scholarly journals Immunogenicity of a Live-Attenuated Dengue Vaccine Using a Heterologous Prime-Boost Strategy in a Phase 1 Randomized Clinical Trial

2020 ◽  
Author(s):  
Leyi Lin ◽  
Michael A Koren ◽  
Kristopher M Paolino ◽  
Kenneth H Eckels ◽  
Rafael De La Barrera ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Phase 1 ◽  
Vaccination Strategy ◽  
Neutralizing Antibody ◽  
Dengue Vaccine ◽  
Serious Adverse Events ◽  
Live Attenuated Vaccine ◽  
Antibody Titers ◽  
Global Health Problem

Abstract Background Dengue is a global health problem and the development of a tetravalent dengue vaccine with durable protection is a high priority. A heterologous prime-boost strategy has the advantage of eliciting immune responses through different mechanisms and therefore may be superior to homologous prime-boost strategies for generating durable tetravalent immunity. Methods In this phase 1 first-in-human heterologous prime-boost study, 80 volunteers were assigned to 4 groups and received a tetravalent dengue virus (DENV-1–4) purified inactivated vaccine (TDENV-PIV) with alum adjuvant and a tetravalent dengue virus (DENV-1–4) live attenuated vaccine (TDENV-LAV) in different orders and dosing schedules (28 or 180 days apart). Results All vaccination regimens had acceptable safety profiles and there were no vaccine-related serious adverse events. TDEN-PIV followed by TDEN-LAV induced higher neutralizing antibody titers and a higher rate of tetravalent seroconversions compared to TDEN-LAV followed by TDEN-PIV. Both TDEN-PIV followed by TDEN-LAV groups demonstrated 100% tetravalent seroconversion 28 days following the booster dose, which was maintained for most of these subjects through the day 180 measurement. Conclusions A heterologous prime-boost vaccination strategy for dengue merits additional evaluation for safety, immunogenicity, and potential for clinical benefit. Clinical Trials Registration NCT02239614.

scholarly journals Pre-vaccination Frequency of Circulatory Tfh is associated with Robust Immune Response to TV003 Dengue Vaccine

2021 ◽  
Author(s):  
Abdullah M Izmirly ◽  
Adam-Nicolas Pelletier ◽  
Jennifer Connors ◽  
Bhavani Taramangalam ◽  
Sawsan O. Alturki ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Design ◽  
Neutralizing Antibody ◽  
Dengue Vaccine ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Tetravalent Vaccine ◽  
Immunological Mechanisms

AbstractIt has been estimated that more than 390 million people are infected with Dengue virus every year; around 96 millions of these infections result in clinical pathologies. To date, there is only one licensed viral vector-based Dengue virus vaccine CYD-TDV approved for use in dengue endemic areas. While initially approved for administration independent of serostatus, the current guidance only recommends the use of this vaccine for seropositive individuals. Therefore, there is a critical need for investigating the influence of Dengue virus serostatus and immunological mechanisms that influence vaccine outcome. Here, we provide comprehensive evaluation of sero-status and host immune factors that correlate with robust immune responses to a Dengue virus vector based tetravalent vaccine (TV003) in a Phase II clinical cohort of human participants. We observed that sero-positive individuals demonstrate a much stronger immune response to the TV003 vaccine. Our multi-layered immune profiling revealed that sero-positive subjects have increased baseline/pre-vaccination frequencies of circulating T follicular helper (cTfh) cells and the Tfh related chemokine CXCL13/BLC. Importantly, this baseline/pre-vaccination cTfh profile correlated with the vaccinees’ ability to launch neutralizing antibody response against all four sero-types of Dengue virus, an important endpoint for Dengue vaccine clinical trials. Overall, we provide novel insights into the favorable cTfh related immune status that persists in Dengue virus sero-positive individuals that correlate with their ability to mount robust vaccine specific immune responses. Such detailed interrogation of cTfh cell biology in the context of clinical vaccinology will help uncover mechanisms and targets for favorable immuno-modulatory agents.Author summaryDengue virus (DENV) is a worldwide threat that causes significant health and economic burden. Currently, there are several challenges in the development of a DENV vaccine including the existence of four different serotypes all; capable of causing disease and antibody dependent enhancement (ADE). For complete protection, a vaccine must be able to generate neutralizing antibodies against all 4 serotypes to avoid ADE. Currently, there is one licensed DENV vaccine, CYD-TDV (DENGVAXIATM). However, this vaccine is only efficacious in protecting against severe disease in DENV seropositive individuals therefore serostatus effect must be further studied for optimal vaccine design. A subset of CD4+ T cells called T-follicular helper (Tfh) cells have been well known to play a major role in aiding high affinity antibody production. Therefore, we chose to look at subsets of Tfh and the cytokines they produce in human blood that can serve as biomarkers for effective vaccine design. We found that DENV sero-positive participants had increased pre-vaccination frequencies of Tfh cells and higher levels of the Tfh related chemokine CXCL13/BLC that plays a role in directing antigen-specific responses. This pre-vaccination Tfh profile and CXCL13/BLC are then correlated positively with the vaccinees’ ability to produce neutralizing antibody against all four sero-types (breadth of the Response) of DENV, an important goal for all DENV vaccine trials.

