A Randomized, Observer-Blinded, Phase 1/2 Study With an Open-Label Group to Evaluate the Safety and Immunogenicity of SII Vaccine Constructs Based on SARS-CoV-2 Variants in Adults
This is a randomized, observer-blinded, Phase 1/2 study with an open-label group to evaluate the safety and immunogenicity of 3 novel SARS-CoV-2 variant vaccine constructs adjuvanted with Matrix-M1 adjuvant. Investigational products will include a monovalent SII SARS-CoV-2 B.1.351 (Beta) variant vaccine (SII B.1.351), a bivalent SII vaccine containing antigen for both the ancestral strain and B.1.351 (Beta) variant of SARS-CoV-2 (SII Bivalent), and a monovalent SII SARS-CoV-2 B.1.617.2 (Delta) variant vaccine (SII B.1.617.2).
B.1.351 SARS-CoV-2 Variant Exhibits Higher Virulence but Less Viral Shedding than That of the Ancestral Strain in Young Nonhuman Primates.
作者: Yu Bai ; Qian He ; Jinghuan Yang ; Shuaiyao Lu ; Qunying Mao ; Fan Gao ; Lianlian Bian ; Jialu Zhang ; Chaoqiang An ; Jianyang Liu ; Xing Wu ; Wenhai Yu ; Zhongfang Wang ; Xiaozhong Peng ; Junzhi Wang ; Zhenglun Liang ; Miao Xu
We investigated the distribution, virulence, and pathogenic characteristics of mutated SARS-CoV-2 to clarify the association between virulence and the viral spreading ability of current and future circulating strains. Chinese rhesus macaques were infected with ancestral SARS-CoV-2 strain GD108 and Beta variant B.1.351 (B.1.351) and assessed for clinical signs, viral distribution, pathological changes, and pulmonary inflammation. We found that GD108 replicated more efficiently in the upper respiratory tract, whereas B.1.351 replicated more efficiently in the lower respiratory tract and lung tissue, implying a reduced viral shedding and spreading ability of B.1.351 compared with that of GD108. Importantly, B.1.351 caused more severe lung injury and dramatically elevated the level of inflammatory cytokines compared with those observed after infection with GD108. Moreover, both B.1.351 and GD108 induced spike-specific T-cell responses at an early stage of infection, with higher levels of interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in the B.1.351 group and higher levels of interleukin 17 (IL-17) in the GD108 group, indicating a divergent pattern in the T-cell-mediated inflammatory "cytokine storm." This study provides a basis for exploring the pathogenesis of SARS-CoV-2 variants of concern (VOCs) and establishes an applicable animal model for evaluating the efficacy and safety of vaccines and drugs. IMPORTANCE One of the priorities of the current SARS-CoV-2 vaccine and drug research strategy is to determine the changes in transmission ability, virulence, and pathogenic characteristics of SARS-CoV-2 variants. In addition, nonhuman primates (NHPs) are suitable animal models for the study of the pathogenic characteristics of SARS-CoV-2 and could contribute to the understanding of pathogenicity and transmission mechanisms. As SARS-CoV-2 variants continually emerge and the viral biological characteristics change frequently, the establishment of NHP infection models for different VOCs is urgently needed. In the study, the virulence and tissue distribution of B.1.351 and GD108 were comprehensively studied in NHPs. We concluded that the B.1.351 strain was more virulent but exhibited less viral shedding than the latter. This study provides a basis for determining the pathogenic characteristics of SARS-CoV-2 and establishes an applicable animal model for evaluating the efficacy and safety of vaccines and drugs.
2022-03-31·Nature communications1区 · 综合性期刊
Protein-based SARS-CoV-2 spike vaccine booster increases cross-neutralization against SARS-CoV-2 variants of concern in non-human primates.
1区 · 综合性期刊
作者: Vincent Pavot ; Catherine Berry ; Michael Kishko ; Natalie G Anosova ; Dean Huang ; Tim Tibbitts ; Alice Raillard ; Sylviane Gautheron ; Cindy Gutzeit ; Marguerite Koutsoukos ; Roman M Chicz ; Valerie Lecouturier
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that partly evade neutralizing antibodies raises concerns of reduced vaccine effectiveness and increased infection. We previously demonstrated that the SARS-CoV-2 spike protein vaccine adjuvanted with AS03 (CoV2 preS dTM-AS03) elicits robust neutralizing antibody responses in naïve subjects. Here we show that, in macaques primed with mRNA or protein-based subunit vaccine candidates, one booster dose of CoV2 preS dTM-AS03 (monovalent D614 or B.1.351, or bivalent D614 + B.1.351 formulations), significantly boosts the pre-existing neutralizing antibodies against the parental strain from 177- to 370-fold. Importantly, the booster dose elicits high and persistent cross-neutralizing antibodies covering five former or current SARS-CoV-2 variants of concern (Alpha, Beta, Gamma, Delta and Omicron) and, unexpectedly, SARS-CoV-1. Interestingly, we show that the booster specifically increases the functional antibody responses as compared to the receptor binding domain (RBD)-specific responses. Our findings show that these vaccine candidates, when used as a booster, have the potential to offer cross-protection against a broad spectrum of variants. This has important implications for vaccine control of SARS-CoV-2 variants of concern and informs on the benefit of a booster with the vaccine candidates currently under evaluation in clinical trials.