Prime-boost vaccination regimens with INO-4800 and INO-4802 augment and broaden immune responses against SARS-CoV-2 in nonhuman primates

The enhanced transmissibility and immune evasion associated with emerging SARS-CoV-2 variants demands the development of next-generation vaccines capable of inducing superior protection amid a shifting pandemic landscape. Since a portion of the global population harbors some level of immunity from vaccines based on the original Wuhan-Hu-1 SARS-CoV-2 sequence or natural infection, an important question going forward is whether this immunity can be boosted by next-generation vaccines that target emerging variants while simultaneously maintaining long-term protection against existing strains. Here, we evaluated the immunogenicity of INO-4800, our synthetic DNA vaccine candidate for COVID-19 currently in clinical evaluation, and INO-4802, a next-generation DNA vaccine designed to broadly target emerging SARS-CoV-2 variants, as booster vaccines in nonhuman primates. Rhesus macaques primed over one year prior with the first-generation INO-4800 vaccine were boosted with either INO-4800 or INO-4802 in homologous or heterologous prime-boost regimens. Both boosting schedules led to an expansion of antibody responses which were characterized by improved neutralizing and ACE2 blocking activity across wild-type SARS-CoV-2 as well as multiple variants of concern. These data illustrate the durability of immunity following vaccination with INO-4800 and additionally support the use of either INO-4800 or INO-4802 in prime-boost regimens.

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Prime-Boost Vaccination Using Chemokine-Fused gp120 DNA and HIV Envelope Peptides Activates Both Immediate and Long-Term Memory Cellular Responses in Rhesus Macaques

Journal of Biomedicine and Biotechnology ◽

10.1155/2010/860160 ◽

2010 ◽

Vol 2010 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Hong Qin ◽

Pramod N. Nehete ◽

Hong He ◽

Bharti Nehete ◽

Stephanie Buchl ◽

...

Keyword(s):

T Cell ◽

Dna Vaccine ◽

Rhesus Macaques ◽

Hiv Vaccine ◽

T Cell Immunity ◽

Long Term Memory ◽

Cell Immunity ◽

Gp120 Protein ◽

One Year

HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed. A prime-boost strategy using a novel HIV glycoprotein 120 DNA vaccine was employed to immunize rhesus macaques. The DNA vaccine encoded a chimeric gp120 protein in fusion with monocyte chemoattractant protein-3, which was hypothesized to improve the ability of antigen-presenting cells to capture viral antigen through chemokine receptor-mediated endocytosis. DNA vaccination induced virus-reactive T cells in peripheral blood, detectable by T cell proliferation, INFγELISPOT and sustained IL-6 production, without humoral responses. With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted. Surprisingly, long-term and peptide-specific mucosal memory T-cell immunity was detected in both vaccinated macaques after one year. Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

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Declining Levels of Neutralizing Antibodies Against SARS-CoV-2 in Convalescent COVID-19 Patients One Year Post Symptom Onset

Frontiers in Immunology ◽

10.3389/fimmu.2021.708523 ◽

2021 ◽

Vol 12 ◽

Author(s):

Tiandan Xiang ◽

Boyun Liang ◽

Yaohui Fang ◽

Sihong Lu ◽

Sumeng Li ◽

...

Keyword(s):

Symptom Onset ◽

Neutralizing Antibodies ◽

Natural Infection ◽

Protein S ◽

Igg Antibodies ◽

Neutralizing Activity ◽

Specific Igg ◽

One Year ◽

Kinetics Of

Major advances have been made in understanding the dynamics of humoral immunity briefly after the acute coronavirus disease 2019 (COVID-19). However, knowledge concerning long-term kinetics of antibody responses in convalescent patients is limited. During a one-year period post symptom onset, we longitudinally collected 162 samples from 76 patients and quantified IgM and IgG antibodies recognizing the nucleocapsid (N) protein or the receptor binding domain (RBD) of the spike protein (S). After one year, approximately 90% of recovered patients still had detectable SARS-CoV-2-specific IgG antibodies recognizing N and RBD-S. Intriguingly, neutralizing activity was only detectable in ~43% of patients. When neutralization tests against the E484K-mutated variant of concern (VOC) B.1.351 (initially identified in South Africa) were performed among patients who neutralize the original virus, the capacity to neutralize was even further diminished to 22.6% of donors. Despite declining N- and S-specific IgG titers, a considerable fraction of recovered patients had detectable neutralizing activity one year after infection. However, neutralizing capacities, in particular against an E484K-mutated VOC were only detectable in a minority of patients one year after symptomatic COVID-19. Our findings shed light on the kinetics of long-term immune responses after natural SARS-CoV-2 infection and argue for vaccinations of individuals who experienced a natural infection to protect against emerging VOC.

