Warning signs: How policy gaps fuelled the measles outbreak

Bangladesh is once again witnessing a troubling resurgence of measles – a disease it had nearly brought under control. In recent months, reported cases have risen sharply, accompanied by a worrying increase in child mortality. This upsurge is not an isolated event, but part of a broader global pattern observed in the post-pandemic period.

Yet, the speed and scale of transmission in Bangladesh reveal deeper systemic vulnerabilities. Measles, one of the most contagious human viruses, spreads rapidly in populations where immunity gaps exist; even a small decline in vaccination coverage can trigger explosive outbreaks. 

Epidemiological evidence consistently shows that at least 95% two-dose coverage is required to prevent transmission, a threshold that has not been consistently maintained in many settings in recent years.

Globally, the years following the Covid-19 pandemic have seen a significant backsliding in routine immunisation. According to the World Health Organization and Unicef, millions of children missed routine vaccinations during 2020-2022 due to service disruptions, lockdowns and health system reallocation. 

As a result, measles cases surged worldwide in 2024 and 2025, affecting both low- and high-income countries.

According to WHO  and Unicef, the global immunisation coverage for the first dose of measles-containing vaccine fell from 86% in 2019 to around 81% in 2021, leaving an estimated 25 million children un- or under-vaccinated.

This created a large pool of susceptible individuals, allowing the virus to re-emerge once mobility resumed. In that sense, Bangladesh's current outbreak is part of a predictable global rebound.

However, global explanations alone are insufficient. The resurgence in Bangladesh reflects a confluence of country-specific institutional, operational and behavioural challenges. 

One critical issue has been delays in procuring vaccines and essential supplies, including syringes and cold-chain equipment. Even short-term disruptions in supply chains can interrupt routine immunisation schedules, particularly in a system that relies heavily on continuous outreach.

Some anecdotal evidence and reports suggest that administrative bottlenecks and financing constraints contributed to such delays, weakening the Expanded Programme on Immunization (EPI) at a crucial moment.

A significant contributing factor to this systemic breakdown was the decision by the erstwhile interim government to withdraw and overhaul existing operational plans (OPs) under the Health, Population and Nutrition Sector Program. 

While the intent was to address corruption and historical irregularities, the timing and manner of this restructuring created a "transitional gap" that paralysed routine activities. By dismantling the established operational framework without an immediate, functional replacement, the government inadvertently disrupted the flow of funds and procurement approvals necessary for the EPI.

This set a damaging precedent where administrative reform took precedence over the continuity of life-saving services, leading to an alleged depletion of central vaccine stocks, including BCG and MR vaccines, by late 2024 and early 2025.

Equally important has been the disruption of routine vaccination activities due to interruptions in operational planning. Bangladesh's immunisation success historically depended on precise microplanning and regular outreach sessions. 

However, recent disruptions, linked to administrative changes and broader governance challenges, have affected the continuity of these services. In some areas, planned outreach sessions were postponed or cancelled, leading to missed cohorts of children. Over time, these missed children accumulate into what global health experts term "immunity gaps," which measles exploits with remarkable efficiency.

The health workforce crisis has further compounded the problem. Strikes by health assistants and a persistent shortage of frontline workers have significantly reduced the system's ability to conduct door-to-door vaccination and follow-up. 

Bangladesh's immunisation model has long relied on these grassroots workers, whose absence creates immediate service delivery gaps. In many regions, vacant posts have remained unfilled for extended periods, weakening routine immunisation coverage and surveillance capacity.

Another critical factor is the accumulation of so-called "zero-dose" children – those who have not received any routine vaccines. This phenomenon has been widely documented by Unicef as a major driver of measles outbreaks globally. In Bangladesh, the Covid-19 pandemic created a cohort of children who either missed their first dose or failed to complete the vaccination schedule.

Even after the pandemic, many of these children were not reached through catch-up campaigns, resulting in a growing pool of susceptible individuals. This is particularly concerning because measles transmission requires only a small cluster of unvaccinated individuals to ignite an outbreak.

Urbanisation has introduced additional complexity. While national immunisation coverage in Bangladesh appears relatively high on average, it masks significant subnational disparities. 

Urban slums, peri-urban settlements and hard-to-reach areas often have much lower coverage due to high population mobility, informal housing and weak service outreach. 

Studies by the World Health Organization have repeatedly highlighted that such pockets of low coverage can sustain transmission even when national averages are strong. In Dhaka and other major cities, these pockets have become increasingly important in explaining recent outbreaks.

Behavioural factors also play a role. Although Bangladesh has historically had low levels of vaccine hesitancy compared to many countries, there is emerging evidence of localised resistance linked to misinformation, religious conservatism, and distrust of public services. 

Even small increases in hesitancy can have disproportionate effects in high-density settings, where herd immunity thresholds must be strictly maintained. The spread of misinformation during and after the Covid-19 pandemic has likely contributed to this trend.

Addressing the current crisis requires urgent action, but also a shift in how immunisation systems are managed. 

In the immediate term, Bangladesh must prioritise large-scale catch-up vaccination campaigns targeting children who missed routine doses, particularly those under five years of age. This should be accompanied by rapid micro-targeting of high-risk areas, strengthened surveillance, and emergency measures to stabilise vaccine supply chains. Communication campaigns are equally critical to rebuild public trust and counter misinformation.

In the medium term, the focus must shift to rebuilding the integrity of the routine immunisation system. This includes filling vacant health assistant positions, restoring regular outreach services, and strengthening microplanning at the local level. Urban immunisation strategies need to be redesigned to account for mobility and informal settlements. Digital tracking systems could play a crucial role in identifying missed children and ensuring follow-up.

Over the longer term, Bangladesh must aim to sustain at least 95% two-dose measles vaccination coverage across all districts, not just on average but within every community. This requires resilient financing, efficient procurement systems, and integration of immunisation with broader primary health care services. Behavioural interventions, grounded in social science, will be essential to address emerging hesitancy and maintain public trust.

Ultimately, the resurgence of measles in Bangladesh is not simply a failure of vaccination; it is a reflection of broader systemic fragility. The country's past success in immunisation demonstrates that high coverage is achievable even in resource-constrained settings. But it also underscores a crucial lesson: such success must be continuously maintained.

Measles does not forgive complacency. Without sustained commitment, even the most preventable diseases will return, often with devastating consequences.

The author is director, Institute of Health Economics, University of Dhaka.

Disclaimer: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinions and views of The Business Standard.