Testing a Biometric Identification System to Improve Malaria Vaccine Completion

A program that implements a digital vaccination record system linked to biometrics in health facilities, coupled with voice message reminders for caregivers of children who are due for or missed vaccinations. Simprints will provide tablets and train Community Health Workers (CHWs) to use facial biometric identification for children above 6 months old. It will also automatically identify children who missed a scheduled dose, enabling CHWs to follow up with caregivers to bring the child in or to help CHWs in their micro-targeting efforts. Finally, Simprints will automatically send caregivers' voice message appointment reminders to those caregivers of children who are due for or missed vaccination.

2025-10-25

2027-12-31

1. Completion of full malaria sequence (Index children)
2. Timely full malaria vaccination (Index children)
3. Completion of full routine vaccination sequence (basic antigens) (Index children)
4. Completion of full routine vaccination sequence (national schedule) (Index children)

1. Record of 4 doses of malaria vaccines for the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available) - measured at endline
2. Record of 4 doses of malaria vaccines for the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available) taken within the appropriate time frame:
Malaria dose 1: 24 to < 28 weeks
Malaria dose 2: 28 to < 32 weeks
Malaria dose 3: 36 to < 42 weeks
Malaria dose 4: 74 to < 82 weeks
Measured at endline
3. Records of doses of routine vaccines (basic antigens) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available). Defined as receipt of all of the following:
One dose of BCG vaccine
Three doses of polio vaccine given as oral polio vaccine (OPV),
Inactivated polio vaccine (IPV)
Three doses of Pentavalent vaccine (Penta)
One dose of measles-rubella vaccine (MR)
Measured at endline
4. Records of doses of routine vaccines (national schedule) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available).
Full vaccination coverage based on the national schedule is defined as the index child having received all the following:
BCG
Three doses of Pentavalent (Penta)
Four doses of OPV (including OPV given at birth),
One dose of IPV
One dose of yellow fever vaccine,
Three doses of pneumococcal vaccine (PCV),
Three doses of rotavirus vaccine,
Two doses of measles-rubella vaccine (MR).
One dose of meningitis A vaccine (MenA)
Measured at endline

1. Timely full routine vaccination sequence (basic antigens) (Index children)
2. Timely full routine vaccination sequence (national schedule) (Index children)
3. Early, Late or Very Late malaria vaccination (Index children)
4. Early, Late or Very Late full routine vaccination sequence (basic antigens) (Index children)
5. Early, Late or Very Late full routine vaccination sequence (national schedule) (Index children)
6. Number of malaria vaccines taken (Index children)
7. Number of routine vaccines taken (basic antigens) (Index children)
8. Number of routine vaccines taken (full national schedule) (Index children)
9. Number of timely malaria vaccines taken (Index children)
10. Number of timely routine vaccines taken (basic antigens) (Index children)
11. Number of timely routine vaccines taken (full national schedule) (Index children)
12. Received each vaccine on time (full national schedule) (Index child), analyzed individually
13. Up to date on malaria vaccine (children under 3 years old in study households)
14. Up to date on routine vaccines (basic antigens) (Children under 3 years old in study households)
15. Up to date on routine vaccines (full schedule) (Children under 3 years old in study households)
16. Cumulative number of late days in receipt of malaria vaccination (index children)
17. Cumulative number of late days in receipt of basic antigens (index children)
18. Cumulative number of late days in receipt of routine vaccines according to national schedule (index children)
19. Mother knows when to bring the child to the clinic for the first vaccination
20. Facility vaccine data accuracy

