kim J, Gao G, Alving CR, Michael NL, Rao VB. HIV-1 variable loop 2 and its importance in HIV-1 infection and vaccine development. Curr HIV Res 2014; 11:427-38. [PMID: 24191938 DOI: 10.2174/1570162x113116660064] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 05/24/2013] [Accepted: 06/13/2013] [Indexed: 12/30/2022]
Abstract
A vaccine that can prevent the transmission of HIV-1 at the site of exposure to the host is one of the best hopes to control the HIV-1 pandemic. The trimeric envelope spike consisting of heterodimers, gp120 and gp41, is essential for virus entry and thus has been a key target for HIV-1 vaccine development. However, it has been extremely difficult to identify the types of antibodies required to block the transmission of various HIV-1 strains and the immunogens that can elicit such antibodies due to the high genetic diversity of the HIV-1 envelope. The modest efficacy of the gp120 HIV-1 vaccine used in the RV144 Thai trial, including the studies on the immune correlates of protection, and the discovery of vaccine-induced immune responses to certain signature regions of the envelope have shown that the gp120 variable loop 2 (V2) is an important region. Since there is evidence that the V2 region interacts with the integrin α4β7 receptor of the host cell, and that this interaction might be important for virus capture, induction of antibodies against V2 loop could be postulated as one of the mechanisms to prevent the acquisition of HIV-1. Immunogens that can induce these antibodies should therefore be taken into consideration when designing HIV-1 vaccine formulations.
Collapse
Affiliation(s)
- Mangala Rao
- Laboratory of Adjuvant and Antigen Research, USMHRP at the Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Rm 2A08, Sliver Spring, MD 20910, USA.
| | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
PURPOSE OF REVIEW With multiple HIV vaccine candidates suitable for efficacy evaluation in a rapidly changing HIV prevention landscape, innovative HIV vaccine trial design research is much needed to optimally utilize resources by building on lessons learned from past HIV vaccine efficacy trials. RECENT FINDINGS Several recent articles propose new vaccine efficacy trial design strategies tailored to the emerging needs in HIV vaccine evaluation. These include a focus on efficacy evaluation proximal to the vaccination series; more intensive interim monitoring for potential harm, nonefficacy and high efficacy of the vaccine; simultaneous evaluation of multiple vaccine regimens with a shared placebo group; designs that include pilot immunogenicity studies of putative immune correlates to expedite their evaluation; as well as designs tailored to evaluate vaccine efficacy in the context of partially effective nonvaccine prevention modalities. SUMMARY A more rapid evaluation of multiple vaccine candidates is possible. Weaker vaccines can be weeded out quickly. Pilot studies can be done during the trial to prepare for a timely immune correlates assessment. Evidence that emerges regarding the efficacy of nonvaccine prevention modalities will have important implications for future trial designs.
Collapse
|
25
|
Madhavi V, Kent SJ, Stratov I. HIV-specific antibody-dependent cellular cytotoxicity: a novel vaccine modality. Expert Rev Clin Immunol 2014; 8:767-74. [DOI: 10.1586/eci.12.74] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
26
|
Korber B. Building on the past to define an efficient path to an HIV vaccine. Expert Rev Vaccines 2014; 10:929-31. [DOI: 10.1586/erv.11.81] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
27
|
Esparza J. Solid vaccine protection against SIV in rhesus monkeys provides proof-of-concept for further evaluation of a novel HIV vaccine approach in humans. Expert Rev Vaccines 2014; 11:539-42. [DOI: 10.1586/erv.12.21] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
28
|
van Griensven F, Phanuphak N, Srithanaviboonchai K. Biomedical HIV prevention research and epidemic control in Thailand: two sides of the same coin. Sex Health 2014; 11:180-99. [PMID: 25000363 DOI: 10.1071/sh13119] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 03/10/2014] [Indexed: 02/04/2023]
Abstract
For a country with a moderate adult HIV prevalence of just over 1% in 2012, Thailand is widely perceived as having made some extraordinary contributions to the global management of the HIV/AIDS pandemic. It has been promoted as a model of effective HIV control and applauded for its leadership in providing access to antiretroviral treatment. Thailand has also received international recognition for its contribution to biomedical HIV prevention research, which is generally perceived as exceptional. In this paper, Thailand's global role model function as an example of effective HIV/AIDS control and high-quality biomedical HIV prevention research is re-evaluated against the background of currently available data and more recent insights. The results indicate that Thailand's initial response in raising the level of the political significance of HIV/AIDS was indeed extraordinary, which probably prevented a much larger epidemic from occurring. However, this response transpired in unusual extraconstitutional circumstances and its effectiveness declined once the country returned to political normalcy. Available data confirm the country's more than exceptional contribution to biomedical HIV prevention research. Thailand has made a huge contribution to the global management and control of the HIV/AIDS pandemic.