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Alternative Reproductive Tactics and Reproductive Success in Male Rhesus Macaques

Behaviour ◽

10.1163/156853994x00604 ◽

1994 ◽

Vol 129 (3-4) ◽

pp. 177-201 ◽

Cited By ~ 88

Author(s):

Peter Nurnberg ◽

John D. Berard ◽

Jorg T. Epplen ◽

Jorg Schmidtke

Keyword(s):

Reproductive Success ◽

Rhesus Macaques ◽

Alternative Reproductive Tactics ◽

Alternative Tactics ◽

Reproductive Tactics ◽

High Ranking ◽

One Year ◽

Reproductive Tactic ◽

Male Rhesus

AbstractMale rhesus macaques on Cayo Santiago use rank-dependent alternative reproductive tactics. High-ranking males can form long-term consorts and guard female mates while low-ranking males frequently resort to quick copulations under the cover of vegetation. No single reproductive tactic provided the Group S males with a definitive reproductive advantage during the one-year study. Males using the long-term tactic and the quick, stealth tactic sired five offspring each, but fewer males used the long-term consort tactic. Males using the long-term reproductive tactic have significantly greater mating success than males using the quick, sneaky tactic, and may have greater reproductive success. The highest-ranking males who form long-term consorts had the greatest degree of reproductive success. This indicates that for the highest-ranking males, forming long-term consorts is the most effective reproductive tactic. The effectiveness of alternative tactics for high-ranking males (i.e. consort disruption and possessive following) was equivocal. Consort disruption had no immediate effect on reproductive success. Possessive following may have resulted in the siring of two offspring by the alpha male, but was ineffective in other cases, where the females were inseminated by subordinate males. The effectiveness of the quick, furtive tactic was demonstrated by the siring of 45% of the infants by males who used this tactic.

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Engraftment of Insulin-Producing Cells from Porcine Islets in Non-Immune-Suppressed Rats or Nonhuman Primates Transplanted Previously with Embryonic Pig Pancreas

Journal of Transplantation ◽

10.1155/2011/261352 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Marc R. Hammerman

Keyword(s):

Immune Suppression ◽

Nonhuman Primates ◽

Rhesus Macaques ◽

Diabetic Rats ◽

Immunosuppressive Drug ◽

Cell Component ◽

Porcine Islets ◽

Insulin Producing Cells ◽

Transplantation Therapy

Transplantation therapy for diabetes is limited by unavailability of donor organs and outcomes complicated by immunosuppressive drug toxicity. Xenotransplantation is a strategy to overcome supply problems. Implantation of tissue obtained early during embryogenesis is a way to reduce transplant immunogenicity. Insulin-producing cells originating from embryonic pig pancreas obtained very early following pancreatic primordium formation (embryonic day 28 (E28)) engraft long-term in non-immune, suppressed diabetic rats or rhesus macaques. Morphologically, similar cells originating from adult porcine islets of Langerhans (islets) engraft in non-immune-suppressed rats or rhesus macaques previously transplanted with E28 pig pancreatic primordia. Our data are consistent with induction of tolerance to an endocrine cell component of porcine islets induced by previous transplantation of embryonic pig pancreas, a novel finding we designate organogenetic tolerance. The potential exists for its use to enable the use of pigs as islet cell donors for humans with no immune suppression requirement.

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Effects of Environmental Factors and Cultural Practices on Bull's Eye Rot of Pear

Plant Disease ◽

10.1094/pdis-92-3-0421 ◽

2008 ◽

Vol 92 (3) ◽

pp. 421-424 ◽

Cited By ~ 13

Author(s):

Jose L. Henriquez ◽

David Sugar ◽

Robert A. Spotts

Keyword(s):

Environmental Factors ◽

Cultural Practices ◽

Natural Infection ◽

Effect Of Temperature ◽

Growing Seasons ◽

Long Term Storage ◽

One Year ◽

Bull's Eye ◽

Term Storage

Bull's eye rot of pome fruits caused by Neofabraea spp. is characterized by infection occurring in the orchard throughout the growing season whereas rot lesions develop during long-term storage after harvest. Bull's eye rot was observed on pear fruit exposed to natural infection for any of six to nine sequential 1-to-2-week exposure periods during two growing seasons. Highest infection levels were associated with exposure closest to harvest. Over-tree irrigation and late harvest resulted in higher bull's eye rot incidence than under-tree irrigation and early or mid-season harvest. Fruit were inoculated prior to harvest with Neofabraea perennans to determine the effect of environmental factors on the development of bull's eye rot. The effect of temperature was inconsistent; disease was greatest at 10°C in one year of study but greatest at 30°C in the second year. Bull's eye rot developed independently of wetness durations longer than 0.5 h.

