When scientists produce a vaccine for a disease the vaccine is tested on live animals.

What is the next stage in testing the vaccine?

Tick (✔) one box.

The development of new drugs and vaccines follows a standard procedure. 1. **Preclinical testing:** Testing on cells, tissues, and computer models in the lab. 2. **Animal testing:** Testing on live animals to see its effect on a whole living organism. 3. **Clinical trials (human testing):** * Phase 1: Testing on a small number of **healthy volunteers** to check for safety and side effects. * Phase 2: Testing on a small number of patients with the disease to check for effectiveness. * Phase 3: Testing on a large number of patients to confirm effectiveness and monitor side effects. The question asks for the stage after animal testing, which is testing on healthy volunteers.