Exploring associations between the Covid-19 vaccination campaign and fertility trends: a population-level analysis for 22 countries

At the turn of 2021-2022, monthly birth rates declined in many higher-income countries. We explore how COVID-19 vaccination was associated with this decline. Using an interrupted time series design, we evaluate the impact of the onset of the COVID-19 pandemic and the start of COVID-19 vaccination on seasonally-adjusted monthly total fertility rates in 22 high-income countries. Our findings show that the start of the pandemic had an immediate effect on fertility in most countries, although the size and direction of level changes considerably varied. The impact of COVID-19 vaccination was less all-embracing. A negative association between the COVID-19 vaccine rollout and fertility nine months later was found for ten out of 22 studied countries. For several countries, the decline was preceded by fertility increase that took place after the onset of the pandemic. Only four out of 22 countries had post-vaccination fertility declines that resulted in fertility being on a lower level than what the pre-pandemic trend predicted. Additional controlling for youth unemployment, stringency index, and vaccination coverage changed the associations only little. The COVID-19 vaccination campaign contributed to the variation in the short-term fertility trends. Fertility appeared to have responded in short run to vaccination, however, the resulting decline returned fertility closer to the pre-pandemic trend in most cases, and only in few countries, fertility dropped below the pre-pandemic trend.