Regional difference on rotavirus vaccine coverage in children with diarrhea in Mozambique, before and during COVID-19 pandemic: a cross-sectional analysis.

Background: Immunization coverage is a global concern for the Immunization Agenda 2030 due to the Coronavirus disease (COVID-19) pandemic. Prior to the pandemic, Mozambique had a positive impact on reducing all-cause diarrhea hospitalization and rotavirus positivity due to vaccination with the monovalent vaccine against rotavirus (Rotarix). We evaluated rotavirus vaccine coverage in Mozambican children with diarrhea in four sentinel sites before and during the COVID-19 pandemic.

Methods: A cross-sectional analysis between January 2016 and April 2023 was performed using the National Diarrhea Surveillance data from four sentinel sites for children under five years old. The cut-off before and during the COVID-19 period was the date of the first COVID-19 case reported in Mozambique on March 22, 2020. Vaccination cards were used to verify rotavirus immunization status. A two-sample test for equality of proportions of rotavirus coverage before and during the COVID-19 pandemic was performed.

Results: During the COVID-19 pandemic, the rotavirus vaccine coverage was 77.3% (133/172), significantly higher than the 68.6% (771/1124) before the pandemic [difference: 8.7% (95% CI: 1.6 to 15.9); p-value = 0.026]. The two sample test for equality of proportions indicates that at the sentinel site in Zambézia province in the center region of the country, the rotavirus vaccine coverage reduced significantly during the pandemic period compared to the pre COVID-19 pandemic period (difference: -28.1%; 95% CI: -47.8 to -8.3; p-value = 0.028).

Conclusion: Despite national level increase of the rotavirus vaccine coverage, during the COVID-19 pandemic, there was a significant reduction in the sentinel site in the center region of the country. Future rotavirus interventions should target areas with lowest rotavirus vaccine coverage, also, rotavirus diarrheal cases and severity should be monitored in those settings to evaluate the interventions impact.