Attendance and vaccination at immunization clinics in rural Gambia before and during the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic has affected the delivery of essential health services, such as routine immunization. We assessed the impact of the pandemic on the uptake of routine immunization in rural Gambia. METHODS: We collected real-time vaccine administration data in the Basse and Fuladu West Health & Demographic Surveillance Systems from September 01, 2019, to December 31, 2020. We assessed the monthly number of Expanded Program on Immunization (EPI) clinic attendances and vaccines administered, comparing data during the baseline period (September 01, 2019-March 31, 2020), COVID-19 interruption period (April 01-June 30, 2020), initial recovery period (Jul 01-September 30, 2020) and the late recovery period (October 01-December 31, 2020). RESULTS: Compared to the baseline period, there was an overall average monthly decline of 13.4% in EPI attendance and 38.3% reduction in average monthly immunizations during the interruption period. This decrease was particularly noticeable for Bacille Calmette-Guérin (BCG) (47.2%), birth dose hepatitis B (Hep B) (46.9%), 1st dose pentavalent (Penta1) (43.1%), 1st dose pneumococcal conjugate vaccine (PCV1) (42.4%), and measles vaccines (15.5%). Comparing the late recovery to baseline period, average monthly EPI attendance was 5.3% higher, with 1.9% increase in average monthly immunizations. Monthly immunizations for BCG were 3.0% greater, 2.5% greater for Hep B, 22.7% greater for oral polio vaccine (OPV1), 2.0% less for Penta1, 19.2% less for Penta2, and 2.6% less for PCV1. CONCLUSION: The reduced EPI attendance during the pandemic interruption period lasted only 3 months. Significant recovery in EPI attendance occurred during the late recovery period, while rates of monthly immunization returned to pre-pandemic levels for most antigens. EPI programmes should implement strategies to deliver missed antigens when infants do present to EPI clinics, aware that missed doses may be age dependent.