Collapse
Affiliation(s)
- Frits van Griensven
- Thai Red Cross AIDS Research Center, 104 Rajadamri Road, Patumwan, Bangkok 10330, Thailand
| | - Nittaya Phanuphak
- Thai Red Cross AIDS Research Center, 104 Rajadamri Road, Patumwan, Bangkok 10330, Thailand
| | - Kriengkrai Srithanaviboonchai
- Research Institute for Health Sciences and Faculty of Medicine, Chiang Mai University, 110 Intavaroros Road, Sriphum, Muang Chiang Mai 50200, Thailand
| |
Collapse
|
29
|
Bailey TC, Sugarman J. Social justice and HIV vaccine research in the age of pre-exposure prophylaxis and treatment as prevention. Curr HIV Res 2013; 11:473-80. [PMID: 24033297 PMCID: PMC4084567 DOI: 10.2174/1570162x113116660054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 06/05/2013] [Accepted: 07/11/2013] [Indexed: 11/22/2022]
Abstract
The advent of pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP) as means of HIV prevention raises issues of justice concerning how most fairly and equitably to apportion resources in support of the burgeoning variety of established HIV treatment and prevention measures and further HIV research, including HIV vaccine research. We apply contemporary approaches to social justice to assess the ethical justification for allocating resources in support of HIV vaccine research given competing priorities to support broad implementation of HIV treatment and prevention measures, including TasP and PrEP. We argue that there is prima facie reason to believe that a safe and effective preventive HIV vaccine would offer a distinct set of ethically significant benefits not provided by current HIV treatment or prevention methods. It is thereby possible to justify continued support for HIV vaccine research despite tension with priorities for treatment, prevention, and other research. We then consider a counter-argument to such a justification based on the uncertainty of successfully developing a safe and effective preventive HIV vaccine. Finally, we discuss how HIV vaccine research might now be ethically designed and conducted given the new preventive options of TasP and PrEP, focusing on the ethically appropriate standard of prevention for HIV vaccine trials.
Collapse
Affiliation(s)
| | - Jeremy Sugarman
- Johns Hopkins Berman Institute of Bioethics and Division of Infectious Diseases, 1809 Ashland Avenue, Baltimore, MD, 21205, USA.
| |
Collapse
|
30
|
Abstract
Antiviral vaccines have been the most successful biomedical intervention for preventing epidemic viral disease. Vaccination for smallpox in humans and rinderpest in cattle was the basis for disease eradication, and recent progress in polio eradication is promising. Although early vaccines were developed empirically by passage in live animals or eggs, more recent vaccines have been developed because of the advent of new technologies, particularly cell culture and molecular biology. Recent technological advances in gene delivery and expression, nanoparticles, protein manufacturing, and adjuvants have created the potential for new vaccine platforms that may provide solutions for vaccines against viral pathogens for which no interventions currently exist. In addition, the technological convergence of human monoclonal antibody isolation, structural biology, and high-throughput sequencing is providing new opportunities for atomic-level immunogen design. Selection of human monoclonal antibodies can identify immunodominant antigenic sites associated with neutralization and provide reagents for stabilizing and solving the structure of viral surface proteins. Understanding the structural basis for neutralization can guide selection of vaccine targets. Deep sequencing of the antibody repertoire and defining the ontogeny of the desired antibody responses can reveal the junctional recombination and somatic mutation requirements for B-cell recognition and affinity maturation. Collectively, this information will provide new strategic approaches for selecting vaccine antigens, formulations, and regimens. Moreover, it creates the potential for rational vaccine design and establishing a catalogue of vaccine technology platforms that would be effective against any given family or class of viral pathogens and improve our readiness to address new emerging viral threats.
Collapse
Affiliation(s)
- Barney S Graham
- NIAID, NIH, Vaccine Research Center, Bethesda, MD 20892-3017, USA.
