How reliable services and incentives increased immunization rates by six-fold

Intervention · 


Every year, more than 25 million pregnant women and children lack access to basic immunization programs, with an estimated two to three million deaths resulting from diseases preventable through vaccination.1 This intervention examined the change in immunization rates in response to a reliable supply of immunization services and incentives. The experimenters assigned villages into three groups: Group A villages were provided with monthly immunization camps; Group B villages were provided with similar camps but also small incentives in the form of raw lentils and metal plates; control group villages had to consult their government healthcare facilities for immunization. The results were very interesting; villages within Group B that were provided incentives had a 21% higher full-immunization record than the villages in Group A. Moreover, villages receiving a reliable supply of services within Group A and B had significantly higher immunization rates compared to the control group.


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Rating = 5/5 (Direct benefits to participants, effective, significant results)

How reliable services and incentives increased immunization rates in rural India
Control group 6% of the children were fully immunized
Reliable monthly immunization camp 18% of the children were fully immunized
Reliable monthly immunization camp and incentives (raw lentils and metal plates) 39% of the children were fully immunized

Key Concepts

Incentivization: The practice of rewarding a certain behavior with a positive outcome. This reward often works to reinforce the behavior and increase future recurrence. 

Positive Reinforcement: Strengthening the likelihood of a future behavior through adding a positive consequence after the behavior is carried out.

The Problem

Low immunization rates across communities

There are many vaccines that are administered shortly after birth to ensure healthy development and prevention of diseases. The CDC recommends 6 vaccinations to be administered within the first two months of birth.2 While people may take such vaccinations for granted, many countries including India have low immunization rates among children, making them susceptible to a range of serious diseases. By age 2, only 44% of children in India have received the basic immunization requirements. This number drops to 22% within large rural areas, while surrounding disadvantaged populations, such as those involved in this study, have immunization rates lower than 2%. 

Inaccessibility to reliable healthcare 

The public healthcare system within many rural areas is highly unreliable, including the villages involved in this intervention. Since a complete immunization course requires a minimum of five visits to a healthcare facility, it’s hard for children to complete the course with an unreliable and inconsistent presence of doctors in the area. This intervention studied the effect of reliable health services on the immunization rates by regularly setting up immunization camps every month. Additionally, social workers reached out to families to educate them on the benefits of immunization and directed them to the established camps. 


Selection of Villages and Samples

A total of 134 villages were randomly selected by a computer program within the bounds of the Seva Mandir catchment area in the city of Udaipur, India. Of the total, 60 villages were a part of the treatment groups and 74 villages were in the control. Each of the treatment groups, Group A and Group B, included 30 villages each. The effect of the interventions on neighboring villages was also studied by providing immunization services to people visiting from nearby villages that are not a part of the sample. Villages from each group were more than 20 km away from the other groups, sufficiently minimizing any spillover and maintaining an independent sample. 

A household census was conducted in each village, and 30 households with children aged 0-5 years were chosen at random to be a part of the sample. Another survey was conducted at the end point of the study for the households in the sample. The criteria for a child to be included in the study to be aged 1-3 years by the end point survey. The final sample included 2188 children, 2898 households, and 134 villages. 

Distribution of Vaccines and Incentives

Both treatment groups established a regular availability of immunization services within each village, with a nurse and an assistant setting up a camp every month. The camp was held on a fixed date during specified hours. Children were provided with the WHO-UNICEF extended immunization package which included one BCG vaccine dose, three DPT vaccine doses, three oral polio vaccine doses, and one dose of the measles vaccine. 

Treatment Group B consisted of the same camp infrastructure but also provided additional incentives to families of the children immunized. The incentives were designed to be of immediate use and nutritional value, offering parents with 1 kg of raw lentils and a set of metal plates. The value of lentils and plates was estimated at 2 days worth of wages. The villages in the control group received no treatment and had to obtain immunization at the closest healthcare facility, as usual. 

The 4E Framework

The design of this intervention exemplifies the 4E Framework, a behavioral change framework that focuses on encouraging a particular behavior through providing increased services, incentives, and information. The 4E framework is widespread in it’s applications and the four components can slightly differ depending on the context. 

