The first step in vaccine development is antigen discovery, a process that determines whether the vaccine can successfully stimulate a protective immune response. Pathogen-associated molecules can induce a specific immune response in the host, and the core goal of antigen discovery is to identify these molecules in order to prevent infection.

Antigen discovery typically begins with the screening of candidate antigens. High-throughput technologies (such as phage display technology or proteomics) are used to identify molecules that bind specifically to antibodies from the pathogen, which then helps to identify potential candidate antigens. These candidate antigens are further subjected to immunogenicity testing to assess whether they can trigger an immune response.

To ensure the safety and efficacy of the antigen in the vaccine, gene editing technologies may be employed to optimize the antigen and eliminate any potential adverse effects. After optimization, the antigen is produced in a stable expression system to provide materials for subsequent vaccine trials. Finally, the protective effect of the candidate vaccine is tested in animal models to identify the most promising antigens and to assess whether they can generate effective protective antibodies.