Abstract

Background: Childhood immunisation is a major public health intervention for preventing vaccine-preventable diseases. However, incomplete vaccination, delayed doses and geographical disparities may leave children susceptible to infections. Population surveys and public health surveillance reports provide complementary information for assessing immunisation coverage and documented disease events without collecting new laboratory data. Objective: To assess childhood immunisation indicators in Fatehpur district, Uttar Pradesh, using National Family Health Survey (NFHS-4 and NFHS-5) data and examine the relevance of reported infectious-disease events documented by the Integrated Disease Surveillance Programme (IDSP). Methods: A descriptive secondary-data analysis was designed using published NFHS district indicators and official IDSP weekly outbreak reports. Vaccination coverage indicators were compared between NFHS-4 (2015–2016) and NFHS-5 (2019–2021), where available. Absolute differences were calculated in percentage points. IDSP reports were reviewed for documented chickenpox outbreaks in Fatehpur in May 2022 and June 2023. No primary patient data, new laboratory investigations or identifiable medical records were used. Results: Full immunisation coverage among children aged 12–23 months increased from 48.4% in NFHS-4 to 55.7% in NFHS-5, an increase of 7.3 percentage points. BCG coverage increased from 87.0% to 90.0%, while coverage with three doses of pentavalent or DPT vaccine increased from 68.7% to 76.0%. Coverage with three doses of polio vaccine declined from 63.8% to 61.8%, and first-dose measles-containing vaccine coverage remained at 71.5%. NFHS-5 reported that 29.3% of children aged 24–35 months had received a second dose of measles-containing vaccine, while 20.2% of children aged 12–23 months had received three doses of rotavirus vaccine. IDSP reported three chickenpox cases in Fatehpur in May 2022, including one sample positive for varicella-zoster virus IgM by ELISA. A separate report in June 2023 documented five chickenpox cases; the available report did not establish laboratory confirmation of varicella in those cases. Conclusion: Although full immunisation coverage improved between the two NFHS rounds, important gaps remained in selected vaccine indicators. The documented chickenpox events illustrate the importance of disease surveillance, but the available records cannot establish a causal relationship between vaccination coverage and outbreak occurrence. Improved coverage monitoring, timely completion of vaccine schedules and better linkage of immunisation and surveillance data are recommended.