Age-Appropriate Immunization (AAI) as an Intractable Issue Subsequent to Coverage

Abstract

Background: Age appropriate immunization (AAI) observed as an important issue irrespective of vaccine coverage. Aim: To study the extent of AAI in a state with high coverage for fully immunized (FI) coverage. Subjects and Methods: A rapid cross-sectional survey was done in all 12 districts of Himachal Pradesh, India using World Health Organization (WHO) approved 30 cluster techniques in every district. Mean age (in days) with 95.0% confidence interval (CI) was calculated to ascertain gap between vaccines; BCG, DPT/Hep B (1,2,3) and measles. Results: About 82.0% mothers possessed immunization card of 2491 surveyed children and coverage was found to be 84.9% for both BCG and DPT/Hep B-1, and 84.8%, 83.9%, and 82.7% for DPT/Hep B-2, 3 and measles respectively. The mean age of immunization observed to be 21.0 (95.0% CI: 19.1- 22.8) for BCG, 76.5 (95.0% CI: 73.8-79.4) for DPT/Hep B-1, 112.4 (95.0% CI: 109.3-115.5) for DPT/ Hep B-2, 148.0 (95.0% CI: 144.8-151.3) for DPT/Hep B-3, and 302.7 (95.0% CI: 299.5-305.6) days for measles. Mean gap in days between vaccines was observed as 58.1 (95.0% CI: 55.4-60.8) between BCG and DPT/Hep B-1, 42.6 (95.0% CI:40.4-44.7), 44.2 (95.0% CI:42.3-46.5), and 162.1 (95.0% CI: 159.3-164.8) between DPT/Hep B-1 and 2, DPT/Hep B-2 and 3, and DPT/Hep B-3 and measles respectively. Variation across districts was also observed for mean age of immunization and gap between vaccines. Conclusion: AAI observed as a public health issue adjunct to vaccination coverage in order to improve the quality of immunization services.

Keywords: Age appropriate immunization, Mean age