Opposition to voluntary and mandated COVID-19 vaccination as a dynamic process: Evidence and policy implications of changing beliefs

COVID-19 vaccination rates slowed in many countries during the second half of 2021, along with the emergence of vocal opposition, particularly to mandated vaccinations. Who are those resisting vaccination? Under what conditions do they change their minds? Our three-wave representative panel survey from Germany allows us to estimate the dynamics of vaccine opposition, providing the following answers. Without mandates, it may be difficult to reach and to sustain the near-universal level of repeated vaccinations apparently required to contain the Delta, Omicron, and likely subsequent variants. But mandates substantially increase opposition to vaccination. We find that few were opposed to voluntary vaccination in all three waves of the survey. They are just 3.3% of our panel, a number that we demonstrate is unlikely to be the result of response error. In contrast, the fraction consistently opposed to enforced vaccinations is 16.5%. Under both policies, those consistently opposed and those switching from opposition to supporting vaccination are sociodemographically virtually indistinguishable from other Germans. Thus, the mechanisms accounting for the dynamics of vaccine attitudes may apply generally across societal groups. What differentiates them from others are their beliefs about vaccination effectiveness, their trust in public institutions, and whether they perceive enforced vaccination as a restriction on their freedom. We find that changing these beliefs is both possible and necessary to increase vaccine willingness, even in the case of mandates. An inference is that well-designed policies of persuasion and enforcement will be complementary, not alternatives.

The challenge of the first half-year of most COVID-19 vaccination campaigns was the supply of vaccines, not demand for them. It then appeared that, once vaccines were widely available, vaccination rates would approach the two-thirds level initially thought to be sufficient to control the pandemic. But the Delta and then Omicron variants along with substantial and persistent reported opposition to vaccination have raised doubts about whether vaccine willingness will be sufficient. In response, by the end of 2021, vaccination mandates were being widely adopted by governments, businesses, and educational institutions, and universal mandates were being considered and implemented (1–8).The appropriate strategies for raising vaccination rates depend on the target rate, on how many are unlikely to be vaccinated willingly in a sufficiently timely manner, on the conditions under which opponents change their minds, and on the effect of the policies themselves on vaccination preferences. Our study sheds light on the behavioral side of this evaluation.