scholarly journals Long-term Safety and Immunogenicity of a Tetravalent Dengue Vaccine Candidate in Children and Adults: A Randomized, Placebo-Controlled, Phase 2 Study

2020 ◽  
Author(s):  
Chukiat Sirivichayakul ◽  
Elizabeth A Barranco-Santana ◽  
Inés Esquilín Rivera ◽  
Jennifer Kilbury ◽  
Marsha Raanan ◽  
...  
Keyword(s):  
Vaccine Candidate ◽  
Controlled Trial ◽  
Natural Infection ◽  
Neutralizing Antibody ◽  
Healthy Children ◽  
Phase 2 ◽  
Dengue Vaccine ◽  
Serious Adverse Events ◽  
Antibody Titers

Abstract Background We report long-term safety and immunogenicity of Takeda’s tetravalent dengue vaccine candidate (TAK-003) in healthy children and adults living in dengue-endemic areas in Puerto Rico, Columbia, Singapore, and Thailand. Methods In part 1 of this phase 2, randomized, placebo-controlled trial we sequentially enrolled 1.5–45 year olds (n = 148) into 4 age-descending groups, randomized 2:1 to receive 2 doses of TAK-003 or placebo 90 days apart. In part 2, 1–11 year olds (n = 212) were enrolled and randomized 3:1 to TAK-003 or placebo groups. We assessed neutralizing antibody titers for the 4 dengue serotypes (DENV) up to month 36 in part 1, and symptomatic dengue and serious adverse events (SAEs) up to month 36 in both parts. Results At month 36, seropositivity rates were 97.3%, 98.7%, 88.0% and 56.0% for DENV-1, -2, -3 and -4, respectively. Seropositivity rates varied significantly for DENV-4 according to serostatus at baseline (89.5% in seropositives versus 21.6% in seronegatives). No vaccine-related SAEs were reported. Conclusions The trial demonstrated persistence of neutralizing antibody titers against TAK-003 over 3 years in children and adults living in dengue-endemic countries, with limited contribution from natural infection. TAK-003 was well tolerated. Clinical Trials Registration NCT01511250

scholarly journals Two Complex, Adenovirus-Based Vaccines That Together Induce Immune Responses to All Four Dengue Virus Serotypes

2006 ◽  
Vol 14 (2) ◽  
pp. 182-189 ◽  
Author(s):  
David H. Holman ◽  
Danher Wang ◽  
Kanakatte Raviprakash ◽  
Nicholas U. Raja ◽  
Min Luo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Development ◽  
De Novo ◽  
Natural Infection ◽  
Hemorrhagic Fever ◽  
Virus Infections ◽  
Dengue Vaccine ◽  
Membrane Antigens ◽  
Dengue Virus Serotypes