All secondary outcomes are measured at endline
1. Records of doses of routine vaccines (basic antigens) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available). Taken within the appropriate time frame:
One dose of BCG vaccine: At birth (0 days)
Three doses of polio vaccine given as oral polio vaccine (OPV):
OPV1: 5 to <7 weeks
OPV2: 9 to <11 weeks
OPV3: 13 to < 15 weeks
Inactivated polio vaccine (IPV): 13 to < 15 weeks
Three doses of Pentavalent vaccine (Penta):
Penta1: 5 to <7 weeks
Penta2: 9 to <11 weeks
Penta3: 13 to < 15 weeks
One dose of measles-rubella vaccine (MR): 36 to < 42 weeks
Records of doses of routine vaccines (national schedule) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available).
2. Full vaccination coverage based on the national schedule is defined as the index child having received all the following, taken within the appropriate time frame:
BCG: At birth (0 days)
Three doses of Pentavalent (Penta):
Penta1: 5 to <7 weeks
Penta2: 9 to <11 weeks
Penta3: 13 to < 15 weeks
Four doses of OPV:
OPV0: At birth (0 days)
OPV1: 5 to <7 weeks
OPV2: 9 to <11 weeks
OPV3: 13 to < 15 weeks
One dose of IPV: 13 to < 15 weeks
One dose of yellow fever vaccine: 36 to < 42 weeks
Three doses of pneumococcal vaccine (PCV):
PCV1: 5 to <7 weeks
PCV2: 9 to <11 weeks
PCV3: 13 to < 15 weeks
Three doses of rotavirus vaccine:
Rota1: 5 to <7 weeks
Rota2: 9 to <11 weeks
Rota3: 13 to < 15 weeks
Two doses of measles-rubella vaccine (MR):
MR1: 36 to < 42 weeks
MR2: 74 to < 82 weeks
One dose of meningitis A vaccine (MenA): 74 to < 82 weeks
4. Record of 4 doses of malaria vaccines for the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available). Taken outside the appropriate time frame.
5. Records of doses of routine vaccines (basic antigens) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available). Taken outside the appropriate time frame.
6. Records of doses of routine vaccines (national schedule) for the index child recorded in the individual child's booklet (or self-reported by the mother if the booklet is not available). Taken outside the appropriate time frame.
7. Number of recorded malaria vaccines taken (from 0 to 4) by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available)
8. Number of recorded basic antigens taken (0 to 9) by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available)
9. Number of recorded vaccinations taken (0 to 19) from the national schedule by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available)
10. Number of recorded malaria vaccines taken (from 0 to 4) within the appropriate time frame by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available)
11. Number of recorded basic antigens taken (0 to 9) within the appropriate time frame by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available)
12. Number of recorded vaccinations taken (0 to 19) from the national schedule within the appropriate time frame by the index child recorded by the individual child's booklet (or self-reported by the mother if the booklet is not available).
13. Among each of the following, analyzed individually, index child received the vaccine within the appropriate time frame according to the national schedule (as recorded in the individual child’s booklet or as self-reported by the mother)
BCG: At birth (0 days)
Three doses of Pentavalent (Penta):
Penta1: 5 to <7 weeks
Penta2: 9 to <11 weeks
Penta3: 13 to < 15 weeks
Four doses of OPV:
OPV0: At birth (0 days)
OPV1: 5 to <7 weeks
OPV2: 9 to <11 weeks
OPV3: 13 to < 15 weeks
One dose of IPV: 13 to < 15 weeks
One dose of yellow fever vaccine: 36 to < 42 weeks
Three doses of pneumococcal vaccine (PCV):
PCV1: 5 to <7 weeks
PCV2: 9 to <11 weeks
PCV3: 13 to < 15 weeks
Three doses of rotavirus vaccine:
Rota1: 5 to <7 weeks
Rota2: 9 to <11 weeks
Rota3: 13 to < 15 weeks
Two doses of measles-rubella vaccine (MR):
MR1: 36 to < 42 weeks
MR2: 74 to < 82 weeks
One dose of meningitis A vaccine (MenA): 74 to < 82 weeks
14. Record of having taken all doses of malaria vaccine as appropriate for child’s age as recorded by the children’s booklets (or self-reported by the mother if the booklet is not available)
15. Record of having taken all doses of basic antigens as appropriate for child’s age as recorded by the children' s booklets (or self-reported by the mother if the booklet is not available)
16. Record of having taken all doses of national vaccine schedule as appropriate for child’s age as recorded by the children' s booklets (or self-reported by the mother if the booklet is not available)
17. Among those who received at least a dose of the malaria vaccine, the number of days late the vaccine(s) were relative to what the national schedule considers “on time” for each dose. Late days are equal to zero for those who received the vaccine on time or early.
18. Among those who received at least one dose of basic antigens, the number of days late the vaccine(s) were relative to what the national schedule considers “on time” for each dose. Late days are equal to zero for those who received the vaccine on time or early.
19. Among those who received at least one dose of routine vaccines according to the national schedule, the number of days late the vaccine(s) were relative to what the national schedule considers “on time” for each dose. Late days are equal to zero for those who received the vaccine on time or early.
20. Mother self-reports being sure or very sure about when to bring the child to the clinic for the first vaccination
21. Discrepancy in the total number of children vaccinated based on paper-based records at the facility vs digital records in DHMIS. Measured as the vaccine “verification factor” for BCG, Penta 3 and MR-2 over a three month period, comparing the total number of children vaccinated with each of the three vaccines over this period reported in DHIMS 2 with the paper-based record.

This research study aims to generate rigorous evidence on how digital identification systems (face biometrics) may increase malaria and other routine vaccine completion rates for young children in Ghana.

