RESUMEN
Objective To evaluate the effectiveness and benefit of influenza vaccination among school-age children in Xining, Qinghai. Methods A total of 215 children were randomly recruited as the vaccination group and vaccinated with trivalent split influenza vaccine. At the same time, 215 healthy children (no known diseases and past history reported, and no vaccinations) who underwent physical examinations during the same period were selected as the control group. The basic demographic information was investigated and a 1-year follow-up was carried out. Results The demographic characteristics of children in the vaccinated group and the control group were not significantly different (P>0.05), and were comparable between the two groups. After four follow-up visits within one year for the enrolled children, the overall incidence of influenza-like illness in children in the vaccinated group and the control group was 7.4% (16/215) and 16.7% (36/215), respectively, and the difference was statistically significant (χ2=8.75, P2=5.03, P2=1.37, P>0.05). The protection rate was 52.6%, and the protection index was 2.11. The proportions of irrational use of antibiotics were 6.0% (13/215) and 20.9% (45/215), respectively, and the difference was statistically significant (χ2=20.41, P<0.05). The protection rate was 71.3%, and the protection index was 3.48. The per capita income from vaccination was 667.9 yuan, and the benefit-cost ratio was 9.97:1. Conclusion Influenza vaccination for school-age children can effectively prevent the incidence of influenza-like diseases and the common cold, and the vaccination is cost-effective.