Exploring Varicella Vaccine Coverage and Influencing Factors in Rural and Pastoral Children of Qinghai Province: A Cross-Sectional Catch-Up Vaccination Study

<i>Background: </i>Varicella is a respiratory infectious disease caused by varicella-zoster virus (VZV) infection. Varicella vaccine has been shown to be highly effective in preventing varicella disease, however it is not included in Qinghai Province’s local immunization planning program and must be paid for by families. Its use in local areas is options instead of compulsory, so high coverage is difficult to guarantee. Starting in October 2021, one dose of live attenuated varicella vaccine was recommended at lest for 3-17-year-old children in Qinghai. In 2022, it was conducted that an investigation of varicella vaccine coverage and factors influencing coverage among children in rural rural and pastoral areas to determine the impact of this VarV catch-up policy. <i>Objective: </i> To explore varicella vaccine coverage and factors influencing caverage among 3-17-year-old children in rural and pastoral areas of Qinghai province. <i>Methods:</i> A stratified cluster sampling method was used to select children aged 3-17 years from kindergartens and primary /secondary schools in rural and pastoral areas of Qinghai province for a questionnaire-based survey of their guardians. Coverage levels of one and two doses of VarV (VarV<sub>1</sub> and VarV<sub>2</sub>) before and after a catch-up vaccination activity initiated in October 2021, and identified factors influenceing VarV<sub>1</sub> coverage. <i>Results:</i> VarV<sub>1</sub> and VarV<sub>2 </sub>coverage levels after the catch-up activity were 79.06% (676/855) and 43.79% (363/829), respectively, and increased by 34.38 and 24.13 percentage points compared with before the catch-up activity. Multivariate logistic regression showed that VarV<sub>1 </sub>coverage was higher in rural areas than in pastoral areas (OR=4.63, 95%<I>CI</I>: 2.91-7.39), and higher among children whose guardians scored 4-6 or 7-10 points on knowledge about varicella and VarV than among children whose guardians scored 0-3 points (OR=8.61, 95%<I>CI</I>: 4.73-15.69, OR=2.86, 95%<I>CI</I>: 1.69-4.84). the main reasons for non-vaccination were guardians’ lack of understanding of VarV (48.6%, 87 children), guardians’ unawarness of the need for VarV vaccination (43.6%, 78 children), and unavailability of VarV at vaccination centers (31.3%, 56 children). <i>Conclusions: </i>The catch-up activity significantly increased VarV coverage among children in the surveyed areas. It should been strengthened that health education on knowledge about varicella and VarV among guardians of children in Qinghai, especially in pastoral areas, to promote VarV vaccination of age-eligible children.