Vecantoxatag

Phase I Main objective: To evaluate the safety and tolerability of a single intramuscular injection of different doses of GR2001 injection in healthy Chinese adult subjects. Secondary objectives: (1) To evaluate the pharmacokinetic characteristics of a single intramuscular injection of different doses of GR2001 injection in healthy Chinese adult subjects; (2) To evaluate the pharmacodynamic characteristics of a single intramuscular injection of different doses of GR2001 injection in healthy Chinese adult subjects; (3) To evaluate the immunogenicity characteristics of a single intramuscular injection of different doses of GR2001 injection in healthy Chinese adult subjects. Phase II Main objective: To compare the pharmacodynamic characteristics of intramuscular injection of different doses of GR2001 injection combined with adsorbed tetanus vaccine and tetanus human immunoglobulin combined with adsorbed tetanus vaccine in Chinese adult subjects. Secondary objectives: (1) To compare the safety of intramuscular injection of different doses of GR2001 injection combined with adsorbed tetanus vaccine and tetanus human immunoglobulin combined with adsorbed tetanus vaccine in Chinese adult subjects; (2) To compare the pharmacodynamic characteristics of intramuscular injection of different doses of GR2001 injection combined with adsorbed tetanus vaccine and placebo combined with adsorbed tetanus vaccine in Chinese adult subjects; (3) To compare the pharmacokinetic characteristics of intramuscular injection of different doses of GR2001 injection combined with adsorbed tetanus vaccine in Chinese adult subjects; (4) To compare the immunogenicity characteristics of intramuscular injection of different doses of GR2001 injection combined with adsorbed tetanus vaccine in Chinese adult subjects.