The arrival of COVID-19 vaccines is giving the world hope of ending the pandemic, but many countries remain consumed by the virus's spread. So, as we wait for widespread availability and distribution of the vaccines, preventive health measures such as social distancing, mask-wearing and hand-washing will remain critical to containing the disease.

For some, following this guidance is not feasible. Many poor people, for example, must contend with overcrowding, limited access to clean water and soap, and the absence of robust social safety nets.

Beyond material constraints, however, lie others related to information and trust. Some may be unaware of public-health guidelines or may not understand the specific steps to follow. Misinformation about COVID-19 can undermine the recommended measures. And in some contexts, lack of confidence in the health system itself may reduce adherence to guidelines.

While biomedical researchers and public-health experts scrambled to learn about the novel coronavirus in early 2020, economists and other social scientists set to work testing COVID-19 policies and programs. The body of evidence they have developed holds important lessons for overcoming information constraints, combating misinformation, and building trust in health systems. These insights may also help to improve delivery and increase uptake of COVID-19 vaccines.

One study involved sending two-and-a-half-minute videos about COVID-19 via text message to 25 million people in West Bengal, India. The videos instructed them to report any symptoms to community health workers and emphasized the importance of adopting preventive behaviors. Recipients subsequently reported traveling less and washing their hands more often, and doubled their reporting of symptoms to health workers.

This striking result may appear surprising, given that policymakers had been sending COVID-19 prevention messages for weeks to the people who received the videos. One possible reason why the video messages proved more effective is that they provided specific, actionable information about which symptoms to look out for, and specified the steps people should take to report them and prevent disease.

Even when information is specific and actionable, outcomes may vary. One ongoing study in Uganda, for example, seeks to understand the relative effects of emphasizing individual versus societal benefits on people's adherence to COVID-19 public-health guidelines.

And what about the messenger? In the Indian study, the person providing information in the video – the Nobel laureate economist Abhijit Banerjee – was well known, and his message may thus have had an outsize impact. But that study also showed the role peers can play. Even those who did not receive the public-health messages reported increased adherence to COVID-19 guidelines as they observed and emulated their neighbors' changed behavior.

That raises the question of whether peers are more effective than a third party in influencing behavior. In Zambia, researchers are asking individuals to communicate COVID-19 health information to their family and friends via SMS, and comparing the impact on preventive behavior to the impact of messages from a central authority.

Policymakers may also need to go beyond simply communicating prevention guidelines and more proactively combat misinformation that leads to confusion and mistrust. In Zimbabwe, local organizations sent WhatsApp messages to their newsletter subscribers to convey truthful information about COVID-19 and debunk misinformation about fake cures. These messages from a trusted source increased knowledge about the disease and reduced reported harmful behavior such as violating lockdown orders.

Similarly, economists in Mexico are working with its public health institute to assess how a messenger's political leanings and credibility influence the level of trust in the message and adherence to guidelines.

The question of trust is not limited to concerns about misinformation. We learned from the 2014-16 Ebola crisis in West Africa that policies that increase confidence in the health system can improve cooperation with health guidelines, in turn leading to increased testing and reduced disease spread and mortality.

The factors helping to overcome lack of trust in a health system can vary greatly depending on the context. In the US, where health inequities across racial groups are large, a study of preventive care found that black men were more likely to trust black physicians and more likely to take up various preventive health measures, including the flu vaccine, if they consulted one.

These results were supported by a separate study in the US, which found that black adults who watched a physician-delivered video on COVID-19 prevention were more likely to seek out additional information if the physician in the video was also black.

As we enter further uncharted territory with COVID-19 vaccines, this research on how to boost adoption of preventive measures could help us understand how to increase immunization uptake. Much of the focus so far has rightly been on vaccine supply chains and distribution challenges.

But research shows that motivating people to take up a vaccine is vital even in the absence of misinformation and mistrust. Research conducted on immunization prior to the pandemic can inform our initial thinking on COVID-19 vaccination programs, and help us formulate strategies to help increase uptake.

Incorporating into public policy the lessons of economic research on the significance of how information is conveyed, and by whom, is particularly important in a context of information overload, misinformation, and mistrust of health systems. To help us move toward a post-pandemic world, policymakers should consider carefully how these findings could be used to increase uptake of COVID-19 vaccines.