| |
Collapse
|
31
|
Liu Z, Wang S, Zhang Q, Tian M, Hou J, Wang R, Liu C, Ji X, Liu Y, Shao Y. Deletion of C7L and K1L genes leads to significantly decreased virulence of recombinant vaccinia virus TianTan. PLoS One 2013; 8:e68115. [PMID: 23840887 PMCID: PMC3698190 DOI: 10.1371/journal.pone.0068115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 05/24/2013] [Indexed: 11/19/2022] Open
Abstract
The vaccinia virus TianTan (VTT) has been modified as an HIV vaccine vector in China and has shown excellent performance in immunogenicity and safety. However, its adverse effects in immunosuppressed individuals warrant the search for a safer vector in the following clinic trails. In this study, we deleted the C7L and K1L genes of VTT and constructed six recombinant vaccinia strains VTT△C7L, VTT△K1L, VTT△C7LK1L, VTKgpe△C7L, VTKgpe△K1L and VTT△C7LK1L-gag. The pathogenicity and immunogenicity of these recombinants were evaluated in mouse and rabbit models. Comparing to parental VTT, VTT△C7L and VTT△K1L showed significantly decreased replication capability in CEF, Vero, BHK-21 and HeLa cell lines. In particular, replication of VTT△C7LK1L decreased more than 10-fold in all four cell lines. The virulence of all these mutants were decreased in BALB/c mouse and rabbit models; VTT△C7LK1L once again showed the greatest attenuation, having resulted in no evident damage in mice and erythema of only 0.4 cm diameter in rabbits, compared to 1.48 cm for VTT. VTKgpe△C7L, VTKgpe△K1L and VTT△C7LK1L-gag elicited as strong cellular and humoral responses against HIV genes as did VTKgpe, while humoral immune response against the vaccinia itself was reduced by 4-8-fold. These data show that deletion of C7L and K1L genes leads to significantly decreased virulence without compromising animal host immunogenicity, and may thus be key to creating a more safe and effective HIV vaccine vector.
Collapse
Affiliation(s)
- Zheng Liu
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Shuhui Wang
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Qicheng Zhang
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
- Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory of Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, China
| | - Meijuan Tian
- Division of Infectious Diseases & HIV Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
| | - Jue Hou
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Rongmin Wang
- Clinical Laboratory, Zhaoyuan CDC, Zhaoyuan, China
| | - Chang Liu
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Xu Ji
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Ying Liu
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| | - Yiming Shao
- Division of Research on Virology and Immunology, State Key Laboratory for Infectious Disease Prevention and Control, National Center for AIDS/STD Control and Prevention (NCAIDS), China CDC, Beijing, China
| |
Collapse
|
32
|
A brief history of the global effort to develop a preventive HIV vaccine. Vaccine 2013; 31:3502-18. [PMID: 23707164 DOI: 10.1016/j.vaccine.2013.05.018] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Revised: 05/01/2013] [Accepted: 05/07/2013] [Indexed: 01/09/2023]
Abstract
Soon after HIV was discovered as the cause of AIDS in 1983-1984, there was an expectation that a preventive vaccine would be rapidly developed. In trying to achieve that goal, three successive scientific paradigms have been explored: induction of neutralizing antibodies, induction of cell mediated immunity, and exploration of combination approaches and novel concepts. Although major progress has been made in understanding the scientific basis for HIV vaccine development, efficacy trials have been critical in moving the field forward. In 2009, the field was reinvigorated with the modest results obtained from the RV144 trial conducted in Thailand. Here, we review those vaccine development efforts, with an emphasis on events that occurred during the earlier years. The goal is to provide younger generations of scientists with information and inspiration to continue the search for an HIV vaccine.
Collapse
|
33
|
Moyle PM, Toth I. Modern subunit vaccines: development, components, and research opportunities. ChemMedChem 2013; 8:360-76. [PMID: 23316023 DOI: 10.1002/cmdc.201200487] [Citation(s) in RCA: 312] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 12/08/2012] [Indexed: 12/11/2022]
Abstract
Traditional vaccines, based on the administration of killed or attenuated microorganisms, have proven to be among the most effective methods for disease prevention. Safety issues related to administering these complex mixtures, however, prevent their universal application. Through identification of the microbial components responsible for protective immunity, vaccine formulations can be simplified, enabling molecular-level vaccine characterization, improved safety profiles, prospects to develop new high-priority vaccines (e.g. for HIV, tuberculosis, and malaria), and the opportunity for extensive vaccine component optimization. This subunit approach, however, comes at the expense of decreased immunity, requiring the addition of immunostimulatory agents (adjuvants). As few adjuvants are currently used in licensed vaccines, adjuvant development represents an exciting area for medicinal chemists to play a role in the future of vaccine development. In addition, immune responses can be further customized though optimization of delivery systems, tuning the size of particulate vaccines, targeting specific cells of the immune system (e.g. dendritic cells), and adding components to aid vaccine efficacy in whole immunized populations (e.g. promiscuous T-helper epitopes). Herein we review the current state of the art and future direction in subunit vaccine development, with a focus on the described components and their potential to steer the immune response toward a desired response.
Collapse
Affiliation(s)
- Peter Michael Moyle
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia.
| | | |
Collapse
|
34
|
Abstract
Two vaccine trials that were conducted 50 years apart are reviewed and compared: the 1954 field trial of the Salk inactivated polio vaccine and the RV144 HIV vaccine trial conducted in Thailand between 2003 and 2009. Despite the obvious differences in science and historical periods, several lessons were identified that could inform the future HIV vaccine effort. Those lessons are related to paradigm changes that occur when science progresses, the need to test scientific hypothesis in efficacy trials, the controversies surrounding those trials, the need for strong community and political support, the participation of government and nongovernment institutions, the balance between implementation of other preventive and therapeutic interventions, and the priority given by society to develop a vaccine. If we have the humility and courage to apply some of those lessons, we may be able accelerate the development of an urgently needed HIV vaccine.
