Seroepidemiology of varicella-zoster virus antibody levels amongchildren aged 1 to 12 years in Lu'an City / 预防医学

ABSTRACT

Objective@#To detect varicella-zoster virus ( VZV ) antibody levels among children aged 1 to 12 years in Lu'an City, Anhui Province, so as to provide insights into perfection of the varicella immunization strategy.@*Methods@#Children aged 1 to 12 years were recruited from Lu'an City using the stratified random sampling method from July 2018 to February 2019, and subjects' demographics were collected using questionnaires. The inoculation of varicella vaccines was retrieved through the Anhui Immunization Information Management System or review of preventive immunization certificates, and the serum VZV IgG antibody was detected using enzyme-linked immunosorbent assay ( ELISA ). The seroprevalence and geometric mean concentration of the VZV-IgG antibody were estimated, and the changes of serum the VZV-IgG antibody levels were analyzed at different time intervals following varicella vaccination. @*Results@#Totally 734 children were surveyed, with a mean age of ( 6.94±2.95 ) years, and the subjects included 412 boys ( 56.13% ) and 322 girls ( 43.87% ). There were 514 children ( 70.03% ) with a history of varicella vaccination, including 501 children ( 68.26% ) with one dose of varicella vaccine and 13 children ( 1.77% ) with two doses. There were 297 children ( 40.46% ) positive for VZV-IgG antibody, with seroprevalence of 40.46%, and the GMC of VZV-IgG antibody was 74.97 ( 95%CI 65.55-85.75 ) mIU/mL. The seroprevalence of the VZV-IgG antibody were 34.55%, 42.91%, and 46.15% among the unvaccinated children and children receiving one dose and two doses of varicella vaccine, with the GMCs of 53.04, 86.31 and 114.46 mIU/mL, respectively. The mean time interval between inoculation of the last dose of varicella vaccine and blood sample collection was ( 5.21±2.79 ) years, and the lowest seroprevalene (31.48%) and GMC of the VZV-IgG antibody (49.96 mIU/mL) were found 4 years after inoculation of varicella vaccine.@*Conclusions@#The serum VZV-IgG antibody level is low among children aged 1 to 12 years in Lu'an City, and the seroprevalence of the VZV-IgG antibody is affected by age and doses of varicella vaccine. A 2-dose schedule of varicella vaccine is recommended for children.