Changed Trends in Utilization and Substitution Pattern of Non-National Immunization Program Vaccines in Central China, 2011–2024

<b>Objective:</b> To explore the problems with non-National Immunization Program vaccinations in Hubei Province and to provide the basis for follow-up vaccination and management. <b>Methods:</b> Vaccination data on non-NIP/NIP vaccine doses were extracted from the Hubei Provincial Immunization Planning Information Management System. Descriptive epidemiological analyses were conducted to examine dose administration, vaccine-type composition, regional distribution, and substitution patterns. The trend χ² test was used to assess temporal significance. Multistage regression analysis was performed using Joinpoint software. <b>Results:</b> From 2011 to 2024, a total of 91,009,259 doses (annual average: 6,500,661) with 35 types of non-NIP vaccines were administered in Hubei Province, China. The top five vaccines by doses administered were influenza vaccine, rabies vaccine, Hemophilus influenzae type b conjugate vaccine, varicella attenuated live vaccine, and enterovirus 71 inactivated vaccine. Before 2024 (2011-2023), vaccine utilization showed a long-term upward trend: per 10,000, population usage rose from 657.07 (2011) to a peak of 2393.21 (2023) (Increase: 264.22%, χ² = 138.62, <i>p</i> < 0.05) (AAPC = 10.92%, <i>p</i> < 0.05) and non-NIP's share of total vaccines increased from 25.52% (2011) to 65.95% (2023), (Increase: 154.33%, χ² = 89.47, <i>p</i> < 0.05) (AAPC = 8.74%, <i>p</i> < 0.05). A notable reversal occurred in 2024. Non-NIP doses dropped from 13,971,544 (2023) to 10,238,861 (2024) with population usage falling from 2393.21 (2023) to 1755.03 (2024) (decrease: 26.66%) per 10,000, with the top three declines being in inactivated polio vaccine (IPV) (decrease: 49.53%), influenza vaccine (decrease: 44.21%), and oral rotavirus attenuated live vaccine (decrease: 43.50%). The total number of substitutive non-National Immunization Program (non-NIP) vaccine doses administered reached 16,618,755, with an overall substitution rate of 10.10%. This rate showed a steady upward trend from 5.57% in 2011 to 24.74% in 2023 (trend χ² = 15.11, <i>p</i> < 0.05), yet it increased to 28.03% in 2024. <b>Conclusions:</b> Non-NIP vaccines and NIP-substitute use grew steadily for over a decade, then contracted sharply in 2024. Decision-makers should investigate the sudden dip, differentiate discretionary from replacement demand, and reallocate funds to sustain equity and prevent further erosion of coverage.