Immunogenicity and safety of SpikoGen®, an adjuvanted recombinant SARS‐CoV‐2 spike protein vaccine as a homologous and heterologous booster vaccination: A randomized placebo‐controlled trial. Issue 3 (13th July 2022)

• Record Type: Journal Article
• Authors: Tabarsi, Payam; Anjidani, Nassim; Shahpari, Ramin; Roshanzamir, Khashayar; Fallah, Newsha; Andre, Greiciely; Petrovsky, Nikolai; Barati, Saghar
• Is Part Of: Immunology. Volume 167:Issue 3(2022)
• Page Start: 340
• Page End: 353
• Publication Date: 2022-07-13
• Subjects: booster -- COVID‐19 -- cross‐neutralization -- SARS‐CoV‐2 -- SpikoGen; Immunology -- Periodicals
• DOI: 10.1111/imm.13540
• Languages: English
• ISSNs: 0019-2805

Abstract

Abstract: SpikoGen® is a subunit recombinant spike protein vaccine combined with Advax‐CpG55.2™ adjuvant. This COVID‐19 vaccine was shown to be safe, immunogenic and efficacious in previous clinical trials. This study aimed to assess the safety and immunogenicity of SpikoGen® vaccine as a homologous and heterologous booster vaccination. This double‐blind and randomized placebo‐controlled (5:1) trial was performed on 300 already vaccinated participants. SpikoGen® or saline placebo was administered as a booster dose to participants who had received a full two‐dose COVID‐19 vaccination course. Immunogenicity assessments were done 14 days after the booster dose with the primary immunogenicity outcome seroconversion rate of neutralizing antibodies. Safety outcomes included the incidence of solicited adverse events up to 7 days after the booster dose. SpikoGen® vaccine induced a robust humoral response both as a homologous and heterologous booster, when compared to the placebo. At Day 14, seroconversion of neutralizing antibodies was 76% (95% confidence interval [CI]: 69%–82%) in the SpikoGen® group versus 3% (95% CI: 0%–13%) in the placebo group. The most common local and systemic reported adverse events were injection site pain and fatigue. No serious adverse events were reported. The SpikoGen®‐booster induced cross‐neutralization of other SARS‐CoV‐2 variants. Irrespective of the primary vaccine course received, SpikoGen® vaccine showed promising effects as both a homologous and heterologous booster dose. This vaccine also had a good safety profile with no vaccine‐associated serious adverse events. On the basis of these results, SpikoGen® vaccine has been approved as a booster dose. Abstract : Shown are geometric mean concentration (GMC) in the per‐protocol set for sVNTw responses (panel a), S1w IgG responses (panel b) and RBDw IgG responses (panel c) at Days 0 and 14 (14 days after the booster dose). Antibody values below the LLOQ were replaced by 0.5 × LLOQ. The 95% CI was calculated based on the t‐distribution of the log‐transformed values for GMC and GM levels, then back‐transformed to the original scale for presentation. CI, confidence interval; RBDw, receptor‐binding domain (W subscript refers to the Wuhan‐Hu‐1 strain); S1w, S1w part of the spike protein (W subscript refers to the Wuhan‐Hu‐1 strain); sVNTw, surrogate virus‐neutralizing test (W subscript refers to the Wuhan‐Hu‐1 strain).