Collapse
|
35
|
Antibodies with high avidity to the gp120 envelope protein in protection from simian immunodeficiency virus SIV(mac251) acquisition in an immunization regimen that mimics the RV-144 Thai trial. J Virol 2012; 87:1708-19. [PMID: 23175374 DOI: 10.1128/jvi.02544-12] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The recombinant canarypox vector, ALVAC-HIV, together with human immunodeficiency virus (HIV) gp120 envelope glycoprotein, has protected 31.2% of Thai individuals from HIV acquisition in the RV144 HIV vaccine trial. This outcome was unexpected, given the limited ability of the vaccine components to induce CD8(+) T-cell responses or broadly neutralizing antibodies. We vaccinated macaques with an immunization regimen intended to mimic the RV144 trial and exposed them intrarectally to a dose of the simian immunodeficiency virus SIV(mac251) that transmits few virus variants, similar to HIV transmission to humans. Vaccination induced anti-envelope antibodies in all vaccinees and CD4(+) and CD8(+) T-cell responses. Three of the 11 macaques vaccinated with ALVAC-SIV/gp120 were protected from SIV(mac251) acquisition, but the result was not significant. The remaining vaccinees were infected and progressed to disease. The magnitudes of vaccine-induced SIV(mac251)-specific T-cell responses and binding antibodies were not significantly different between protected and infected animals. However, sera from protected animals had higher avidity antibodies to gp120, recognized the variable envelope regions V1/V2, and reduced SIV(mac251) infectivity in cells that express high levels of α(4)β(7) integrins, suggesting a functional role of antibodies to V2. The current results emphasize the utility of determining the titer of repeated mucosal challenge in the preclinical evaluation of HIV vaccines.
Collapse
|
36
|
Design by trial. Nature 2012; 490:350-1. [DOI: 10.1038/490350a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
37
|
Plotkin SA, Robinson HL, Davenport MP. Mining the mechanisms of an HIV vaccine. Nat Med 2012; 18:1020-1. [PMID: 22772554 DOI: 10.1038/nm.2858] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Stanley A Plotkin
- University of Pennsylvania, Philadelphia, Pennsylvania, USA, and Vaxconsult, Doylestown, Pennsylvania, USA
| | | | | |
Collapse
|
38
|
Robb ML, Rerks-Ngarm S, Nitayaphan S, Pitisuttithum P, Kaewkungwal J, Kunasol P, Khamboonruang C, Thongcharoen P, Morgan P, Benenson M, Paris RM, Chiu J, Adams E, Francis D, Gurunathan S, Tartaglia J, Gilbert P, Stablein D, Michael NL, Kim JH. Risk behaviour and time as covariates for efficacy of the HIV vaccine regimen ALVAC-HIV (vCP1521) and AIDSVAX B/E: a post-hoc analysis of the Thai phase 3 efficacy trial RV 144. THE LANCET. INFECTIOUS DISEASES 2012; 12:531-7. [PMID: 22652344 DOI: 10.1016/s1473-3099(12)70088-9] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND The Thai phase 3 HIV vaccine trial RV 144 showed modest efficacy of a vaccine against HIV acquisition. Baseline variables of age, sex, marital status, and risk did not modify vaccine efficacy. We did a post-hoc analysis of the trial's data to investigate behavioural risk and efficacy every 6 months after vaccination. METHODS RV 144 was a randomised, multicentre, double-blind, placebo-controlled efficacy trial testing the combination of the HIV vaccines ALVAC-HIV (vCP1521) and AIDSVAX B/E to prevent HIV infection or reduce setpoint viral load. Male and female volunteers aged 18-30 years were recruited from the community. In this post-hoc analysis of the modified intention-to-treat population (16,395 participants), HIV risk behaviour was assessed with a self-administered questionnaire at the time of initial vaccination in the trial and every 6 months thereafter for 3 years. We classified participants' behaviour as low, medium, or high risk. Both the acquisition endpoint and the early viral-load endpoint were examined for interactions with risk status over time and temporal effects after vaccination. Multiple proportional hazards regression models with treatment and time-varying risk covariates were analysed. FINDINGS Risk of acquisition of HIV was low in each risk group, but 9187 (58·2%) participants reported higher-risk behaviour at least once during the study. Participants classified as high or increasing risk at least once during follow-up were compared with those who maintained low-risk or medium-risk behaviour as a time-varying covariate, and the interaction of risk status and acquisition efficacy was significant (p=0·01), with greater benefit in low-risk individuals. Vaccine efficacy seemed to peak early--cumulative vaccine efficacy was estimated to be 60·5% (95% CI 22-80) through the 12 months after initial vaccination--and declined quickly. Vaccination did not seem to affect viral load in either early or late infections. INTERPRETATION Future HIV vaccine trials should recognise potential interactions between challenge intensity and risk heterogeneity in both population and treatment effects. The regimen tested in the RV 144 phase 3 trial might benefit from extended immunisation schedules. FUNDING US Army Medical Research and Materiel Command and Division of AIDS, National Institute of Allergy and Infectious Disease, National Institutes of Health.