ABSTRACT Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.

scholarly journals Immune responses to SARS-CoV-2 infection in hospitalized pediatric and adult patients

2020 ◽  
Vol 12 (564) ◽  
pp. eabd5487 ◽  
Author(s):  
Carl A. Pierce ◽  
Paula Preston-Hurlburt ◽  
Yile Dai ◽  
Clare Burn Aschner ◽  
Natalia Cheshenko ◽  
...  
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Pediatric Patients ◽  
Neutralizing Antibody ◽  
Children And Youth ◽  
Spike Protein ◽  
Serum Concentrations ◽  
Antiviral Immune Response ◽  
Antibody Titers ◽  
Ifn Γ

Children and youth infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have milder disease than do adults, and even among those with the recently described multisystem inflammatory syndrome, mortality is rare. The reasons for the differences in clinical manifestations are unknown but suggest that age-dependent factors may modulate the antiviral immune response. We compared cytokine, humoral, and cellular immune responses in pediatric (children and youth, age <24 years) (n = 65) and adult (n = 60) patients with coronavirus disease 2019 (COVID-19) at a metropolitan hospital system in New York City. The pediatric patients had a shorter length of stay, decreased requirement for mechanical ventilation, and lower mortality compared to adults. The serum concentrations of interleukin-17A (IL-17A) and interferon-γ (IFN-γ), but not tumor necrosis factor–α (TNF-α) or IL-6, were inversely related to age. Adults mounted a more robust T cell response to the viral spike protein compared to pediatric patients as evidenced by increased expression of CD25+ on CD4+ T cells and the frequency of IFN-γ+ CD4+ T cells. Moreover, serum neutralizing antibody titers and antibody-dependent cellular phagocytosis were higher in adults compared to pediatric patients with COVID-19. The neutralizing antibody titer correlated positively with age and negatively with IL-17A and IFN-γ serum concentrations. There were no differences in anti-spike protein antibody titers to other human coronaviruses. Together, these findings demonstrate that the poor outcome in hospitalized adults with COVID-19 compared to children may not be attributable to a failure to generate adaptive immune responses.

scholarly journals Effect of HIV Envelope Vaccination on the Subsequent Antibody Response to HIV Infection

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Zanele Ditse ◽  
Nonhlanhla N. Mkhize ◽  
Michael Yin ◽  
Michael Keefer ◽  
David C. Montefiori ◽  
...  
Keyword(s):  
Immune Responses ◽  
Hiv Infection ◽  
South African ◽  
Phase 1 ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Tier 2 ◽  
Subtype C ◽  
Hiv Envelope ◽  
Hiv 1

