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Please note: This document was prepared by the J-PAL Health sector to provide recommendations for addressing Covid-19 immunization. It is not an exhaustive review of all the rigorous evidence on the discussed topics.
Last updated: January 2023
Vaccines are one of the most impactful and cost-effective public health commodities, responsible for protecting millions of people every year against various infectious diseases such as polio, measles, and, most recently, Covid-19.1 Despite major accomplishments, Covid-19 vaccine campaigns continue to face challenges as of early 2023–two years after the first vaccines were approved. Coverage remains low globally, especially in low- and middle-income countries with only 26.4 percent of people in low-income countries having received at least one dose of the vaccine while high-income countries have 79.7 percent coverage as of January 2023.2
Many governments, global health organizations, civil society members, and more have ramped up, and tried to sustain, Covid-19 vaccination efforts with an eye toward reducing hospitalizations and deaths. COVAX, coordinated by Gavi, the Vaccine Alliance, the Coalition for Epidemic Preparedness Innovations, and the World Health Organization (WHO), has served as a groundbreaking global effort to accelerate the development, production, and equitable distribution of the vaccines. Building off the work of COVAX, the Covid-19 Vaccine Delivery Partnership, launched in early 2022, focuses on accelerating vaccine coverage in the countries with the lowest vaccination rates.3 As of January 2023, 13.24 billion doses of Covid-19 vaccines have been administered globally.4
Inequitable distribution of vaccines globally has prevented widespread access to Covid-19 vaccines, particularly in many low- and middle-income countries.5,6 In many instances, vaccine hesitancy or refusal is also present.7,8,9,10,11 Vaccination campaigns should not only account for logistics and service delivery challenges but also aim to strengthen the public’s demand for Covid-19 immunization.12
This note provides an overview of policy lessons stemming from economic research on improving Covid-19 immunization coverage and focuses on strategies to strengthen demand. For lessons on increasing routine child immunization coverage, please see the brief available here.
This note does not tailor recommendations to specific contexts or provide details on implementation. Rather, we encourage policymakers to reach out to Emily Blagg, a senior policy associate with J-PAL's Health sector, for follow-up conversations on incorporating the evidence into policy decisions.
Even when vaccines are readily available and provided free of charge, several factors may make it difficult for caregivers to vaccinate their children or for adults to get vaccinated against Covid-19. Such barriers include lack of or inaccurate information, lack of trust, the low private benefits of immunization relative to the overall societal gains from herd immunity, and behavioral biases. Well-designed information campaigns, nudges, small incentives, and trust-building policies can address these barriers and increase demand for immunizations.
People may not be willing to seek out health services or take up preventive behaviors because of a lack of accurate information, information not being salient, or entrenched social norms. Information provision can help in overcoming these barriers to uptake of health products and services. In the case of Covid-19, information provision may be especially important given the novelty of the disease and associated treatments and vaccines.
A large body of evidence from around the world shows that peers and community members can influence behavior.16 For immunization, peers can be leveraged to diffuse key logistical information such as when and where services are available or the presence of incentives, should those be in place. Spreading messages via peers can also increase demand by sharing information about the benefits of immunization or keeping immunization top of mind. Additionally, simply knowing that others in the community are engaging in certain health activities or adhering to preventive measures, like vaccination, may influence individuals to either act similarly and increase their willingness to get vaccinated, or it may have the opposite impact causing individuals to decrease their vaccine willingness and instead encourage them to “free ride” on the safety provided by others’ actions.
Policymakers may want to consider leveraging peers and other members of social networks to promote Covid-19 vaccination. Importantly, research on childhood immunizations has shown that simply asking a few community members to name well-connected individuals can be an inexpensive and accurate way to identify promising individuals to include in community-level immunization promotion.17
Because of larger networks, role modeling, ease of information sharing, and more, influential individuals, such as celebrities or experts, can help diffuse knowledge and combat misinformation on key health issues.20 However, influential individuals can also be a source of misinformation, and particularly polarizing or political individuals could potentially have negative impacts.
Policymakers may want to consider leveraging celebrity or expert outreach to increase knowledge about immunization. Knowledge about the importance of immunization is a critical step in motivating take-up; however, the extent to which increased knowledge translates into actual immunization improvements may be limited in contexts where other important barriers remain.
Nudges are light-touch interventions that address behavioral biases such as impatience, procrastination, or demand for convenience. They can help make immunization more salient and, in some cases, provide information. Nudges can take multiple forms, such as text message reminders and prompts at the pharmacy or doctor’s office. The design of nudges is particularly important for their efficacy.
Policymakers may want to consider using nudges for immunization to reach individuals who may be indifferent to immunization; however, they are unlikely to influence those who are hesitant or opposed to vaccines. For nudges providing information, specific and actionable guidance is important to promote behavioral change.22 Additional message framings, such as emphasis on prosocial behavior or personal benefits as well as nudge frequency, can also impact the effectiveness of information dissemination and nudges depending on the context.
Small incentives can help overcome behavioral biases such as procrastination and increase the immediate perceived benefit of receiving a vaccine.27 By improving immunization demand, these incentives can amplify the impact of investments in vaccine delivery. Although incentives may go to those who would have been vaccinated without incentives, in some contexts the cost per child has fallen when incentives were introduced by spreading fixed costs over a larger number of recipients.28
Policymakers may want to consider creating small incentives that signal progress through the immunization schedule. In the context of Covid-19, such progressive incentives could be especially relevant for multidose vaccines and recommended boosters. Small incentives are unlikely to overcome strong opposition to immunization but rather may be more effective for those who procrastinate, are ambivalent about being vaccinated, or are slightly hesitant to do so. However, incentives may, in some cases, actually decrease vaccination rates as the public might feel unwanted pressure to vaccinate or become skeptical of why they are being paid for a medical procedure. For instance, in the aforementioned California study,29 among vaccine-hesitant individuals presented with $10 or $50 financial incentives, those over forty years old became less likely to get vaccinated.
Low confidence in health systems could stem from a variety of factors, including low-quality care, negative experiences with the health system, discrimination, or a lack of information.
Policymakers may want to consider implementing trust-building interventions to increase vaccine take-up in instances where marginalized groups may be less willing to get vaccinated or past events have undermined confidence in health care. Such policies will look different depending on the context but could include the ability to see health providers from the same race or implementing accountability mechanisms and other quality improvements. Given that low-quality care can contribute to low confidence in health systems, supply-side investments may have additional benefits to vaccine demand.30
The majority of these research studies test one type of intervention at a time without comparing these different interventions or testing them in combination with one another. Given the variety of barriers to vaccination, multiple interventions may be needed to maximize overall effectiveness, leading to the largest increase in immunization, however, additional research is needed on this topic.
This evidence note provides an overview of policy lessons stemming from the economic research thus far on improving Covid-19 vaccine coverage. However, there is still a need for further randomized evaluations on improving the availability and accessibility of vaccines as well as increasing their demand to inform policy decisions.
The Abdul Latif Jameel Poverty Action Lab (J-PAL) is a global research center working to reduce poverty by ensuring that policy is informed by scientific evidence. Anchored by a network of more than 750 affiliated researchersStrengthening immunization demand and delivery: Lessons from existing evidence at universities around the world, J-PAL conducts randomized evaluations to answer critical questions in the fight against poverty. We build partnerships with governments, NGOs, donors, and others to share this knowledge, catalyze adoption of evidence at scale, and advance evidence-informed decision-making. J-PAL was launched at the Massachusetts Institute of Technology in 2003 and has regional centers in Africa, Europe, Latin America and the Caribbean, the Middle East and North Africa, North America, South Asia, and Southeast Asia.