Gritstone COVID-19 Vaccine Clinical Trial
This is a multicenter, US-only, phase 1, open-label, dose and age escalation, parallel design (heterologous and homologous prime-boost) study to examine safety, tolerability, and immunogenicity of investigational Chimpanzee Adenovirus serotype 68 (ChAd) and self-amplifying mRNA (SAM) vectors expressing either Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike alone, or spike plus additional SARS-CoV-2 T cell epitopes (TCE) in healthy adult subjects. Stage 1 will compare ChAd and SAM vaccines encoding only the spike protein in a 2-group dose escalation trial in subjects 18-60 years old, and a 3-group dose escalation trial in subjects over 60 years old, focusing on heterologous ChAd prime/SAM boost and homologous SAM prime/SAM boost regimens including sentinels, and staggered enrollment for dose and age escalations. Stage 2 will compare optimal doses of ChAd and SAM vaccines (determined in Stage 1) encoding both spike and TCE, in subjects 18 years and older enrolled into up to 6 groups simultaneously to receive homologous SAM prime/SAM boost, homologous ChAd prime/ChAd boost and heterologous ChAd prime/SAM boost combinations. Up to 70 (Stage 1) and up to 70 (Stage 2) males and non-pregnant females >/= 18 years of age who are in good health, do not have high risks for SARS-CoV-2 infection or for severe Coronavirus Disease 2019 (COVID-19) disease progression, and meet all eligibility criteria will be enrolled. Subjects will be enrolled at one of at least 3 distinct US-based Infectious Diseases Clinical Research Consortium (IDCRC) sites into different groups based on their age (18-60 and >60 years old). The primary objective of this study is to assess the safety and tolerability of different doses of ChAd-S (or ChAd-S-TCE) and SAM-S (or SAM-S-TCE) when administered as prime and/or boost in healthy adult subjects including older adult subjects.