ABSTRACT Analysis of breakthrough HIV-1 infections could elucidate whether prior vaccination primes relevant immune responses. Here, we measured HIV-specific antibody responses in 14 South African volunteers who acquired HIV infection after participating in phase 1/2 trials of envelope-containing immunogens. Serum samples were collected annually following HIV-1 infection from participants in trials HVTN 073 (subtype C, DNA/MVA, phase 1 trial, n = 1), HVTN 086 (subtype C, DNA/MVA/gp140 protein, phase 1 trial, n = 2), and HVTN 204 (multisubtype, DNA/adenovirus serotype 5 [Ad5], phase 2 trial, n = 7) and 4 placebo recipients. Binding and neutralizing antibody responses to Env proteins and peptides were determined pre- and post-HIV infection using an enzyme-linked immunosorbent assay and the TZM-bl cell neutralization assay, respectively. HIV-infected South African individuals served as unvaccinated controls. Binding antibodies to gp41, V3, V2, the membrane-proximal external region (MPER), and the CD4 binding site were detected from the first year of HIV-1 subtype C infection, and the levels were similar in vaccinated and placebo recipients. Neutralizing antibody responses against tier 1A viruses were detected in all participants, with the highest titers being to a subtype C virus, MW965.26. No responses were observed just prior to infection, indicating that vaccine-primed HIV-specific antibodies had waned. Sporadic neutralization activity against tier 2 isolates was observed after 2 to 3 years of HIV infection, but these responses were similar in the vaccinated and placebo groups as well as the unvaccinated controls. Our data suggest that prior vaccination with these immunogens did not alter the antibody responses to HIV-1 infection, nor did it accelerate the development of HIV neutralization breadth. IMPORTANCE There is a wealth of information on HIV-specific vaccine-induced immune responses among HIV-uninfected participants; however, data on immune responses among participants who acquire HIV after vaccination are limited. Here we show that HIV-specific binding antibody responses in individuals with breakthrough HIV infections were not affected by prior vaccination with HIV envelope-containing immunogens. We also found that these vectored vaccines did not prime tier 2 virus-neutralizing antibody responses, which are thought to be required for prevention against HIV acquisition, or accelerate the development of neutralization breadth. Although this study is limited, such studies can provide insights into whether vaccine-elicited antibody responses are boosted by HIV infection to acquire broader neutralizing activity, which may help to identify antigens relevant to the design of more effective vaccines.

scholarly journals Navigating the Quagmire: Comparison and Interpretation of COVID-19 Vaccine Phase 1/2 Clinical Trials

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 746
Author(s):  
Luca Tudor Giurgea ◽  
Matthew James Memoli
Keyword(s):  
Adverse Events ◽  
Protective Efficacy ◽  
Phase 1 ◽  
Phase 3 ◽  
Serious Adverse Events ◽  
Safety Studies ◽  
Antibody Titers ◽  
Public Health Strategies

Vaccines against Coronavirus Disease 2019 Originated-19) have been developed with unprecedented rapidity, many utilizing novel strategies. As of November 2020, a series of publications have outlined the results of phase 1/2 studies of nine different vaccines planned to move forward to phase 3 trials. The results are encouraging, demonstrating a paucity of severe or serious adverse events and robust induction of antibody titers. Determination of the vaccine candidates with the highest protective efficacy and best adverse event profiles will be essential in refining public health strategies. However, differences in study design and reporting of data make comparisons of existing phase 1/2 studies difficult. With respect to safety, studies have variable follow-up times and may use different definitions for adverse events. Immunogenicity outcomes are even more inconsistent, with variations in timepoints and critical differences in the types of antibodies studied as well as methodological differences in assays. Furthermore, the correlates of protection in COVID-19 are not known. Harmonization of phase 3 trial designs and use of objective and meaningful clinical outcomes will be crucial in streamlining future global responses to the pandemic.

scholarly journals Statistical Approach To Estimate Vaccinia-Specific Neutralizing Antibody Titers Using a High-Throughput Assay

2009 ◽  
Vol 16 (8) ◽  
pp. 1105-1112 ◽  
Author(s):  
Richard Kennedy ◽  
V. Shane Pankratz ◽  
Eric Swanson ◽  
David Watson ◽  
Hana Golding ◽  
...  
Keyword(s):  
Immune Responses ◽  
Vaccinia Virus ◽  
High Throughput ◽  
Large Scale ◽  
Statistical Approach ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Virus Neutralization Assay ◽  
Antibody Titers ◽  
High Throughput Assay

ABSTRACT Because of the bioterrorism threat posed by agents such as variola virus, considerable time, resources, and effort have been devoted to biodefense preparation. One avenue of this research has been the development of rapid, sensitive, high-throughput assays to validate immune responses to poxviruses. Here we describe the adaptation of a β-galactosidase reporter-based vaccinia virus neutralization assay to large-scale use in a study that included over 1,000 subjects. We also describe the statistical methods involved in analyzing the large quantity of data generated. The assay and its associated methods should prove useful tools in monitoring immune responses to next-generation smallpox vaccines, studying poxvirus immunity, and evaluating therapeutic agents such as vaccinia virus immune globulin.

