Let's call! Using the phone to increase vaccine acceptance.

In the context of the COVID-19 pandemic, we develop and test experimentally three phone-based interventions to increase vaccine acceptance in Mozambique. The first endorses the vaccine with a simple positive message. The second adds the activation of social memory on the country's success in eradicating wild polio with vaccination campaigns. The third further adds a structured interaction with the participant to develop a critical view toward misleading information and minimize the sharing of fake news. We find that combining the endorsement with the stimulation of social memory and the structured interaction increases vaccine acceptance and trust in institutions.

Religious proximity and misinformation: Experimental evidence from a mobile phone-based campaign in India.

We investigate how religion concordance influences the effectiveness of preventive health campaigns. Conducted during the early stages of the COVID-19 pandemic in two major Indian cities marked by Hindu-Muslim tensions, we randomly assigned a representative sample of slum residents to receive either a physician-delivered information campaign promoting health-related preventive practices, or uninformative control messages on their mobile phones. Messages, introduced by a local citizen (the sender), were cross-randomized to start with a greeting signaling either a Hindu or a Muslim identity, manipulating religion concordance between sender and receiver. We found that doctor messages increased compliance with recommended practices and beliefs in their efficacy. Our findings suggest that the campaign's impact is primarily driven by shared religion between sender and receiver, leading to increased message engagement and compliance with recommended practices. Additionally, we observe that religion concordance helps protect against misinformation.

COVID-19 vaccine acceptance and hesitancy in low- and middle-income countries.

Widespread acceptance of COVID-19 vaccines is crucial for achieving sufficient immunization coverage to end the global pandemic, yet few studies have investigated COVID-19 vaccination attitudes in lower-income countries, where large-scale vaccination is just beginning. We analyze COVID-19 vaccine acceptance across 15 survey samples covering 10 low- and middle-income countries (LMICs) in Asia, Africa and South America, Russia (an upper-middle-income country) and the United States, including a total of 44,260 individuals. We find considerably higher willingness to take a COVID-19 vaccine in our LMIC samples (mean 80.3%; median 78%; range 30.1 percentage points) compared with the United States (mean 64.6%) and Russia (mean 30.4%). Vaccine acceptance in LMICs is primarily explained by an interest in personal protection against COVID-19, while concern about side effects is the most common reason for hesitancy. Health workers are the most trusted sources of guidance about COVID-19 vaccines. Evidence from this sample of LMICs suggests that prioritizing vaccine distribution to the Global South should yield high returns in advancing global immunization coverage. Vaccination campaigns should focus on translating the high levels of stated acceptance into actual uptake. Messages highlighting vaccine efficacy and safety, delivered by healthcare workers, could be effective for addressing any remaining hesitancy in the analyzed LMICs.