The varicella vaccination pattern among children under 5 years old in selected areas in China.

BACKGROUND: Vaccine is the most effective way to protect susceptible children from varicella. Few published literature or reports on varicella vaccination of Chinese children exist. Thus, in order to obtain specific information on varicella vaccination of this population, we conducted this survey.

METHODOLOGY: We first used purposive sampling methods to select 6 provinces 10 counties from eastern, middle and western parts of China with high quality of Immunization Information Management System (IIMS), and then randomly select children from population in the IIMS, then we checked vaccination certificate on-site.

PRINCIPAL FINDINGS: Based on the varicella vaccination information collected from 481 children's vaccination certificates from all ten selected counties in China, overall coverage of the first dose of varicella vaccine was 73.6%. There is a positive linear correlation between per capita GDP and vaccine coverage at county level (r=0.929, P < 0.01). The cumulative vaccine coverage among children at 1 year, 2 years and ≥3 years old were 67.6%, 71.9% and 73.6% respectively (X2=4.53, P =0.10). The age of vaccination was mainly concentrated in 12-17 months.

CONCLUSIONS: The coverage rate of the first dose of varicella vaccine in selected areas was lower than that recommended by WHO position paper. The coverage rate was relatively low in areas of low social-economic status. The cumulative coverage had no significant statistical difference among different age group. Most children received varicella vaccine before 3 years old. We suggest introducing the varicella vaccine into routine immunization program, to ensure universal high coverage among children in China. We also suggest that varicella vaccination information should be checked before entering school, in order to control and prevent varicella outbreaks in schools.