Vaccine trial

[1] A vaccine candidate drug is first identified through preclinical evaluations that could involve high throughput screening and selecting the proper antigen to invoke an immune response.

[citation needed] Preclinical development stages are necessary to determine the immunogenicity potential and safety profile for a vaccine candidate.

[3] Scientific advances since the 1980s have helped to use transgenic animals as a part of vaccine preclinical protocol in hopes to more accurately determine drug reactions in humans.

Other drug trials focus on the pharmacodynamics and pharmacokinetics; however, in vaccine studies it is essential to understand toxic effects at all possible dosage levels and the interactions with the immune system.

Vaccine escalation studies aim to minimize chances of serious adverse effects (SAE) by slowly increasing the drug dosage or frequency.

[6] Phase II will consist of more healthy volunteers in the vaccine target population (~ hundreds of people) to determine reactions in a more diverse set of humans and test different schedules.

Harmful effects, such as increased risk of liver failure or heart attacks, discovered by Phase IV trials may result in a drug being no longer sold, or restricted to certain uses; examples include cerivastatin (brand names Baycol and Lipobay), troglitazone (Rezulin) and rofecoxib (Vioxx).