Live vaccines are usually more potent than inactivated vaccines. They multiply within the host and produce more antigens. Usually one dose of live vaccine is enough for immunity. Some, as in the case of polio, need more. These should be spaced out.
Effective storage is crucial for live vaccines.
Do not receive vaccination from a centre that you suspect has poor storage facility. Inactivated or Killed Vaccine Certain organisms when killed by heat or chemicals and then introduced into the body induce immunity. Killed vaccines are not as effective as live vaccines. Inactivated vaccines may require two or three doses. These are administered by injections.