SARS-CoV-2 DNA Vaccine INO-4800 Induces Durable Immune Responses Capable of Being Boosted in a Phase 1 Open-Label Trial. (25th January 2022)

• Record Type: Journal Article
• Authors: Kraynyak, Kimberly A; Blackwood, Elliott; Agnes, Joseph; Tebas, Pablo; Giffear, Mary; Amante, Dinah; Reuschel, Emma L; Purwar, Mansi; Christensen-Quick, Aaron; Liu, Neiman; Andrade, Viviane M; Diehl, Malissa C; Wani, Snehal; Lupicka, Martyna; Sylvester, Albert; Morrow, Matthew P; Pezzoli, Patrick; McMullan, Trevor; Kulkarni, Abhijeet J; Zaidi, Faraz I; Frase, Drew; Liaw, Kevin; Smith, Trevor R F; Ramos, Stephanie J; Ervin, John; Adams, Mark; Lee, Jessica; Dallas, Michael; Shah Brown, Ami; Shea, Jacqueline E; Kim, J Joseph; Weiner, David B; Broderick, Kate E; Humeau, Laurent M; Boyer, Jean D; Mammen, Mammen P;
• Is Part Of: Journal of infectious diseases. Volume 225:Number 11(2022)
• Page Start: 1923
• Page End: 1932
• Publication Date: 2022-01-25
• Subjects: SARS-CoV-2 -- clinical trial -- DNA vaccine -- INO-4800 -- COVID-19 -- safety -- immunogenicity -- booster; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiac016
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Additional severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines that are safe and effective as primary vaccines and boosters remain urgently needed to combat the coronavirus disease 2019 (COVID-19) pandemic. We describe safety and durability of immune responses following 2 primary doses and a homologous booster dose of an investigational DNA vaccine (INO-4800) targeting full-length spike antigen. Methods: Three dosage strengths of INO-4800 (0.5 mg, 1.0 mg, and 2.0 mg) were evaluated in 120 age-stratified healthy adults. Intradermal injection of INO-4800 followed by electroporation at 0 and 4 weeks preceded an optional booster 6–10.5 months after the second dose. Results: INO-4800 appeared well tolerated with no treatment-related serious adverse events. Most adverse events were mild and did not increase in frequency with age and subsequent dosing. A durable antibody response was observed 6 months following the second dose; a homologous booster dose significantly increased immune responses. Cytokine-producing T cells and activated CD8 + T cells with lytic potential were significantly increased in the 2.0-mg dose group. Conclusions: INO-4800 was well tolerated in a 2-dose primary series and homologous booster in all adults, including elderly participants. These results support further development of INO-4800 for use as primary vaccine and booster. Clinical Trials Registration: NCT04336410. Abstract : Two-milligram dose of INO-4800, DNA-based vaccine encoding SARS-CoV-2 spike protein, appears safe and well tolerated and elicits humoral and cell-mediated immunity persisting to 6 months after a second dose. A third dose 6–10.5 months later significantly boosts immune responses.