scholarly journals IMMUNO-COV v2.0: Development and Validation of a High-Throughput Clinical Assay for Measuring SARS-CoV-2-Neutralizing Antibody Titers

mSphere ◽  
2021 ◽  
Author(s):  
Rianna Vandergaast ◽  
Timothy Carey ◽  
Samantha Reiter ◽  
Chase Lathrum ◽  
Patrycja Lech ◽  
...  
Keyword(s):  
Immune Responses ◽  
High Throughput ◽  
Causative Agent ◽  
Neutralizing Antibody ◽  
Clinical Assay ◽  
Antibody Titers ◽  
Development And Validation

Since its emergence at the end of 2019, SARS-CoV-2, the causative agent of COVID-19, has caused over 100 million infections and 2.4 million deaths worldwide. Recently, countries have begun administering approved COVID-19 vaccines, which elicit strong immune responses and prevent disease in most vaccinated individuals.

scholarly journals Safety and immunogenicity trial of an inactivated SARS-CoV-2 vaccine-BBV152: a phase 1, double-blind, randomised control trial

2020 ◽  
Author(s):  
Raches Ella ◽  
Krishna Mohan ◽  
Harsh Jogdand ◽  
Sai Prasad ◽  
Siddharth Reddy ◽  
...  
Keyword(s):  
Phase 1 ◽  
Neutralizing Antibody ◽  
Cold Chain ◽  
Wild Type Virus ◽  
Randomised Control Trial ◽  
Enzyme Linked Immunosorbent Assay ◽  
Double Blind ◽  
Efficacy Trials ◽  
National Immunization ◽  
Antibody Titers

Background: BBV152 is a whole-virion inactivated SARS-CoV-2 vaccine formulated with a TLR 7/8 agonist molecule adsorbed to alum (Algel-IMDG). Methods We conducted a double-blind randomized controlled phase 1 clinical trial to evaluate the safety and immunogenicity of BBV152. A total of 375 participants were randomized equally to receive three vaccine formulations (n=100 each) prepared with 3 μg with Algel-IMDG, 6 μg with Algel-IMDG, and 6 μg with Algel, and an Algel only control arm (n=75). Vaccines were administered on a two-dose intramuscular accelerated schedule on day 0 (baseline) and day 14. The primary outcomes were reactogenicity and safety. The secondary outcomes were immunogenicity based on the anti-IgG S1 response (detected with an enzyme-linked immunosorbent assay [ELISA] and wild-type virus neutralization [microneutralization and plaque reduction neutralization assays]). Cell-mediated responses were also evaluated. Results: Reactogenicity was absent in the majority of participants, with mild events. The majority of adverse events were mild and were resolved. One serious adverse event was reported, which was found to be unrelated to vaccination. All three vaccine formulations resulted in robust immune responses comparable to a panel of convalescent serum. No significant differences were observed between the 3-μg and 6-μg Algel-IMDG groups. Neutralizing responses to homologous and heterologous SARS-CoV-2 strains were detected in all vaccinated individuals. Cell-mediated responses were biased to a Th-1 phenotype. Conclusions BBV152 induced binding and neutralising antibody responses and with the inclusion of the Algel-IMDG adjuvant, this is the first inactivated SARS-CoV-2 vaccine that has been reported to induce a Th1-biased response. Vaccine-induced neutralizing antibody titers were reported with two divergent SARS-CoV-2 strains. BBV152 is stored between 2°C and 8°C, which is compatible with all national immunization program cold chain requirements. Both Algel-IMDG formulations were selected for the phase 2 immunogenicity trials. Further efficacy trials are underway.

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