Collapse
Affiliation(s)
- Merlin L Robb
- US Military HIV Research Program, Division of Retrovirology, Walter Reed Army Institute of Research, Rockville, MD, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Stephens HAF. Immunogenetic surveillance of HIV/AIDS. INFECTION GENETICS AND EVOLUTION 2012; 12:1481-91. [PMID: 22575339 DOI: 10.1016/j.meegid.2012.04.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 04/05/2012] [Accepted: 04/06/2012] [Indexed: 11/28/2022]
Abstract
Evolutionary pressure by viruses is most likely responsible for the extraordinary allelic polymorphism of genes encoding class I human leukocyte antigens (HLA) and killer immunoglobulin-like receptors (KIR). Such genetic diversity has functional implications for the immune response to viruses and generates population-based variations in HLA class I allele frequencies and KIR gene profiles. The HIV-1 virus has relatively recently established itself as a major human pathogen, rapidly diversifying into a variety of phylogenetic subtypes or clades (A-G) and recombinants in different populations. HIV-1 clade C is the most common subtype in circulation accounting for 48% of all infections, followed by HIV-1 clades A and B which are responsible for 13% and 11% of infections in the current pandemic, respectively. Candidate gene studies of large cohorts of predominantly HIV-1 clade B but also clades C and A infected patients, have consistently shown significant associations between certain HLA class I alleles namely HLA-B*57, B*58, B*27, B*51 and relatively low viraemia. However, there is evidence that other associations between HLA-B*15, B*18 or B*53 and levels of HIV-1 viraemia are clade-specific. Recent genome-wide association studies of HIV-1 clade B exposed cohorts have confirmed that HLA-B, which is the most polymorphic locus in the human genome, is the major genetic locus contributing to immune control of viraemia. Moreover, the presence of natural killer cell receptors encoded by KIR-3DL1 and 3DS1 genes together with certain HLA class I alleles carrying the KIR target motif Bw4Ile80, provides an enhanced ability to control HIV-1 viraemia in some individuals. It is likely that rapid co-evolution of HIV-1 immune escape variants together with an adjustment of human immune response gene profiles has occurred in some exposed populations. Taken together, immunogenetic surveillance of HIV-1 exposed cohorts has revealed important correlates of natural immunity, which could provide a rational platform for the design and testing of future vaccines aimed at controlling the current AIDS pandemic.
Collapse
Affiliation(s)
- Henry A F Stephens
- UCL Centre for Nephrology and the Anthony Nolan Laboratories, Royal Free Hospital, Rowland Hill Street, London NW3 2PF, UK.
| |
Collapse
|
40
|
Van Regenmortel MHV. Requirements for empirical immunogenicity trials, rather than structure-based design, for developing an effective HIV vaccine. Arch Virol 2011; 157:1-20. [PMID: 22012269 PMCID: PMC7087187 DOI: 10.1007/s00705-011-1145-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 10/07/2011] [Indexed: 11/29/2022]
Abstract
The claim that it is possible to rationally design a structure-based HIV-1 vaccine is based on misconceptions regarding the nature of protein epitopes and of immunological specificity. Attempts to use reverse vaccinology to generate an HIV-1 vaccine on the basis of the structure of viral epitopes bound to monoclonal neutralizing antibodies have failed so far because it was not possible to extrapolate from an observed antigenic structure to the immunogenic structure required in a vaccine. Vaccine immunogenicity depends on numerous extrinsic factors such as the host immunoglobulin gene repertoire, the presence of various cellular and regulatory mechanisms in the immunized host and the process of antibody affinity maturation. All these factors played a role in the appearance of the neutralizing antibody used to select the epitope to be investigated as potential vaccine immunogen, but they cannot be expected to be present in identical form in the host to be vaccinated. It is possible to rationally design and optimize an epitope to fit one particular antibody molecule or to improve the paratope binding efficacy of a monoclonal antibody intended for passive immunotherapy. What is not possible is to rationally design an HIV-1 vaccine immunogen that will elicit a protective polyclonal antibody response of predetermined efficacy. An effective vaccine immunogen can only be discovered by investigating experimentally the immunogenicity of a candidate molecule and demonstrating its ability to induce a protective immune response. It cannot be discovered by determining which epitopes of an engineered antigen molecule are recognized by a neutralizing monoclonal antibody. This means that empirical immunogenicity trials rather than structural analyses of antigens offer the best hope of discovering an HIV-1 vaccine.