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Long-Term Programming of Antigen-Specific Immunity from Gene Expression Signatures in the PBMC of Rhesus Macaques Immunized with an SIV DNA Vaccine

PLoS ONE ◽

10.1371/journal.pone.0019681 ◽

2011 ◽

Vol 6 (6) ◽

pp. e19681 ◽

Cited By ~ 21

Author(s):

Sarah E. Belisle ◽

Jiangmei Yin ◽

Devon J. Shedlock ◽

Anlan Dai ◽

Jian Yan ◽

...

Keyword(s):

Gene Expression ◽

Dna Vaccine ◽

Rhesus Macaques ◽

Specific Immunity ◽

Gene Expression Signatures

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Long-Term Humoral Immune Response against SARS-CoV-2 after Natural Infection and Subsequent Vaccination According to WHO International Binding Antibody Units (BAU/mL)

Viruses ◽

10.3390/v13122336 ◽

2021 ◽

Vol 13 (12) ◽

pp. 2336

Author(s):

Natalia Ruetalo ◽

Bertram Flehmig ◽

Michael Schindler ◽

Lutz Pridzun ◽

Angelika Haage ◽

...

Keyword(s):

Natural Infection ◽

Serum Samples ◽

N Protein ◽

Humoral Immune ◽

Reference Preparation ◽

Binding Antibody ◽

One Year ◽

Definition Of ◽

The Individual

The new WHO reference standard allows for the definition of serum antibodies against various SARS-CoV-2 antigens in terms of binding antibody units (BAU/mL) and thus to compare the results of different ELISA systems. In this study, the concentration of antibodies (ABs) against both the S- and the N-protein of SARS-CoV-2 as well as serum neutralization activity were evaluated in three patients after a mild course of COVID-19. Serum samples were collected frequently during a period of over one year. Furthermore, in two individuals, the effects of an additional vaccination with a mRNA vaccine containing the S1-RBD sequence on these antibodies were examined. After natural infection, the antibodies (IgA, IgG) against the S1-protein remained elevated above the established cut-off to positivity (S-IgA 60 BAU/mL and S-IgG 50 BAU/mL, respectively) for over a year in all patients, while this was not the case for ABs against the N-protein (cut-off N-IgG 40 BAU/mL, N-IgA 256 BAU/mL). Sera from all patients retained the ability to neutralize SARS-CoV-2 for more than a year. Vaccination resulted in a rapid boost of antibodies to S1-protein but, as expected, not to the N-protein. Most likely, the wide use of the WHO reference preparation will be very useful in determining the individual immune status of patients after an infection with SARS-CoV-2 or after vaccination.

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Clinical course impacts early kinetics and long-term magnitude and amplitude of SARS-CoV-2 neutralizing antibodies beyond one year after infection

10.1101/2021.08.12.21261921 ◽

2021 ◽

Author(s):

Edwards Pradenas ◽

Benjamin Trinité ◽

Víctor Urrea ◽

Silvia Marfil ◽

Ferran Tarrés-Freixas ◽

...

Keyword(s):

B Cells ◽

Neutralizing Antibodies ◽

Primary Infection ◽

Natural Infection ◽

Optimal Strategies ◽

Longitudinal Models ◽

Neutralizing Activity ◽

Cross Neutralization ◽

One Year

Background: Understanding the determinants of long-term immune responses to SARS-CoV-2 and the concurrent impact of vaccination and emerging variants of concern will guide optimal strategies to achieve global protection against the COVID-19 pandemic. Methods: A prospective cohort of 332 COVID-19 patients was followed beyond one year. Plasma neutralizing activity was evaluated using HIV-based reporter pseudoviruses expressing different SARS-CoV-2 spikes and was longitudinally analyzed using mixed-effects models. Findings: Long-term neutralizing activity was stable beyond one year after infection in mild/asymptomatic and hospitalized participants. However, longitudinal models suggest that hospitalized individuals generate both short- and long-lived memory B cells, while outpatient responses were dominated by long-lived B cells. In both groups, vaccination boosted responses to natural infection, although viral variants, mainly B.1.351, reduced the efficacy of neutralization. Importantly, despite showing higher neutralization titers, hospitalized patients showed lower cross-neutralization of B.1.351 variant compared to outpatients. Multivariate analysis identified severity of primary infection as the factor that independently determines both the magnitude and the inferior cross-neutralization activity of long-term neutralizing responses. Conclusions: Neutralizing response induced by SARS-CoV-2 is heterogeneous in magnitude but stable beyond one year after infection. Vaccination boosts these long-lasting natural neutralizing responses, counteracting the significant resistance to neutralization of new viral variants. Severity of primary infection determines higher magnitude but poorer quality of long-term neutralizing responses.

