Measles Surge in East Asia and Pacific: A Wake-Up Call for Immunization

A alarming rise in measles cases across East Asia and the Pacific has prompted urgent warnings from global health authorities, with the World Health Organization (WHO) describing the trend as a “dangerous comeback” of vaccine-preventable diseases. Countries like the Philippines, Cambodia, Mongolia, and Vietnam are grappling with sharp increases in infections, signaling critical gaps in immunization coverage that leave millions of children vulnerable. As measles cases reach their highest levels since the onset of the Covid-19 pandemic in 2020, health officials are calling for immediate action to protect communities and prevent further outbreaks.

Rising Cases Highlight Systemic Failures

In the Philippines, the Department of Health (DOH) reported 2,068 measles cases and 50 rubella cases between January 1 and May 10, 2025, marking an 8 percent increase compared to the same period last year. The National Capital Region, encompassing Metro Manila, recorded the highest number of cases at 642, followed by other densely populated areas such as Calabarzon and Central Luzon. While the case fatality rate has slightly declined to 0.42 percent from 0.46 percent in 2024, the upward trend in infections underscores a broader regional challenge.

WHO data indicates that measles cases across the Western Pacific are at their peak since 2020, a stark reversal of progress made in prior years. In Vietnam, Cambodia, and Mongolia, similar spikes have been observed, often tied to disruptions in routine immunization programs during and after the Covid-19 crisis. “The alarming rise in measles cases is a wake-up call” said Dr. Saia Ma’u Piukala, WHO Regional Director for the Western Pacific. He emphasized that many of the affected children, particularly those in underserved communities, have not received even a single dose of the vaccine, highlighting inequities in healthcare access.

June Kunugi, UNICEF Regional Director for East Asia and the Pacific, echoed this concern, noting that the surge is not merely a spike in disease but a signal of faltering health systems. “Measles is highly infectious, and children are paying the price for gaps in coverage, delayed care, and misinformation” she said. “No child should suffer or die from a disease we know how to prevent.”

Progress and Setbacks in the Philippines

Amid the troubling regional trend, there are glimmers of success in specific areas. The Bangsamoro Autonomous Region in Muslim Mindanao (BARMM), which faced a severe measles outbreak in 2024, has seen a dramatic 90 percent reduction in cases, dropping from 1,179 to just 121 in the same period this year. This achievement follows a massive Measles Outbreak Response Immunization (MORI) campaign that vaccinated over 1.2 million individuals. Philippine Health Secretary Teodoro Herbosa credited the success to community cooperation, stating, “Last year, President Marcos told me to solve the measles outbreak in BARMM. With the strong cooperation of our Bangsamoro brothers and sisters, we vaccinated 1,203,497 individuals as part of MORI. This kind of vaccination effort is what we must do, on a routine basis.”

Yet, national immunization rates remain far below the threshold needed for herd immunity. According to DOH figures from February 2025, only 64.85 percent of the 2.4 million children under one year old—roughly 1.55 million—have been fully immunized. This falls short of the 95 percent target required to prevent disease transmission, even among unvaccinated populations. The shortfall leaves significant portions of the population at risk, particularly in urban slums and remote rural areas where healthcare access is limited.

Broader Regional Challenges

The resurgence of measles in East Asia and the Pacific reflects a confluence of factors, including pandemic-related disruptions, vaccine hesitancy fueled by misinformation, and strained health infrastructures. Routine immunization programs, which form the backbone of disease prevention, were sidelined during Covid-19 lockdowns as resources shifted to emergency responses. In Vietnam, for instance, health centers reported significant declines in vaccination rates during 2020 and 2021, a trend that has yet to fully recover. Cambodia and Mongolia face similar hurdles, with logistical challenges in reaching remote communities exacerbating the problem.

The highly contagious nature of measles—spread through respiratory droplets and capable of infecting up to 18 unvaccinated individuals per case—makes even small gaps in coverage devastating. A single outbreak can rapidly spiral into a public health crisis, particularly in densely populated urban centers like Manila or Hanoi. The disease can also lead to severe complications, including pneumonia and encephalitis, disproportionately affecting malnourished or immunocompromised children.

Government and Global Responses

In response to the crisis, the Philippine DOH has ramped up efforts to bolster its National Immunization Program, which provides free vaccines for 12 fatal diseases, including measles, rubella, polio, and tuberculosis. Recent initiatives include the “Bakuna BayaniJuan: Big Catch-up Immunization” campaign, launched in the National Capital Region from November to December 2024, which vaccinated nearly 1.75 million individuals. Additionally, a school-based immunization program reached 3.8 million students nationwide, targeting older children who may have missed early doses.

Health Secretary Herbosa has called for intensified efforts, drawing on past successes in containing other outbreaks. “Routine vaccination should be done faster, higher, stronger, and together” he said, citing the dramatic reduction in pertussis cases in 2025—down to 200 from nearly 3,000 in 2024—as evidence of the DOH’s capacity to act decisively when supported by political will and community engagement.

Globally, the WHO and UNICEF are urging governments to prioritize catch-up campaigns and address systemic barriers to vaccination. The timing of the current surge, coming just a month after World Immunization Week in April 2025, has added urgency to these calls. During the annual event, countries like the Philippines conducted large-scale vaccination drives targeting infants and young children, yet the persistent rise in cases suggests that such efforts must be sustained year-round to close coverage gaps.

Barriers to Herd Immunity

Achieving herd immunity, which requires vaccinating at least 95 percent of a population, remains a distant goal for many countries in the region. Beyond logistical challenges, vaccine hesitancy poses a significant obstacle. Misinformation, often spread through social media, has led some parents to delay or refuse vaccinations for their children, falsely believing that vaccines cause autism or other adverse effects—claims repeatedly debunked by scientific studies. In the Philippines, distrust in immunization programs spiked following the controversial rollout of the Dengvaxia vaccine in 2016, which was linked to adverse reactions in some children, though subsequent investigations clarified the risks were overstated.

Economic constraints also play a role. While vaccines under the DOH program are provided free of charge, indirect costs—such as travel to health centers or lost wages for parents taking time off work—can deter families from seeking care. In rural Vietnam and Cambodia, where healthcare facilities may be hours away, these barriers are even more pronounced. Addressing such inequities requires not only increased funding for mobile vaccination units but also targeted public awareness campaigns to rebuild trust in health systems.

The Path Forward

The measles surge in East Asia and the Pacific serves as a stark reminder of the fragility of public health gains. While countries like the Philippines have demonstrated the potential for rapid response—as seen in BARMM’s dramatic case reduction—the broader regional trend points to deep-rooted challenges that demand sustained investment and innovation. Strengthening routine immunization, combating misinformation, and ensuring equitable access to healthcare are critical steps to prevent future outbreaks of not just measles, but other preventable diseases like polio and pertussis.

As health authorities race to close vaccination gaps, the stakes could not be higher. With millions of children still unprotected, the region stands at a crossroads: act decisively now, or risk further reversals in the fight against diseases long thought to be under control. For communities across the Philippines, Vietnam, and beyond, the question remains whether this wake-up call will spur lasting change—or if the lessons of the past will once again be forgotten.