How vaccines are made

This British Society for Immunology animation follows a vaccine from the laboratory to the clinic. It explains the research, testing and manufacturing steps that every vaccine goes through, and what its ingredients are for.

What the video covers

• Laboratory research to design a vaccine
• Laboratory tests and clinical trials to show it is safe and effective
• The rigorous manufacturing process and quality checks
• The ingredients in a vaccine and why each one is there

The process

Vaccines are tested in stages. Phase 1 trials check safety in a small group. Phase 2 trials expand to hundreds of people to find the right dose. Phase 3 trials involve thousands or tens of thousands of people to confirm the vaccine works. Regulators then review the data before approval, and monitoring continues afterwards through reporting systems such as VAERS in the United States. Ingredients such as stabilizers, preservatives and adjuvants are used in tiny, well-studied amounts. Claims that they are "toxic" usually ignore the dose.

Related reading: Vaccine Ingredient Controversy, The Vaccine Adverse Event Reporting System (VAERS) and Thimerosal and Its Impact on Vaccine Usage.