Collapse
Affiliation(s)
- Marc H V Van Regenmortel
- Stellenbosch Institute of Advanced Study, Wallenberg Research Center at Stellenbosch University, Stellenbosch 7600, South Africa.
| |
Collapse
|
41
|
Newman PA, Logie C, James L, Charles T, Maxwell J, Salam K, Woodford M. "Speaking the dialect": understanding public discourse in the aftermath of an HIV vaccine trial shutdown. Am J Public Health 2011; 101:1749-58. [PMID: 21778490 PMCID: PMC3154228 DOI: 10.2105/ajph.2011.300208] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2011] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We investigated how persons from key populations at higher risk of HIV exposure interpreted the process and outcomes of the Step Study HIV-1 vaccine trial, which was terminated early, and implications for willingness to participate in and community support for HIV vaccine research. METHODS We used qualitative methods and a community-based approach in 9 focus groups (n = 72) among ethnically and sexually diverse populations and 6 semistructured key informant interviews in Ontario, Canada, in 2007 to 2008. RESULTS Participants construed social meaning from complex clinical and biomedical phenomena. Social representations and mental models emerged in fears of vaccine-induced infection, conceptualizations of unfair recruitment practices and increased risk behaviors among trial participants, and questioning of informed consent. Narratives of altruism and the common good demonstrated support for future trials. CONCLUSIONS Public discourse on HIV vaccine trials is a productive means of interpreting complex clinical trial processes and outcomes in the context of existing beliefs and experiences regarding HIV vaccines, medical research, and historical disenfranchisement. Strategic engagement with social representations and mental models may promote meaningful community involvement in biomedical HIV prevention research.
Collapse
Affiliation(s)
- Peter A Newman
- Factor-Inwentash Faculty of Social Work, University of Toronto, ON, Canada.
| | | | | | | | | | | | | |
Collapse
|
42
|
Makedonas G, Betts MR. Living in a house of cards: re-evaluating CD8+ T-cell immune correlates against HIV. Immunol Rev 2011; 239:109-24. [PMID: 21198668 DOI: 10.1111/j.1600-065x.2010.00968.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Merck STEP and the Thai RV144 human immunodeficiency virus (HIV) vaccine trials confirmed that we still have a long way to go before developing a prophylactic HIV vaccine. The main issue at hand is that we have yet to identify an immunological correlate of protection against HIV. While many question the T-cell-based approach towards vaccine development, it is likely that T cells will be a necessary part of any vaccine strategy. CD8(+) T cells remain an attractive option because of their ability to specifically recognize and eliminate virally infected host cells. In this review, we recapitulate the evidence for CD8(+) T cells as an immunological correlate against HIV, but more importantly, we assess the means by which we evaluate their antiviral capacity. To achieve a breakthrough in the domain of T-cell-based HIV vaccine development, it has become abundantly clear that we must overhaul our system of immune monitoring and come up with a 'rational' tactic to evaluate the efficacy of HIV-specific CD8(+) T cells.
Collapse
|
43
|
Abstract
Acquired immune deficiency syndrome (AIDS), malaria and tuberculosis collectively cause more than five million deaths per year, but have nonetheless eluded conventional vaccine development; for this reason they represent one of the major global public health challenges as we enter the second decade of the twenty-first century. Recent trials have provided evidence that it is possible to develop vaccines that can prevent infection by human immunodeficiency virus (HIV) and malaria. Furthermore, advances in vaccinology, including novel adjuvants, prime-boost regimes and strategies for intracellular antigen presentation, have led to progress in developing a vaccine against tuberculosis. Here we discuss these advances and suggest that new tools such as systems biology and structure-based antigen design will lead to a deeper understanding of mechanisms of protection which, in turn, will lead to rational vaccine development. We also argue that new and innovative approaches to clinical trials will accelerate the availability of these vaccines.
