Communicating doctors' consensus persistently increases COVID-19 vaccinations.

The reluctance of people to get vaccinated represents a fundamental challenge to containing the spread of deadly infectious diseases1,2, including COVID-19. Identifying misperceptions that can fuel vaccine hesitancy and creating effective communication strategies to overcome them are a global public health priority3-5. Medical doctors are a trusted source of advice about vaccinations6, but media reports may create an inaccurate impression that vaccine controversy is prevalent among doctors, even when a broad consensus exists7,8. Here we show that public misperceptions about the views of doctors on the COVID-19 vaccines are widespread, and correcting them increases vaccine uptake. We implement a survey among 9,650 doctors in the Czech Republic and find that 90% of doctors trust the vaccines. Next, we show that 90% of respondents in a nationally representative sample (n = 2,101) underestimate doctors' trust; the most common belief is that only 50% of doctors trust the vaccines. Finally, we integrate randomized provision of information about the true views held by doctors into a longitudinal data collection that regularly monitors vaccination status over 9 months. The treatment recalibrates beliefs and leads to a persistent increase in vaccine uptake. The approach demonstrated in this paper shows how the engagement of professional medical associations, with their unparalleled capacity to elicit individual views of doctors on a large scale, can help to create a cheap, scalable intervention that has lasting positive impacts on health behaviour.

Covid-19 crisis and hostility against foreigners.

Harmful behavior against out-group members often rises during periods of economic hardship and health pandemics. Here, we test the widespread concern that the Covid-19 crisis may fuel hostility against people from other nations. Using a controlled money-burning task, we elicited hostile behavior among a nationally representative sample (n = 2,186) in the Czech Republic during the first wave of the pandemic. We provide evidence that exogenously elevating the salience of the Covid-19 crisis increases hostility against foreigners from the EU, USA and Asia. This behavioral response is similar across various demographic sub-groups. Further, we observe zero to small negative effects for both domestic out-groups and in-groups, suggesting that the salience of Covid-19 might negatively affect behavior not only towards foreigners but to other people more generally, though these findings are not conclusive. The results underscore the importance of not inflaming anti-foreigner sentiments and suggest the need to monitor impacts of the crisis on behavior in the social domain.