Table 1.

Stages of vaccine development and testing (T. N. Times, 2020).

Step 1	Preclinical Test	A vaccine to animals such as mice or monkeys to see if it produces an immune response.
Step 2	Phase I Safety Trials	vaccine is given to a small number of people to test safety and dosage as well as to confirm that it stimulates the immune system
Step 3	PHASE II Expanded Trials	Vaccine is given to hundreds of people including children and adults to see if it acts differently in them. Further, this trial checks the vaccine's safety and ability to stimulate the immune system.
Step 4	PHASE III Efficacy Trials	Vaccine is given to thousands of people and wait to see how many become infected, compared with volunteers who received a placebo. These trials can determine if the vaccine protects against the coronavirus
Step 5	Approval	Regulators in each country review the trial results and decide whether to approve the vaccine or not. During a pandemic, a vaccine may receive emergency use authorization before getting formal approval.