Introduction
Vaccines are biological products that elicit a protective immune response. The details of the manufacturing processes are varied depending on the particular characteristics of the vaccine.
There are classically, three basic types of vaccines against viral and bacterial pathogens (For mRNA-, DNA- and vector-vaccines see Chapters 7, 8, 9):
Live-attenuated.
Killed (non-live).
Subunit.
“Classical” Vaccine Production
The basic classical process includes 5 phases: expression, harvest, inactivation, purification, formulation.
The expression systems for viral and bacterial vaccines are distinct. Bacterial expression is performed in fermenters. Viral vaccines are produced in animal cell culture or embryonated chicken eggs.
Processes for whole viral or bacterial vaccines often involve only limited processing after expression.
Subunit vaccines routinely require the most purification to separate the product from other contaminants.
Challenges
Challenges for bacterial vaccines include testing to ensure the safety and efficacy of the product.
Inactivation procedures need to be carefully controlled.
Live attenuated vaccines need to be tested to ensure the vaccine strains are still safe and effective.
Viral vaccines require testing to ensure foreign infectious agents are not introduced during processing.
Both cultured cells and egg present risks for infection.
Live viral vaccines and gene vectors need to be carefully engineered and tested to minimize safety concerns.
Highly variable vaccine targets such as influenza need to be re-adapted to current circulating strains.
Correction to: Animal Cell Expression Systems