We will implement a cluster-Randomized Controlled Trial (c-RCT) in the Oti region, considering a cluster of the catchment areas of close-by health facilities. We will select a sub-sample of about 100 clusters: half of the clusters will receive the intervention (treatment group), and half will serve as a control group. All facilities within the cluster will be assigned to either treatment or control group.

In the treatment group, Simprints will provide tablets and train Community Health Workers (CHWs) to use biometric identification for children above 6 months old. It will also identify children who missed a scheduled dose enabling CHWs to follow up with caregivers to bring the child or to help CHWs in their microtargeting efforts (i.e., bringing vaccinations to the communities). Finally, Simprints will automatically send caregivers' voice message appointment reminders on a schedule to be determined during initial field testing.

In the control group, CHWs will keep operating as before. About 30 health facilities in Jakisan district are expected to be using the GHS e-tracker. In the e-tracker facilities, CHWs will continue their usual work practice in regard to digitally recording patient details and services received, which may vary in levels of fidelity and frequency. In all facilities, regardless of whether the e-tracker is being used, paper records are maintained. This includes the CHW updating the vaccine tally register, and the aggregate numbers are reported into the Digital Health Information Management System (DHIMS) monthly.

Stratification - We will stratify based on three geographical regions (groups of districts), and a proxy for volume of patients (above or below the median of total number of caregivers visiting health facilities in March, April, May 2025, bringing children for vaccinations). We will have in total 6 strata. We are excluding two districts in Northern Ghana, because of feasibility and budget constraints (Nkwanta North and Nkwanta South).

Not available

Stratified randomization of facilities was conducted using the Stata (v.18) “randomize” command. Two variables were used for stratification. One was an indicator for the geographical region of the facility (3 total regions), and the other was an indicator for whether the facility was above or below the median in the distribution of the total number of caregivers bringing their child to the facility for vaccination in March, April, and May 2025. The randomization (among 2000 replications) that achieved the best balance based on the total number of caregivers bringing their child to the facility for vaccination in March, April and May 2025, and the total number of malaria cases in March, April, May 2025 was selected.

The catchment area of health facilities is defined as a group of health facilities grouped by geographical proximity. Health facilities include health centers and CHPS compounds.

Yes

About 100 catchment areas, totaling about 120 health facilities

We expect on average 41 women in their last two trimesters of pregnancy or women with children under 6 months old in the catchment area of a health facility. We plan to enroll both pregnant women (in the last two trimesters) as well as women with children under 6 months in the communities around each health facility. We expect to enroll about 4100 (pregnant in the last two trimesters or with children under 6 months old) women in about 100 health facility catchment areas.

41 women X 50 clusters = 2,050 women in treatment
41 women X 50 clusters = 2,050 women in control

From the 2021 Census conducted in Ghana, in the Oti region there have been 21,788 births in the last 12 months (21,090 surviving children), that is 1,757 children each month. If we enroll all pregnant women in their last two trimesters, we expect to enroll 10,542 each month. We plan to follow up the newborns as well as women with children under 6 months. This would give us a sample of children up to 30 months, by the time of endline data collection (24 months after baseline). Given the total number of health facilities in the Oti region (256), we conservatively estimated a cluster size of 41 pregnant women per health facility cluster. A first primary outcome of interest is the proportion of index children completing the full malaria vaccine sequence (aged 18 to 30 months at the time of endline). Assuming an average of 46% in the control group (MoH Ghana, 2022), a power level of 80%, an alpha of 5%, and an ICC 0.1 based on work by Levine et al. 2021, we estimate that we need 49 clusters per treatment arm to estimate a minimum detectable effect of 10 percentage points. Simprints’ baseline conducted in Oti in August 2024 confirmed a rate between 62.7% and 55.1% from the first dose to the last (fourth) dose of the malaria vaccines, requiring 47-49 clusters. A second primary outcome of interest is the proportion of index children who complete the full routine vaccination schedule (aged 18 to 30 months at the time of endline). Assuming an average of 73% in the control group (DHS, 2022), we assume that our intervention increases completion of routine vaccination by 10 percentage points. We estimate we need 34 clusters per treatment arm. Simprints’ baseline conducted in Oti in August 2024 confirmed a rate of 22.7% for all antigens, 85.3% for basic antigens, and 62.1% for all vaccines in the national schedule. Up to 48 clusters will allow us to estimate a minimum detectable effect of 10 percentage points in all these outcomes. We propose a sample size of about 100 clusters of close-by health facilities, randomly allocating 50 each for treatment and control. We expect to enroll 4100 pregnant women, plus 15% to account for attrition.