Effectiveness of varicella vaccine:a case-control study / 中华微生物学和免疫学杂志

ABSTRACT

Objective To evaluate the vaccine effectiveness ( VE) in children who received one dose of live attenuated varicella vaccine. Methods A questionnaire-based 1 ∶ 2 matching case-control study was conducted during May, 2015 to April, 2016 to evaluate the VE based upon the demographic data, vacci-nation status and clinical symptoms of 127 children with varicella and 254 healthy subjects under 12 years old. Results Compared with the healthy subjects, 83. 46% of the patients with varicella were immunized with one dose of varicella vaccine, which was lower than that of the control group (90. 55%) (χ2=4. 08, P<0. 05). The overall protective rate of one dose of varicella vaccine reached 64. 29% (95% CI:42. 00%-78. 00%). Of the 127 cases of varicella, 83. 46% were breakthrough cases immunized with one dose of var-icella vaccine. Primary cases presented more severe clinical symptoms than breakthrough cases. The longer the interval between vaccination and varicella-zoster virus infection was, the more severe the breakthrough cases would be. Conclusion Varicella vaccine is effective for preventing varicella, but the VE of one dose of varicella vaccine is limited. A two-dose varicella vaccination strategy should be proposed in our country as soon as possible.