. Author manuscript; available in PMC: 2015 Dec 9.

Published in final edited form as: Pediatr Infect Dis J. 2014 Nov;33(11):1164–1168. doi: 10.1097/INF.0000000000000444

TABLE 2.

Varicella Vaccine Effectiveness Against All Varicella and Moderate/Severe Varicella in Public School Students of West Virginia, 2010–2011

	Cases, n (%)	Controls, n (%)	VE (95% CI)	P Value
All varicella cases and matched controls	N = 133	N = 365
Unvaccinated	57 (42.9)	36 (9.9)	Reference
1-dose	56 (42.1)	181 (49.6)	83.2 (69.2–90.8)	<0.001
2-dose	20 (15.0)	148 (40.6)	93.9 (86.9–97.1)	<0.001
Incremental (1-dose recipients as reference)			63.6 (32.6–80.3)	0.001
Moderate/severe cases and matched controls	N = 77	N = 216
Unvaccinated	43 (55.8)	24 (11.1)	Reference
1-dose	28 (36.4)	107 (49.5)	88.2 (72.7–94.9)	<0.001
2-dose	6 (7.8)	85 (39.4)	97.5 (91.6–99.2)	<0.001
Incremental (1-dose recipients as reference)			78.6 (40.9–92.3)	0.003

VE indicates vaccine effectiveness; 95% CI, 95% confidence interval.