Opposition to Voluntary and Mandated COVID-19 Vaccination as a Dynamic Process: Evidence and Policy Implications of Changing Beliefs

"Who are those resisting vaccination? Under what conditions do they change their minds?"

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. From early in the pandemic, these researchers have tracked the same individuals in Germany, providing a lens into the conditions under which people's attitudes toward voluntary and mandated vaccinations change - information for policy aiming to increase COVID-19 vaccination rates.

Each of the three cross-sections making up the panel survey (conducted in April-May 2020, October-November 2020, and May 2021) was composed of about 4,000 respondents that are representative of the German population. The panel consists of the 2,018 individuals who participated in all three waves. The German government's explicit endorsement of a voluntary-only vaccination regime did not change over the course of the three waves of the survey; only in late 2021 was a transition to greater use of mandates initiated.

The study found that only 3.3% of the panel were opposed to voluntary vaccination in all three waves of the survey, a number that the researchers demonstrate is unlikely to be the result of response error. In contrast, the fraction consistently opposed to enforced vaccinations was 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.

Analysis provided here indicates that a vaccine mandate would have had little net effect on the extent of pro or con attitudes among the undecided. Roughly half of the undecided would have remained undecided, the survey suggests, with the other half split between those who would have become opposed numbering only slightly more than those who would have responded to a mandate by switching to favouring vaccinations.

Opposition to vaccination is very widespread, particularly if mandated: 34.6% were opposed to voluntary vaccination in at least one of the survey waves, and 52.4% were opposed if vaccination were mandated. Opposition to enforced vaccinations is quite stable: The majority of those opposed in one wave remain opposed in the next. Consistent opposition is associated with lack of trust in public institutions, beliefs that the vaccines are ineffective, and trust in the German health system (presumably to take care of the respondent should they become ill). The belief in vaccine effectiveness may reflect trust in scientists (with which it is correlated in the dataset), the importance of which has also been found for other COVID-19 policies.

Implications of the results - both for the specific challenge of ending the COVID-19 pandemic and for the more general problem of policy design in novel public health emergencies with a high degree of uncertainty - include:

1. Easily accessed vaccines and convincing messaging about vaccine effectiveness and the trustworthiness of public institutions could persuade a significant number of the opposed to be vaccinated, consistent with the study's evidence on the role of changing beliefs in distinguishing between the hard-core and transient opponents. However, the data suggest that it is likely that vaccination opposition hardened in response to the increased use of de facto mandates late in 2021 and the announced prospect of general mandates in 2022.
2. For reasons outlined here, the fraction in the panel that were consistently opposed to mandated vaccinations - 16.5% - suggests that a substantial number may have to be vaccinated against their will in order to reach the target vaccination levels thought to be sufficient to contain the pandemic.
3. Consistent opposition and switching from opposition to willingness is not predicted by who one is (sociodemographically) but instead by one's beliefs and attitudes, suggesting the importance of sustaining high levels of trust in public institutions and in the effectiveness of the vaccines. Social learning mechanisms such as conformism and conditional cooperation may also be mobilised by public policy in countries where the vast majority have been vaccinated at least twice.
4. Shifting to mandates does not reduce the importance of changing beliefs through persuasion, given the limits both on a government's capacity to implement enforced vaccines and on the resources it can devote to this task.

Three final observations concern implications for the more general problem of policy design in novel public health emergencies and other societal challenges:

• Incentives and constraints remain an important policy tool, but they may be enriched by a more psychologically and sociologically informed perspective that would capture the fact that: people often act on the basis of moral and social concerns, for example, following herd behaviour due to conformism; they may not be adept at anticipating the effect of their actions on their own well-being, leading to seemingly inconsistent behaviour; and they may be slow to alter their course of action when new information is available.
• While policymakers should be concerned that mandates may crowd out intrinsic or social motivations to adhere to recommended individual behaviours, they may also aspire to design and frame policies such that constraints will crowd in these social motivations - e.g., evidence suggests that adverse effects of control can be mitigated if those subject to a constraint understand its purpose - for example, preventing free riding by others.
• The data shared here and the related literature suggest that, where mandates are to be used, resistance would be lower if those affected (i) are convinced of the severity of the problem to which the mandate is addressed, (ii) are convinced of the effectiveness of the mandated behaviour in addressing the problem, and (iii) could see the mandate as a precondition for advancing valued social norms.

In conclusion, "well-designed policies of persuasion and enforcement will be complementary, not alternatives."