TABLE 1.

Demographic and Vaccination Characteristics Among Cases and Controls in Public School Students of West Virginia, 2010–2011

	Cases (N = 133), n (%)	Controls (N = 365), n (%)	P Value
Age in years: mean (range)	10.8 (5.3–18.0)	10.5 (5.4–18.7)	0.27
Years since last dose of varicella vaccine: mean (range)	7.5 (0.7–14.4)	5.7 (0.1–14.7)	<0.001
Age in months at receipt of first dose varicella vaccine: mean (range)	24.0 (12.2–139.5)	29.1 (12.0–165.1)	0.12
Age in years at receipt of second dose of varicella vaccine: mean (range)	6.2 (2.6–13.4)	8.2 (1.5–15.3)	0.007
Years between first and second dose: mean (range)	4.9 (1.6–12.1)	6.1 (0.2–13.4)	0.09
Sex			0.58
Male	70 (52.6)	182 (49.9)
Female	63 (47.4)	183 (50.1)
Vaccination status			<0.001
Unvaccinated	57 (42.9)	36 (9.9)
1-dose	56 (42.1)	181 (49.6)
2-dose	20 (15.0)	148 (40.6)
Received first dose of varicella vaccine at <15 months of age	42 (55.3)	158 (48.0)	0.31
Received second dose of varicella vaccine at age <6 years	12 (60.0)	49 (33.1)	0.03