Collapse
|
44
|
Girard MP, Osmanov S, Assossou OM, Kieny MP. Human immunodeficiency virus (HIV) immunopathogenesis and vaccine development: a review. Vaccine 2011; 29:6191-218. [PMID: 21718747 DOI: 10.1016/j.vaccine.2011.06.085] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Revised: 06/20/2011] [Accepted: 06/22/2011] [Indexed: 02/08/2023]
Abstract
The development of a safe, effective and globally affordable HIV vaccine offers the best hope for the future control of the HIV-1 pandemic. Since 1987, scores of candidate HIV-1 vaccines have been developed which elicited varying degrees of protective responses in nonhuman primate models, including DNA vaccines, subunit vaccines, live vectored recombinant vaccines and various prime-boost combinations. Four of these candidate vaccines have been tested for efficacy in human volunteers, but, to the exception of the recent RV144 Phase III trial in Thailand, which elicited a modest but statistically significant level of protection against infection, none has shown efficacy in preventing HIV-1 infection or in controlling virus replication and delaying progression of disease in humans. Protection against infection was observed in the RV144 trial, but intensive research is needed to try to understand the protective immune mechanisms at stake. Building-up on the results of the RV144 trial and deciphering what possibly are the immune correlates of protection are the top research priorities of the moment, which will certainly accelerate the development of an highly effective vaccine that could be used in conjunction with other HIV prevention and treatment strategies. This article reviews the state of the art of HIV vaccine development and discusses the formidable scientific challenges met in this endeavor, in the context of a better understanding of the immunopathogenesis of the disease.
Collapse
Affiliation(s)
- Marc P Girard
- University Paris 7, French National Academy of Medicine, 39 rue Seignemartin, FR 69008 Lyon, France.
| | | | | | | |
Collapse
|
45
|
Gilbert PB, Berger JO, Stablein D, Becker S, Essex M, Hammer SM, Kim JH, Degruttola VG. Statistical interpretation of the RV144 HIV vaccine efficacy trial in Thailand: a case study for statistical issues in efficacy trials. J Infect Dis 2011; 203:969-75. [PMID: 21402548 DOI: 10.1093/infdis/jiq152] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recently, the RV144 randomized, double-blind, efficacy trial in Thailand reported that a prime-boost human immunodeficiency virus (HIV) vaccine regimen conferred ∼30% protection against HIV acquisition. However, different analyses seemed to give conflicting results, and a heated debate ensued as scientists and the broader public struggled with their interpretation. The lack of accounting for statistical principles helped flame the debate, and we leverage these principles to provide a more scientific interpretation. We first address interpretation of frequentist results, including interpretation of P values, synthesis of results from multiple analyses (ie, intention-to-treat versus per-protocol/fully immunized), and accounting for external efficacy trials. Second, we address how Bayesian statistics, which provide clearly interpretable statements about probabilities that the vaccine efficacy takes certain values, provide more information for weighing the evidence about efficacy than do frequentist statistics alone. Third, we evaluate RV144 for completeness of end point ascertainment and integrity of blinding, necessary tasks for establishing robustly interpretable results.
Collapse
Affiliation(s)
- Peter B Gilbert
- Vaccine Infectious Disease Division, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington 98109, USA.
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Clark K, Cavicchi J, Jensen K, Fitzgerald R, Bennett A, Kowalski SP. Patent data mining: a tool for accelerating HIV vaccine innovation. Vaccine 2011; 29:4086-93. [PMID: 21496469 DOI: 10.1016/j.vaccine.2011.03.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 03/08/2011] [Accepted: 03/17/2011] [Indexed: 11/29/2022]
Abstract
Global access to advanced vaccine technologies is challenged by the interrelated components of intellectual property (IP) management strategies, technology transfer (legal and technical) capabilities and the capacity necessary for accelerating R&D, commercialization and delivery of vaccines. Due to a negative association with the management of IP, patents are often overlooked as a vast resource of freely available, information akin to scientific journals as well as business and technological information and trends fundamental for formulating policies and IP management strategies. Therefore, a fundamental step towards facilitating global vaccine access will be the assembly, organization and analysis of patent landscapes, to identify the amount of patenting, ownership (assignees) and fields of technology covered. This is critical for making informed decisions (e.g., identifying licensees, building research and product development collaborations, and ascertaining freedom to operate). Such information is of particular interest to the HIV vaccine community where the HIV Vaccine Enterprise, have voiced concern that IP rights (particularly patents and trade secrets) may prevent data and materials sharing, delaying progress in research and development of a HIV vaccine. We have compiled and analyzed a representative HIV vaccine patent landscape for a prime-boost, DNA/adenoviral vaccine platform, as an example for identifying obstacles, maximizing opportunities and making informed IP management strategy decisions towards the development and deployment of an efficacious HIV vaccine.
Collapse
Affiliation(s)
- K Clark
- PIPRA, University of California, Davis, CA 95616, USA.
| | | | | | | | | | | |
Collapse
|
47
|
Abstract
PURPOSE OF REVIEW An effective HIV vaccine is a global health priority. We describe lessons learned from four HIV vaccine trials that failed to demonstrate efficacy and one that showed modest protection as a pathway forward. RECENT FINDINGS The Merck Ad5 phase IIb T-cell vaccine failed to show efficacy and might have increased the risk of HIV acquisition in men who have sex with men. Although VaxGen gp120 alone was not efficacious in groups at high risk for HIV-1 infection, the RV144 ALVAC prime and gp120 boost regimen showed 31% efficacy in low-incidence heterosexuals. All trials demonstrated the limitations of available laboratory and animal models to assess relevant vaccine-induced immune responses and predict clinical trial outcome. Analysis of innate and adaptive responses induced in RV144 will guide future trial design. SUMMARY Future HIV vaccine trials should define the RV144 immune responses relevant to protection, improve durability and level of protection, and assess efficacy in diverse risk groups. New strategies examining heterologous vector prime-boost, universal inserts, replicating vectors, and novel protein or adjuvant immunogens should be explored to induce T-cell and antibody responses. HIV vaccine development requires innovative ideas and a sustained long-term commitment of scientists, governments, and the community.
