Why Measles Campaigns in Africa Need Better Data, Targeting and Follow-Up

Africa's measles vaccination campaigns have saved lives on a historic scale, but a new 25-year review shows that the next phase of elimination will not be won by bigger campaigns alone. It will depend on finding the children who remain invisible to health systems, especially in districts where national success stories hide local gaps.

A study in Vaccines reviewing measles and measles–rubella campaigns across the WHO African Region from 2001 to 2025 shows a striking dual reality. On one hand, the Region has mounted one of the largest recurring public health operations in the world: 326 preventive campaigns across 44 countries, delivering more than 1.5 billion vaccine doses. On the other hand, the study finds persistent gaps in district-level coverage, weak post-campaign verification, and limited tracking of zero-dose children: the very children campaigns are meant to reach.

Campaign Machine Is Massive, But Measles Exploits Every Gap

The scale of Africa's vaccination effort is extraordinary. Most of the campaigns reviewed were nationwide exercises, and many were designed to reach all eligible children, regardless of whether they had been vaccinated before. These supplemental immunization activities have been central to the Region's measles-control strategy because routine immunization systems alone have not consistently reached enough children.

The study notes that measles elimination strategies are estimated to have averted 21 million deaths in the African Region between 2000 and 2024. First-dose measles vaccine coverage rose from 50% in 2000 to 71% in 2024. Rubella vaccine has also been introduced into routine immunization in many countries. But measles leaves little room for partial success. Because it is highly contagious, even small pockets of unvaccinated children can sustain outbreaks. This is why WHO guidance expects at least 95% coverage not only nationally, but in every district.

Nearly two-thirds of campaigns with administrative data met the 95% national coverage target, but district-level performance was far weaker. Of the campaigns that reported district-level data, only a small fraction achieved 95% coverage in every district. This is a critical lesson for policymakers: national averages can mislead.

When the Data Doesn't Add Up

Administrative campaign coverage often depends on reported doses delivered and estimated target populations. But those estimates can be wrong. Census data may be outdated, populations may shift, children outside the target age group may be vaccinated, and reporting systems may overcount doses. The paper found that one-third of campaigns reported administrative coverage above 100%, with some above 110%. That does not mean impossible success. It usually signals problems with denominators, reporting or targeting.

The more reliable check is a post-campaign coverage survey. Yet surveys were conducted after only 29% of campaigns. Among those surveyed campaigns, only 19% achieved coverage of 95% or higher. In many cases, survey results were substantially lower than administrative figures.

If countries overestimate coverage, they may delay corrective action until outbreaks reveal the truth. If districts with low immunity are hidden inside strong national reports, campaigns may continue to miss the same children year after year. And, if post-campaign surveys are not done quickly, health authorities lose the chance to close gaps before transmission resumes.

The next generation of measles campaigns must therefore treat data as a frontline intervention. Better maps, better denominators, better survey systems and faster feedback loops are as important as vaccine supply.

More Than Just Vaccines

The study also shows that measles campaigns have become more than vaccination drives. From 2006 to 2025, nearly two-thirds of reviewed campaigns included at least one additional health intervention. Vitamin A supplementation and deworming were the most common additions. Some campaigns also integrated polio vaccination, insecticide-treated bed nets, neglected tropical disease interventions, malaria prevention, nutritional screening and other health services. Ethiopia used some campaigns to screen for malnutrition, clubfoot and obstetric fistula. Nigeria integrated multiple interventions during its 2025 measles–rubella catch-up activities.

Campaigns can reach communities that routine health services often miss. In remote, underserved or fragile settings, an immunization campaign may be one of the few moments when health workers reach children at scale. Used well, campaigns can become platforms for broader child survival and health equity.

Still, integration should not be treated as an automatic win. Adding services increases complexity. It demands stronger planning, more supplies, more training, more supervision, better cold-chain management, and clearer communication with communities. If poorly designed, integrated campaigns can overload frontline workers and weaken the core objective: reaching every child with measles protection.

The policy challenge is to use campaigns intelligently, not as catch-all delivery vehicles, but as carefully planned opportunities to close multiple health gaps where operational capacity allows.

The Children Still Missing

The key purpose of supplemental measles campaigns is to reach children who did not receive routine vaccination. These zero-dose children are often found in remote settlements, conflict-affected areas, informal urban settlements, migrant communities, displaced populations or households with low trust in health services. The study found that the number of zero-dose children reached was documented in only 19 campaigns since 2018 - a major weakness. Without knowing whether campaigns are reaching the previously unreached, countries may simply be revaccinating easier-to-reach children while leaving the highest-risk groups behind.

Reaching zero-dose children requires more than vaccines. It requires community mapping, local trust-building, transport planning, social mobilization, security-sensitive delivery, better microplanning and stronger accountability at district level. The study points to lessons from polio eradication, including satellite mapping, GPS tracking of vaccinators, rapid campaign evaluation and targeted social mobilization. These tools could help measles programs move from broad campaigns to more precise operations.

However, countries also need political ownership, predictable financing, community engagement and stronger routine immunization systems. Campaigns can close gaps, but they cannot permanently compensate for weak everyday services.