Clinical Trial Phase I trials are the first stage of human testing, usually involving a small number of healthy volunteers or target participants. The primary goal is to evaluate preliminary safety, tolerability and immunogenicity.

Clinical Trial Phase II trials involve a larger group of participants to further assess safety and immunogenicity. These studies may also explore dosage, vaccination schedule and target population, providing key data for Phase III trial design.

Clinical Trial Phase III trials are large-scale studies designed to confirm safety, immunogenicity and protective efficacy in the intended population. The results provide critical evidence to support regulatory review and potential product approval.

Regulatory Review / Registration is the final stage of vaccine development, during which regulatory authorities assess the complete clinical, nonclinical and CMC data package to confirm whether the product meets required standards for safety, efficacy and quality, supporting product registration and marketing authorization.