Collapse
|
48
|
A Sequential Phase 2b Trial Design for Evaluating Vaccine Efficacy and Immune Correlates for Multiple HIV Vaccine Regimens. ACTA ACUST UNITED AC 2011. [PMID: 23181167 DOI: 10.2202/1948-4690.1037] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Five preventative HIV vaccine efficacy trials have been conducted over the last 12 years, all of which evaluated vaccine efficacy (VE) to prevent HIV infection for a single vaccine regimen versus placebo. Now that one of these trials has supported partial VE of a prime-boost vaccine regimen, there is interest in conducting efficacy trials that simultaneously evaluate multiple prime-boost vaccine regimens against a shared placebo group in the same geographic region, for accelerating the pace of vaccine development. This article proposes such a design, which has main objectives (1) to evaluate VE of each regimen versus placebo against HIV exposures occurring near the time of the immunizations; (2) to evaluate durability of VE for each vaccine regimen showing reliable evidence for positive VE; (3) to expeditiously evaluate the immune correlates of protection if any vaccine regimen shows reliable evidence for positive VE; and (4) to compare VE among the vaccine regimens. The design uses sequential monitoring for the events of vaccine harm, non-efficacy, and high efficacy, selected to weed out poor vaccines as rapidly as possible while guarding against prematurely weeding out a vaccine that does not confer efficacy until most of the immunizations are received. The evaluation of the design shows that testing multiple vaccine regimens is important for providing a well-powered assessment of the correlation of vaccine-induced immune responses with HIV infection, and is critically important for providing a reasonably powered assessment of the value of identified correlates as surrogate endpoints for HIV infection.
Collapse
|
49
|
Fuchs JD, Sobieszczyk ME, Hammer SM, Buchbinder SP. Lessons drawn from recent HIV vaccine efficacy trials. J Acquir Immune Defic Syndr 2010; 55 Suppl 2:S128-31. [PMID: 21406982 PMCID: PMC3079543 DOI: 10.1097/qai.0b013e3181fbca02] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A safe and effective HIV vaccine is needed to curtail the US and global epidemics. However, the search for one has been elusive despite more than 25 years of focused research. Results from the RV144 Thai efficacy trial have renewed hope that a vaccine may protect against HIV acquisition. We can draw several scientific and operational lessons from RV144 and other recent tests-of-concept efficacy trials. Here we describe how trial results, some unexpected, highlight the fundamental role these clinical studies play in HIV vaccine discovery. These trials also teach us that transparency in data analysis and results dissemination can yield substantial rewards and that efforts to engage communities, particularly those most heavily affected by the epidemic, are needed to augment research literacy and trial recruitment. Future efficacy trial designs may incorporate novel, partially effective prevention strategies. Although greater in size and complexity, these trials may offer unique opportunities to explore synergies with vaccines under study.
Collapse
Affiliation(s)
- Jonathan D Fuchs
- HIV Research Section, San Francisco Department of Public Health, San Francisco, CA 94102, USA.
| | | | | | | |
Collapse
|
50
|
Vaccari M, Poonam P, Franchini G. Phase III HIV vaccine trial in Thailand: a step toward a protective vaccine for HIV. Expert Rev Vaccines 2010; 9:997-1005. [PMID: 20822342 PMCID: PMC7337582 DOI: 10.1586/erv.10.104] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The large human efficacy trail in Thailand, RV144, was concluded in the summer of 2009. This is the first Phase III trial to show limited, but significant, efficacy in preventing HIV acquisition. This trial represents the first sign that a preventive vaccine for HIV may be feasible. The vaccine regimen tested in Thailand consisted of priming with a Canarypox vector carrying three synthetic HIV genes. The priming was followed by booster inoculations with two recombinant envelope proteins from HIV, clade B and E. The need to understand the role in protection from HIV acquisition of the new responses, induced by this vaccine combination, has brought together many researchers with the common goal of improving the development of a safe and effective vaccine for HIV.
Collapse
Affiliation(s)
- Monica Vaccari
- Animal Models and Retroviral Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Poonam Poonam
- Animal Models and Retroviral Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Genoveffa Franchini
- Animal Models and Retroviral Vaccine Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|