Indian School of Business, Hyderabad, India.
Department of International Economics, The Graduate Institute, Geneva, Switzerland.
Vaccine. 2022 Nov 15;40(48):6924-6930. doi: 10.1016/j.vaccine.2022.10.024. Epub 2022 Oct 22.
India has experienced a substantial increase in the coverage of routine childhood vaccines in recent years. However, a large fraction of these vaccines is not delivered in a timely manner, i.e., at the recommended age. Further, substantial disparities exist in both coverage and timeliness across states. We aim to quantify the changes in coverage and timeliness of routine childhood vaccination in India over time, their variation across states, and changes in these variations over time.
We used data from two rounds of India's National Family Health Surveys, NFHS-3 (2005-06) and NFHS-4 (2015-16) on bacille Calmette-Guerin vaccine (BCG), three doses of diphtheria, pertussis, and tetanus vaccine (DPT1, DPT2, DPT3), and measles-containing vaccine (MCV). We used the Turnbull estimator to estimate the cumulative distribution function (CDF) of administering each vaccine by a certain age while accounting for two-sided censoring in the survey data. We then used these estimated CDFs to calculate coverage and timeliness at the national and state levels.
At the national level, both vaccination coverage and timeliness estimates increased from NFHS-3 to NFHS-4 for all vaccines. The increase in timeliness ranging from 27.3% for DPT3 to 74.0% for MCV continued to be lower than coverage, ranging from 75.3% (95% CI 57.7-87.2) for DPT3 to 74.0% (95% CI 42.2-33.0) for MCV, for all vaccines. Cross-state variation in timeliness was greater than the variation in coverage. Variation in both timeliness and coverage reduced from NFHS-3 to NFHS-4. However, this reduction was greater for timeliness than for coverage.
A large fraction of the children in India receive vaccines later than the recommended age thereby keeping them exposed to vaccine-preventable diseases. Interventions that specifically focus on improving the timely delivery of vaccines are needed to improve the overall effectiveness of the routine immunization program.
近年来，印度常规儿童疫苗的覆盖率有了大幅提高。然而，其中很大一部分疫苗没有及时接种，即在推荐的年龄。此外，各州之间在覆盖率和及时性方面存在很大差异。我们旨在随着时间的推移，定量评估印度常规儿童疫苗接种的覆盖率和及时性的变化，以及各州之间的差异变化。
我们使用了两轮印度国家家庭健康调查（NFHS）的数据，NFHS-3（2005-06 年）和 NFHS-4（2015-16 年），涉及卡介苗（BCG）、三剂白喉、百日咳和破伤风疫苗（DPT1、DPT2、DPT3）和麻疹疫苗（MCV）。我们使用特恩布尔估计量来估计在一定年龄时接种每种疫苗的累积分布函数（CDF），同时考虑到调查数据中的双侧删失。然后，我们使用这些估计的 CDF 来计算国家和州一级的覆盖率和及时性。
在国家层面，所有疫苗的接种覆盖率和及时性估计值都从 NFHS-3 增加到 NFHS-4。从 DPT3 的 27.3%到 MCV 的 74.0%的及时性增加仍然低于覆盖率，从 DPT3 的 75.3%（95%CI 57.7-87.2）到 MCV 的 74.0%（95%CI 42.2-33.0），所有疫苗都是如此。及时性的州际差异大于覆盖率的差异。从 NFHS-3 到 NFHS-4，及时性和覆盖率的变化都有所减少。然而，这种减少在及时性方面比在覆盖率方面更为明显。
印度很大一部分儿童接种疫苗的时间晚于推荐年龄，从而使他们面临疫苗可预防疾病的风险。需要采取专门针对提高疫苗及时接种的干预措施，以提高常规免疫计划的整体效果。