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Induction of Plasmodium falciparum Transmission-Blocking Antibodies in Nonhuman Primates by a Combination of DNA and Protein Immunizations

Infection and Immunity ◽

10.1128/iai.72.1.253-259.2004 ◽

2004 ◽

Vol 72 (1) ◽

pp. 253-259 ◽

Cited By ~ 43

Author(s):

Cevayir Coban ◽

Mario T. Philipp ◽

Jeanette E. Purcell ◽

David B. Keister ◽

Mobolaji Okulate ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Antibody Response ◽

Dna Vaccine ◽

Nonhuman Primates ◽

Rhesus Macaques ◽

Surface Protein ◽

Mosquito Vector ◽

Transmission Blocking ◽

Membrane Feeding ◽

Antibody Titers

ABSTRACT Malaria transmission-blocking vaccination can effectively reduce and/or eliminate transmission of parasites from the human host to the mosquito vector. The immunity achieved by inducing an antibody response to surface antigens of male and female gametes and parasite stages in the mosquito. Our laboratory has developed DNA vaccine constructs, based on Pfs25 (a Plasmodium falciparum surface protein of 25 kDa), that induce a transmission-blocking immune response in mice (C. A. Lobo, R. Dhar, and N. Kumar, Infect. Immun. 67:1688-1693, 1999). To evaluate the safety, immunogenicity, and efficacy of the Pfs25 DNA vaccine in nonhuman primates, we immunized rhesus macaques (Macaca mulatta) with a DNA vaccine plasmid encoding Pfs25 or a Pfg27-Pfs25 hybrid or with the plasmid (empty plasmid) alone. Immunization with four doses of these DNA vaccine constructs elicited antibody titers that were high but nonetheless unable to reduce the parasite's infectivity in membrane feeding assays. Further boosting of the antibody response with recombinant Pfs25 formulated in Montanide ISA-720 increased antibody titers (30-fold) and significantly blocked transmission of P. falciparum gametocytes to Anopheles mosquitoes (∼90% reduction in oocyst numbers in the midgut). Our data show that a DNA prime-protein boost regimen holds promise for achieving transmission-blocking immunity in areas where malaria is endemic and could be effective in eradicating malaria in isolated areas where the level of malaria endemicity is low.

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Design and immunogenicity of a Pan-SARS-CoV-2 synthetic DNA vaccine

10.1101/2021.05.11.443592 ◽

2021 ◽

Author(s):

Charles C Reed ◽

Katherine Schultheis ◽

Viviane M Andrade ◽

Richa Kalia ◽

Jared Tur ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Dna Vaccine ◽

Murine Model ◽

Neutralizing Antibodies ◽

First Generation ◽

Synthetic Dna ◽

Cell Responses ◽

Escape Mutants ◽

Humoral Responses

First generation COVID-19 vaccines matched to the original Wuhan-Hu-1 (WT) strain are showing reduced efficacy against emerging SARS-CoV-2 variants of concern (VOC). In response, next generation vaccines either matched to a single variant or designed to provide broader coverage across the VOC group are being developed. The latter pan-SARS-CoV-2 approach may offer substantial advantages in terms of cross-strain protection, immune coverage, reduced susceptibility to escape mutants, and non-restricted geographical use. Here we have employed our SynCon® design technology to construct a DNA vaccine expressing a pan-Spike immunogen (INO-4802) to induce broad immunity across SARS-CoV-2 variants. Compared to WT and VOC-matched vaccines which showed limited cross-neutralizing activity, INO-4802 induced potent neutralizing antibodies and T cell responses against WT as well as B.1.1.7, P.1, and B.1.351 VOCs in a murine model. In addition, a hamster vaccination model showed enhanced humoral responses against VOCs in a heterologous pWT prime/INO-4802 boost setting. These results demonstrate the potential of the pan-SARS-CoV-2 vaccine, INO-4802 to induce cross-reactive immune responses against emerging VOCs as either a standalone vaccine, or as a potential boost for individuals previously immunized with WT-matched vaccines.

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