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1.
Vaccine ; 40(21): 2960-2969, 2022 05 09.
Article in English | MEDLINE | ID: covidwho-1773836

ABSTRACT

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 T cells and 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.


Subject(s)
COVID-19 , Vaccines, DNA , Viral Vaccines , Animals , Antibody Formation , COVID-19/prevention & control , COVID-19 Vaccines , Humans , Macaca mulatta , Mice , Mice, Inbred BALB C , SARS-CoV-2 , Vaccination
2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-321794

ABSTRACT

The coronavirus family member, SARS-CoV-2 has been identified as the causal agent for the outbreak of viral pneumonia disease, COVID-19 which first emerged in mid-December 2019 in the city of Wuhan in central China. As of February 25, 2020 there are 80,994 people infected and 2,760 deaths, and documented human-to-human transmission across multiple continents. At this time, no vaccine is available to control further dissemination of the disease. We have previously developed a synthetic DNA vaccine targeting the MERS coronavirus Spike (S) protein that was deployed in response to the MERS outbreak in South Korea. This vaccine induced potent antibody and CTL responses, and provided protection in a NHP challenge model. In the clinic, the vaccine generated humoral immunity including neutralizing antibody responses, as well as T cell immunity. Here we build on this prior work and report on the rapid development of a synthetic DNA-based vaccine targeting the major surface antigen Spike protein of SARS-CoV-2. The engineered construct, INO-4800 induced robust expression of the Spike protein in vitro, and generated antibody and T cell responses following a single immunization in mice and guinea pigs. This preliminary dataset identifies INO-4800 as a potential COVID-19 vaccine candidate, supporting further study for mobilization against this emerging disease threat.

3.
Cell Rep ; 38(5): 110318, 2022 02 01.
Article in English | MEDLINE | ID: covidwho-1654152

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines may target epitopes that reduce durability or increase the potential for escape from vaccine-induced immunity. Using synthetic vaccinology, we have developed rationally immune-focused SARS-CoV-2 Spike-based vaccines. Glycans can be employed to alter antibody responses to infection and vaccines. Utilizing computational modeling and in vitro screening, we have incorporated glycans into the receptor-binding domain (RBD) and assessed antigenic profiles. We demonstrate that glycan-coated RBD immunogens elicit stronger neutralizing antibodies and have engineered seven multivalent configurations. Advanced DNA delivery of engineered nanoparticle vaccines rapidly elicits potent neutralizing antibodies in guinea pigs, hamsters, and multiple mouse models, including human ACE2 and human antibody repertoire transgenics. RBD nanoparticles induce high levels of cross-neutralizing antibodies against variants of concern with durable titers beyond 6 months. Single, low-dose immunization protects against a lethal SARS-CoV-2 challenge. Single-dose coronavirus vaccines via DNA-launched nanoparticles provide a platform for rapid clinical translation of potent and durable coronavirus vaccines.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Nanoparticles/administration & dosage , SARS-CoV-2/immunology , Animals , Antibodies, Neutralizing/immunology , Binding Sites , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/genetics , Cricetinae , Epitopes , Guinea Pigs , Immunogenicity, Vaccine , Mice , Nanoparticles/chemistry , Nucleic Acid-Based Vaccines/administration & dosage , Nucleic Acid-Based Vaccines/chemistry , Nucleic Acid-Based Vaccines/genetics , Nucleic Acid-Based Vaccines/immunology , Polysaccharides/chemistry , Polysaccharides/genetics , Polysaccharides/immunology , SARS-CoV-2/chemistry , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccine Potency
4.
NPJ Vaccines ; 6(1): 121, 2021 Oct 14.
Article in English | MEDLINE | ID: covidwho-1469970

ABSTRACT

Global surveillance has identified emerging SARS-CoV-2 variants of concern (VOC) associated with broadened host specificity, pathogenicity, and immune evasion to vaccine-induced immunity. Here we compared humoral and cellular responses against SARS-CoV-2 VOC in subjects immunized with the DNA vaccine, INO-4800. INO-4800 vaccination induced neutralizing antibodies against all variants tested, with reduced levels detected against B.1.351. IFNγ T cell responses were fully maintained against all variants tested.

5.
Cell Rep Med ; 2(10): 100420, 2021 10 19.
Article in English | MEDLINE | ID: covidwho-1450242

ABSTRACT

Coronavirus disease 2019 (COVID-19), caused by the SARS-CoV-2 virus, has had a dramatic global impact on public health and social and economic infrastructures. Here, we assess the immunogenicity and anamnestic protective efficacy in rhesus macaques of an intradermal (i.d.)-delivered SARS-CoV-2 spike DNA vaccine, INO-4800, currently being evaluated in clinical trials. Vaccination with INO-4800 induced T cell responses and induced spike antigen and RBD binding antibodies with ADCP and ADCD activity. Sera from the animals neutralized both the D614 and G614 SARS-CoV-2 pseudotype viruses. Several months after vaccination, animals were challenged with SARS-CoV-2 resulting in rapid recall of anti-SARS-CoV-2 spike protein T cell and neutralizing antibody responses. These responses were associated with lower viral loads in the lung. These studies support the immune impact of INO-4800 for inducing both humoral and cellular arms of the adaptive immune system, which are likely important for providing durable protection against COVID-19 disease.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Lung/virology , T-Lymphocytes/immunology , Animals , Antibodies, Neutralizing/blood , COVID-19 Vaccines/therapeutic use , Female , Injections, Intradermal , Macaca mulatta , Male , SARS-CoV-2/immunology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/administration & dosage , Vaccines, DNA/therapeutic use , Viral Load
6.
Vaccine ; 39(34): 4885-4894, 2021 08 09.
Article in English | MEDLINE | ID: covidwho-1284599

