BackgroundThere is increasing evidence that the COVID-19 pandemic disrupted childhood immunization services. However, detailed reports on immunizations and preventive antimalarial prophylactic treatments delivered and how the trends changed in referral centers in low-income countries are still missing.MethodsWe performed a retrospective cross-sectional study. Data for vaccinations administered to children <5 years of age, according to the local vaccination schedule, were extracted from the official records of the Kent Community Health Post, Sierra Leone, in the period between April 2019 and March 2021. We compared the vaccinations performed in the first year, considered as a pre-Covid period, with the second year, post-Covid period. Both the period was then divided in four trimester each and the same analysis was operated for each trimester. A Chi-square goodness of fit test was performed to compare the number of vaccinations performed both in the 2 years and in the 8 trimesters.FindingsSeven thousand two hundred and eighty-three vaccinations were administered: 4,641 in the period between April 2019 and March 2020 and 2,642 between April 2020 and March 2021. The drop in immunizations performed began as soon as the first cases were described in China. The drops were statistically significant when the first three trimesters of the two study periods were compared, while no statistically significant differences were observed for all the vaccines performed in the 4th trimesters. Vaccines administered at birth (BCG) were less affected compared to booster vaccinations.ConclusionsImmunizations administered in a referral health center in Sierra Leone significantly declined during the pandemic. Although the decline was less pronounced in the last months of the pandemic, we don't think that the small increase would indicate the recovery of previously missed vaccinations. These findings open new public health challenges for the coming years.