Missed opportunities for maternal immunisation against influenza and COVID-19, Norway, October 2023 to May 2024: a population-based registry study

BACKGROUNDPregnant women and their newborns are at increased risk of severe outcomes from influenza and COVID-19 infections; maternal vaccination is recommended. However, no routine surveillance of maternal vaccine coverage exists in Norway.AIMTo provide insights into vaccination coverage and timing during pregnancy.METHODSThis population-based registry study included women who gave birth in Norway during 1 October 2023-30 September 2024. Data on influenza and COVID-19 vaccinations administered during 1 October 2023-10 May 2024 were obtained from the national immunisation registry and linked to birth data from the Medical Birth Registry Norway. Cumulative coverage included vaccines administered during pregnancy, with sub-analyses focusing on second and third trimester vaccinations, month of delivery and maternal age.RESULTSOverall influenza vaccination coverage was 29.9% (15,915/53,161), with 22.3% (11,856/53,161) vaccinated in the second or third trimester. Coverage increased from 16.4% (7,287/44,454) in October to 26.4% (12,982/49,170) in November and plateaued thereafter. Coverage peaked among women delivering in February (50.8%; 2,159/4,248) and declined afterwards. COVID-19 vaccination coverage was 12.1% (6,423/53,161) with 10.1% (5,349/53,161) in the second or third trimester, following a similar pattern to influenza. Overall, 11.4% received both vaccines. The lowest uptake (< 19%) was among women aged 25 years or younger.CONCLUSIONCoverage of maternal influenza and COVID-19 vaccinations for 2023/24 remained low, with missed opportunities to reach pregnant women beyond November 2023. Overall, the coverage was lowest among women aged 25 years or younger. Strengthened efforts are needed to increase vaccination coverage among pregnant women and reduce gaps in protection.