Measles is one of the most contagious diseases in the world. A single infected person can pass it on to as many as 18 others in an unprotected population. It spreads through the air, moves fast, and hits young children hardest. In severe cases it leads to pneumonia, brain damage, and death.

The good news is that measles is entirely preventable. A safe and effective vaccine has existed for decades. When enough people in a community are vaccinated, the virus runs out of hosts and outbreaks stop. That threshold, known as herd immunity, requires at least 95 percent of the population to be protected.

The Philippines has not always reached that mark.

The Ligtas Tigdas Campaign

On January 19, 2026, the Department of Health launched Ligtas Tigdas, a Measles-Rubella Supplemental Immunization Activity targeting children aged six to 59 months across Mindanao. Vaccines were delivered through barangay health stations, schools, and outreach sites, with barangay health workers, local government units, and partner organizations working together to reach as many children as possible, including those in geographically isolated communities.

When the campaign ended, administrative reports placed vaccination coverage at approximately 80 percent. That figure falls short of the 95 percent target. And in some areas, coverage was even lower.

But how reliable is that 80 percent figure? Administrative data depends on population estimates that can be thrown off by population movement, rapid urbanization, and incomplete household records. The real coverage rate could be higher. Or lower. Without an independent survey, it is difficult to know.

APMARGIN Commissioned to Find Out

To get accurate answers, the DOH and the United States Centers for Disease Control and Prevention Philippines commissioned APMARGIN as the implementing partner for a Post-Campaign Coverage Survey, with technical assistance from IMA World Health Philippines. The survey will conduct face-to-face household interviews across 30 municipalities and 300 barangays in six Mindanao regions, reaching approximately 3,000 children. It will produce independent, evidence-based estimates of actual vaccination coverage, identify which children were not reached and why, and provide a regional picture of routine immunization performance.

Before field teams could be deployed, they needed to be trained.

Three Days in Davao City

From April 16 to 18, 2026, APMARGIN brought together 30 enumerators and supervisors at the Grand Menseng Hotel in Davao City for an intensive three-day training. Participants were drawn from five Mindanao regions: Region IX, Region X, Region XI, Region XII, and Caraga. They were selected from more than 100 applicants.

The training team was led by Dr. Agnes Pacho, Project Leader, with Dr. Nicolas Catindig as IT Consultant, Ms. Leslie Escalada and Ms. Aleja Jorge as consultants, Ms. Carmina Balbin as Project Associate, and Ms. Arlene Tapang as Finance Officer. Representatives from CDC Philippines and IMA World Health were also present throughout the training.

Day 1 covered the purpose and objectives of the survey, the field protocol, household selection procedures, and administrative requirements. Dr. Chung-won Lee, Immunization Program Director of CDC, delivered a welcome message emphasizing the urgency of the survey and the importance of neutrality and professionalism during data collection.

Day 2 opened with a virtual presentation by Mr. Francis Torreblanca of the DOH National Immunization Program on immunization services in the Philippines, covering herd immunity, the routine vaccination schedule, and how to interpret vaccination records. Participants then went through the survey questionnaire in detail before receiving hands-on training on KoBoToolbox, the Android-based digital platform they will use to collect data in the field. Each participant was provided a tablet and walked through the system step by step.

Day 3 put everything into practice. Teams were dispatched to assigned barangays across Davao City for a pilot field test, accompanied by APMARGIN and IMA World Health staff monitors. They returned by noon and spent the afternoon presenting what they observed, discussing challenges, and finalizing their regional work plans.

What the Pilot Test Showed

The pilot test was designed to surface real-world problems before they become obstacles in the field. It did exactly that.

Several barangays had household lists that were outdated, incomplete, or not organized by purok, complicating the random household selection process. Some teams encountered no eligible respondents at their first assigned households, reinforcing the importance of callbacks. Questions arose around cultural sensitivity in Muslim communities, how to handle households with multiple entry points, and what to do when GPS signals are unavailable.

Each issue was discussed, resolved, and documented so that all five regional teams go into actual data collection with the same protocols and the same answers.

What Happens Next

Following a final virtual run-through on April 24, 2026, field teams will begin actual data collection on April 27 and continue through May 16, covering 300 barangays across six regions. Data management runs from May 18 to 23, followed by analysis and report writing through June 15. The draft report is due June 19, with a results presentation on June 24 and the final report submitted on June 29, 2026.

The PCCS MR-SIA 2026 is being conducted under ethics clearance from the DOH Single Joint Research Ethics Board.

References

• Asia Pacific Management and Research Group, Inc. (2026). Training report: Training for enumerators and supervisors on Post Campaign Coverage Survey (PCCS), Measles-Rubella Supplemental Immunization Activity (MR-SIA) 2026 in Mindanao. APMARGIN.
• Single Joint Research Ethics Board, Department of Health. (2026). Notice of initial approval: PCCS MR-SIA 2026 [SJREB-2026-14]. DOH-SJREB.
• Department of Health, Republic of the Philippines and US Centers for Disease Control and Prevention Philippines. (2026). Post-campaign coverage survey protocol: MR-SIA Mindanao 2026. DOH-NIP and CDC Philippines.
• World Health Organization. (2023). Measles: Key facts. WHO.