These results only include cohorts 1-8, 11 (see more detailed coverage report here). Additional survey data will be added at a future date.

What Are Coverage Surveys?

New Incentives collects extensive data to monitor our program as we scale up to reach millions of infants.

Vaccination coverage surveys—also called rapid assessments—are a key component of our monitoring strategy. The surveys take place every six to 12 months to measure the proportion of children in a given geographic area who are vaccinated, along with other related indicators. The findings complement the positive findings we have from the randomized controlled trial of our program to enable us to keep a constant pulse on our program's impact and cost-effectiveness throughout our scale-up.

How Do Coverage Surveys Work?

We first conduct coverage surveys before expanding the program in a new local government area (LGA). We then conduct follow-up surveys approximately six months after operations begin and continue to monitor coverage every six months. New Incentives groups the LGAs it expands to within a given state at a given point in time into cohorts. Households are surveyed on self-reported vaccine coverage, perceptions of vaccines, barriers to vaccination, receipt of incentives, and other household characteristics.

How Do We Use Coverage Survey Data?

Coverage surveys allow us to answer two key questions:

1. Do vaccination coverage levels at follow-up surveys (at least 12 months post-baseline) suggest that New Incentives is achieving a level of success within a cohort that justifies the cost of operations there?

2. Are there specific cohorts that could benefit from greater outreach?

We can then use these results to increase awareness efforts, engage stakeholders in developing and implementing solutions for identified gaps, or shift our strategy to target areas that have lower vaccination coverage.

Findings of Coverage Surveys

In 2021, New Incentives engaged IDinsight to design a measurement strategy to collect rigorous and accurate data with which to assess coverage levels over time. New Incentives later engaged IDinsight to analyze data from the baseline and 24-month follow-ups for cohorts 1-8 and 11. The findings shared here are based on IDinsight’s analysis.

There were 3,734 baseline surveys and 4,102 third follow-ups analyzed for these cohorts.

Change in Vaccination Coverage over Time

The chart below shows the change in vaccination coverage over a two-year period for BCG, Penta 1, and Measles 1. The initial baseline survey was conducted before program rollout and the most recent follow-up survey took place approximately 24 months later. 

BCG coverage increased by 22 percentage points, Penta 1 by 25 percentage points, and Measles 1 by 18 percentage points.

The chart below shows the change in vaccination coverage observed in the coverage surveys as compared to the randomized control trial as well as GiveWell’s estimates at the 24-month follow-up.

“We have set these guesses to be consistent with the coverage increases found in the New Incentives RCT, but expect coverage increases to be lower at earlier follow-up rounds because the New Incentives program won't yet be fully phased in.” - GiveWell

It’s important to note the limitations of these surveys and how they can be used in conjunction with the results from the RCT.

“The vaccine coverage assessments will not have a control group, as the randomized controlled trial (RCT) on which our top charity recommendation for New Incentives is based did, so they constitute lower-quality evidence of impact. We expect to use the newer data in conjunction with the results from the RCT to estimate New Incentives' impact as it expands to new locations and as time passes since the RCT was conducted.” - GiveWell

Change in Vaccination Coverage among Zero-Dose Children

Gavi, WHO, and other global immunization partners are committed to reducing the number of “zero-dose children,” which is defined as a child who has not received any doses of diphtheria-, tetanus-, and pertussis-containing vaccines. In Nigeria’s Routine Immunization Schedule, these are included in the Penta vaccine.

The percentage of zero-dose children decreased by a total of 25 percentage points at the 24-month follow-up.

Change in Vaccination Coverage by Sex

Sex-specific differences in coverage between baseline and 24-month follow-up were also analyzed. Caregiver-reported coverage of each routine childhood immunization included in coverage monitoring was slightly higher among female children than male children at baseline.

At the 24-month follow-up, the baseline trend is reversed completely and now male children have higher coverage rates than female children for all incentivized vaccines.

This data is useful as we seek to understand any gaps between female and male children, bringing vaccine equity to all infants in our operating areas. Equipped with this data, we can tailor awareness activities to ensure that all children have equal uptake regardless of their sex and that no groups are being left behind.

Caregiver Perceptions of Vaccines

When asked about the reason for missing one or more vaccines, a fairly high percentage fell into the “Other” or “Don’t know” category. Spouses or family members who are hesitant remain an enduring obstacle to overcome. 

It is also noteworthy that respondents less frequently report the reason for missing the vaccine to be due to vaccine stockout. This proportion decreases from about 9% at baseline to less than 1% at the 24-month follow-up suggesting that vaccine availability might have increased over time. 

Caregivers who reported their children received at least one vaccine were asked why they chose to vaccinate their children. The most common answer was “to prevent disease or illness,” with the percentage staying roughly the same, suggesting that the knowledge of the benefits of vaccination after 24 months did not change very much.

The incentive was cited by no more than four respondents at baseline and both follow-ups, indicating that the incentive was not the main motivating factor. This could suggest that the incentive is not influencing people’s choices, but could also suggest that change that is driven by the incentive enables caregivers to act on the positive motivations that already exist. 

Future Updates

We are continuing to conduct follow-up surveys in areas where we are currently operating. We will continue to do so to measure the impact of the program on immunization coverage over time and will update this page as additional data is published.