Assessment of Pertussis Vaccine Protective Effectiveness in Children in the Amhara Regional State, Ethiopia

Table 4

Adjusted estimates of pertussis vaccine protective effectiveness among different age categories.

Variable		Vaccinated	Un-vaccinated	Adjusted vaccine effectiveness, % (95% CI)	value
		pertussis positive/negative	pertussis positive/negative
Age (years)	6	6/25	16/33	50 (42.8–56.6)	0.65
	7	7/20	19/36	34 (28.6–40.4)
	8-9	22/32	49/70	2 (1.2–3.4)