人間行動学：COVID-19ワクチンの接種状況による差別

People who are vaccinated against COVID-19 show more negative attitudes towards unvaccinated individuals than unvaccinated individuals direct towards vaccinated individuals, suggests an assessment of more than 15,000 people from 21 countries published in Nature. These results demonstrate how individuals who comply with with the advice of health authorities react with discriminatory attitudes towards those whom they perceive to be threatening public health. The authors conclude that this behaviour may hamper pandemic management and leave some societies more divided than they were before the pandemic.

The deployment of vaccines against SARS-CoV-2 has created divides between individuals who comply with vaccination rollouts, and those who are hesitant and remain unvaccinated. Research suggests that vaccinated individuals may condemn individuals who are unvaccinated for not following the advice of health authorities. Conversely, those who refuse vaccines report that they feel discriminated against and pressured against their will (by strict government policies against unvaccinated individuals, for example), and there have been disruptive protests against vaccine mandates.

To investigate the nature and level of prejudice across groups defined by COVID-19 vaccination status, Michael Bang Petersen and colleagues assess the attitudes of 15,233 individuals (sampled to be representative of their country) covering a diverse set of cultures across the world. The authors include representative data from low- and middle-income countries, along with those from high-income countries. They report that vaccinated people express discriminatory attitudes towards individuals who are unvaccinated at levels as high as or higher than discriminatory attitudes directed towards other common targets of prejudice, such as immigrant populations or people who struggle with drug addiction. On the whole, this prejudice tends to be one-sided; only in the USA and Germany do the authors find that unvaccinated individuals feel some antipathy towards those who are vaccinated, although no statistical evidence of negative stereotyping or exclusionary attitudes towards these latter individuals was observed.

The observation that vaccinated individuals discriminate against those who are unvaccinated, but that there is no evidence for the reverse, is consistent with work on the psychology of cooperation, the authors note. Indeed, vaccinated individuals in cultures with stronger cooperative norms are shown to react more negatively against those who are unvaccinated. The authors suggest that authorities should seek to avoid fuelling deep animosity between citizens when managing large social crises, such as the COVID-19 pandemic.