Associations between Covid-19 Vaccination and Fertility: Interrupted Time Series Analyses of Birth Rates for 22 Countries

Aiva Jasilioniene , Max Planck Institute for Demographic Research
Domantas Jasilionis, Max Planck Institute for Demographic Research / Vytautas Magnus University
Dmitri A. Jdanov, Max Planck Institute for Demographic Research (Germany) / National Research University Higher School of Economics (Russia)
Mikko Myrskylä, Max Planck Institute for Demographic Research and London School of Economics and Political Science (LSE)

Fertility trends underwent strong fluctuations during the COVID-19 pandemic. Upward and downward fertility shifts, although of varying size, occurred quite synchronously in many higher-income countries. This study focuses on the sharp downturn in monthly birth rates observed at the turn of the years 2021-2022, which has been puzzling in the light of the relatively stable and positive fertility dynamics during most of 2021 in many countries. This decline in births is linked with conceptions in spring-summer 2021, which coincides in time with the COVID-19 vaccination effort gathering momentum. The central aim of this study is to explore whether the rollout of COVID-19 vaccination and the fall in monthly fertility are associated. Using an interrupted time series design, the impact of two interventions – the start of the COVID-19 pandemic in March 2020 and the start of COVID-19 vaccination– on the trends in seasonally- and calendar-adjusted monthly TFRs has been evaluated. The findings suggest that at least in some countries, the COVID-19 vaccination seemingly influenced childbearing behaviour and thus contributed to the decline in birth rates seen about nine months following the start of the effort. More in-depth and context-sensitive research is needed to further explore causal mechanisms underlying changes in childbearing decisions in response to COVID-19 vaccination.

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 Presented in Session 46. COVID-19 Impact on Fertility