Veterinary Epidemiology and Zoonosis

Evaluation of vaccines and diagnostic tests

EXERCISE-5: EVALUATION OF VACCINES AND DIAGNOSTIC TESTS

Vaccine evaluation

• Evaluation of vaccine efficiency is based on the attack rate in vaccinated and non-vaccinated groups. It is calculated by the simple formula:

• Where,
  • ARU = attack rate in unvaccinated group
  • ARV = attack rate in vaccinated group

• Measurement of vaccine efficacy from attack rate data

Disease	Vaccination status		Total
	Vaccinated	Unvaccinated
Present	a	b	a+b
Absent	c	d	c + d
Total	a+c	b+d	a+b+c+d = n

• The efficacy of the vaccine may be calculated from the above table in the following manner.

• Where, RR is the relative risk of disease in exposed and not exposed groups.