Vaccine design and development involves creating safe, effective vaccines through understanding pathogens, identifying antigens, and using various vaccine platforms (e.g., mRNA, viral vectors, subunit vaccines). It includes preclinical research, clinical trials (Phases 1-3), regulatory approval, and mass production. Innovations like reverse vaccinology and mRNA technology enable rapid responses to emerging threats, as seen during COVID-19. Ongoing surveillance ensures vaccine safety. Collaborative efforts, such as the World Vaccines R&D Conference, drive progress in this field.