ABSTRACT

Safe and effective vaccines will provide essential medical countermeasures to tackle the COVID-19 pandemic. Here, we assessed the safety, immunogenicity and efficacy of the intradermal delivery of INO-4800, a synthetic DNA vaccine candidate encoding the SARS-CoV-2 spike protein in the rhesus macaque model. Single and 2 dose vaccination regimens were evaluated. Vaccination induced both binding and neutralizing antibodies, along with IFN-γ-producing T cells against SARS-CoV-2. Upon administration of a high viral dose (5 × 106 pfu) via the intranasal and intratracheal routes we observed significantly reduced virus load in the lung and throat, in the vaccinated animals compared to controls. 2 doses of INO-4800 was associated with more robust vaccine-induced immune responses and improved viral protection. Importantly, histopathological examination of lung tissue provided no indication of vaccine-enhanced disease following SARS-CoV-2 challenge in INO-4800 immunized animals. This vaccine candidate is currently under clinical evaluation as a 2 dose regimen.


Subject(s)
COVID-19 , Vaccines, DNA , Viral Vaccines , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19 Vaccines , Humans , Macaca mulatta , Pandemics , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
7.
JCI Insight ; 6(10)2021 05 24.
Article in English | MEDLINE | ID: covidwho-1197299

ABSTRACT

Emerging coronaviruses from zoonotic reservoirs, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been associated with human-to-human transmission and significant morbidity and mortality. Here, we study both intradermal and intramuscular 2-dose delivery regimens of an advanced synthetic DNA vaccine candidate encoding a full-length MERS-CoV spike (S) protein, which induced potent binding and neutralizing antibodies as well as cellular immune responses in rhesus macaques. In a MERS-CoV challenge, all immunized rhesus macaques exhibited reduced clinical symptoms, lowered viral lung load, and decreased severity of pathological signs of disease compared with controls. Intradermal vaccination was dose sparing and more effective in this model at protecting animals from disease. The data support the further study of this vaccine for preventing MERS-CoV infection and transmission, including investigation of such vaccines and simplified delivery routes against emerging coronaviruses.


Subject(s)
Coronavirus Infections/veterinary , Macaca mulatta/immunology , Middle East Respiratory Syndrome Coronavirus/immunology , Vaccines, DNA/therapeutic use , Viral Vaccines/therapeutic use , Animals , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Immunogenicity, Vaccine , Injections, Intradermal , Middle East Respiratory Syndrome Coronavirus/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Vaccines, DNA/administration & dosage , Vaccines, DNA/genetics , Viral Vaccines/administration & dosage , Viral Vaccines/genetics
8.
EClinicalMedicine ; 31: 100689, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-987565

ABSTRACT

BACKGROUND: A vaccine against SARS-CoV-2 is of high urgency. Here the safety and immunogenicity induced by a DNA vaccine (INO-4800) targeting the full length spike antigen of SARS-CoV-2 are described. METHODS: INO-4800 was evaluated in two groups of 20 participants, receiving either 1.0 mg or 2.0 mg of vaccine intradermally followed by CELLECTRA® EP at 0 and 4 weeks. Thirty-nine subjects completed both doses; one subject in the 2.0 mg group discontinued trial participation prior to receiving the second dose. ClinicalTrials.gov identifier: NCT04336410. FINDINGS: The median age was 34.5, 55% (22/40) were men and 82.5% (33/40) white. Through week 8, only 6 related Grade 1 adverse events in 5 subjects were observed. None of these increased in frequency with the second administration. No serious adverse events were reported. All 38 subjects evaluable for immunogenicity had cellular and/or humoral immune responses following the second dose of INO-4800. By week 6, 95% (36/38) of the participants seroconverted based on their responses by generating binding (ELISA) and/or neutralizing antibodies (PRNT IC50), with responder geometric mean binding antibody titers of 655.5 [95% CI (255.6, 1681.0)] and 994.2 [95% CI (395.3, 2500.3)] in the 1.0 mg and 2.0 mg groups, respectively. For neutralizing antibody, 78% (14/18) and 84% (16/19) generated a response with corresponding geometric mean titers of 102.3 [95% CI (37.4, 280.3)] and 63.5 [95% CI (39.6, 101.8)], in the respective groups. By week 8, 74% (14/19) and 100% (19/19) of subjects generated T cell responses by IFN-É£ ELISpot assay with the median SFU per 106 PBMC of 46 [95% CI (21.1, 142.2)] and 71 [95% CI (32.2, 194.4)] in the 1.0 mg and 2.0 mg groups, respectively. Flow cytometry demonstrated a T cell response, dominated by CD8+ T cells co-producing IFN-É£ and TNF-α, without increase in IL-4. INTERPRETATION: INO-4800 demonstrated excellent safety and tolerability and was immunogenic in 100% (38/38) of the vaccinated subjects by eliciting either or both humoral or cellular immune responses. FUNDING: Coalition for Epidemic Preparedness Innovations (CEPI).

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