Introduction : Immunization is one of the most cost-effective public health investments. Before the pandemic, immunization services operated under established routines, with fixed and outreach sessions ensuring access even in remote areas. The COVID-19 pandemic disrupted this system through lockdowns, redeployment of healthcare workers, supply chain interruptions, and increased vaccine hesitancy.
Methods : Retrospective observational study was conducted using Immunization secondary data from the Tamil Nadu Health Management Information System [TN-HMIS]. The number of immunization sessions planned and held and the immunization target and coverage during Pre-Pandemic [2018-19 to 2019-20], Pandemic [2020-21 to 2021-22], and Post-Pandemic [2022-23 to 2023-24] were collected from TN-HMIS portal. Immunisation coverage represented as Full Immunisation Coverage (FIC).
RESULTS: Immunisation sessions held has decreased during early phase of pandemic and post pandemic. Gap between sessions planned is consistent during the entire period with maximum gap during early pandemic. Near approximation of sessions planned and conducted is observed during 2023-24 (during post pandemic phase). Fully immunized coverage decreased from 99% during Pre pandemic to 97% during pandemic and increased to 102% in early Post pandemic and returned to 99% during late Post pandemic 19.
CONCLUSION: There is an increase in the number of immunization sessions planned and held during pandemic and Post Pandemic. Coverage of FIC is in declining trend during pandemic phase followed by increasing trend during early part of post pandemic, followed by return to normalcy during later part of post pandemic phase.