A vaccine is a biological preparation that stimulates the adaptive immune system to develop protective immunity against a specific pathogen or disease by introducing an antigen — such as an attenuated or inactivated virus, a recombinant protein, a viral vector, or a nucleic acid (e.g., mRNA or DNA) — that primes the immune system to recognize and respond to future exposures. Vaccines are classified into several categories, including live-attenuated, inactivated, subunit, viral vector-based, and mRNA vaccines, each with distinct manufacturing platforms, regulatory pathways, and storage requirements. Their GMP production demands specialized upstream cell culture or fermentation, downstream purification, formulation, fill and finish, and analytical characterization capabilities, all of which represent core service offerings of CDMOs in the vaccine manufacturing space.