  • E(nable): Reliable and timely immunization camps were set up to provide services to the people of the village free of cost. The services were provided to any child under 5 years of age that approached the camp, even visitors from neighboring villages. 
  • E(ncourage): Social workers went across town spreading the information of the immunization camps and the importance of being fully immunized. Villagers in treatment Group B were provided with added incentives and encouragement in the form of raw lentils and plates if they participated. 
  • E(ngage): The community was engaged beyond the sample villages. Many families from neighboring villages visited the immunization camps because of both the reliable immunization services as well as the incentives. 
  • E(xemplify): The social workers educated parents of the importance of vaccination and referring them to the immunization camps. 

Results and Application

Reliable immunization services doubled immunization rates 

Both Group A and Group B were given treatments of reliable immunization camps, compared to the control group that had little to no reliable immunization facilities. The results show a significantly higher immunization rate within the treatment groups; Group A had twice the immunization rate and Group B had six-times the immunization rate compared to the control group. Although Group B had additional treatments, the doubled immunization rate in Group A is a fair comparison and strong indicator of the effect of reliable services on immunization rates.

Incentives increased uptake of immunization services

The results show a significantly higher immunization rate within the treatment group that received incentives compared to the groups that did not receive any incentives. Group B had the highest full immunization rates, with a mean of 39%, a 21% higher rate than Group A and 33% higher than the control group. 

Incentives also increased immunization retention rates; 67% of children that received one injection in the Group B camps were fully immunized by the end of the study, compared to Group A retaining 48% of children in completing the immunization course. Additionally, of the children that had one dose of injections prior to the camps, 52% completed the immunization course in Group B compared to 23% in Group A. 

Increased immunization rates in neighboring villages

The treatment groups attracted visitors from neighboring villages to also receive immunization. By the end of the study, 20% of children in villages a few kilometers away from Group B camps were fully immunized, and 11% of children in neighboring villages close to Group A had completed the immunization course. It should be noted that the immunization rates were as low as 2% in most villages prior to the intervention. The incentives associated with immunizations on-top of the reliable services significantly increased immunization rates in all nearby villages. 

Retail & Consumer Retail companies often use incentives to attract and retain consumers. Incentives can be in the form of a “Buy one, get one free” deal or free shipping when purchasing $100 worth of items. 
Education Incentives have been found to be effective in improving concrete concepts such as beginner-intermediate level math, but show little effectiveness in conceptual courses, like the sciences.
Health & Wellbeing In the short-term, incentives can be a good method to increase motivation to engage in healthy behaviors. If these behaviors become persistent, they can snowball into long-term habits, assuming a person has adequate intrinsic motivation as well.



Does the intervention demonstrably improve the lives of those affected by it?
Hundreds of children received free complete immunizations that offer protection from many common and serious diseases
Does the intervention respect the privacy (including the privacy of identity) of those it affects?
The experimenters did not disclose any personal or private information of the participants
Does the intervention have a plan to monitor the safety, effectiveness, and validity of the intervention?
The experimenters made sure to confirm which children had previously received injections and standardized measures were taken for safe immunizations

Does the intervention abide by a reasonable degree of consent?
The villagers had the option to opt out of immunizations, regardless of the social workers’ educating efforts
Does the intervention respect the ability of those it affects to make their own decisions?
The parents and children were not forced to participate in the immunization camps, and were given a complete choice
Does the intervention increase the number of choices available to those it affects?
Not Applicable
Parents had a better opportunity of immunizing their children, in turn, also providing them with more of a choice over if they want to immunize their children or not

Does the intervention acknowledge the perspectives, interests, and preferences of everyone it affects, including traditionally marginalized groups?
The lack of education on the topic is acknowledged by the experimenters and attempted to be bridged by the social workers educating parents within the village on the importance of immunization
Are the participants diverse?
Room for improvement
The participants all belong to a low socio-economic status within the rural areas of Udaipur, India
Does the intervention help ensure a just, equitable distribution of welfare?
The immunization camps allow more children to live a healthier life, indirectly providing more opportunities for economic advancement

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A Behavioral Approach to COVID-19 Vaccine Hesitancy

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  1. Banerjee, A. V., Duflo, E., Glennerster, R. (2010). Improving immunisation coverage in rural India: clustered randomised controlled evaluation of immunisation campaigns with and without incentives. BMJ (Online), 355, i6423–i6423.  
  2. Centers for Disease Control and Prevention. (2020, February 25). What vaccines will my baby get? Centers for Disease Control and Prevention.,Hib 
  3. Bettinger, E. (2012). Paying to learn: The effect of financial incentives on elementary school test scores. The Review of Economics and Statistics, 94(3), 686-698.
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