Routine measles vaccination coverage in Bangladesh has declined since 2020, widening immunity gaps that experts say have played a critical role in the ongoing measles outbreak.

As of Tuesday, at least 273 children have died from suspected or confirmed measles cases, while nearly 40,000 infections have been reported across the country since March 15.

According to the Coverage Evaluation Survey 2023 funded by the government and different international agencies, the coverage of the first dose of the measles-rubella vaccine (MR1) dropped to 86 per cent in 2023 from 88.6 per cent in 2019.

The decline was sharper for the second dose (MR2), falling from 89 per cent in 2019 to 80.7 per cent in 2023, which has raised concerns over incomplete immunisation.

Public health experts said that the decline had prevented Bangladesh from achieving the ‘herd immunity threshold’ of about 95 per cent, necessary for interrupting measles transmission and meeting elimination targets.

Bangladesh had aimed to eliminate measles by 2020, but the target was later extended to 2026 after repeated failures to maintain adequate vaccination coverage.

According to a report by the United Nations Children’s Fund, about 10 million children for MR1 and 20 million children for MR2 remain susceptible to measles infection in the country.

The Directorate General of Health Services at a press conference at its office in the capital Dhaka on Wednesday said that 74 per cent of the infected children were unvaccinated, 14 per cent received only one dose while 12 per cent received two doses or fully vaccinated.

Bangladesh administers the first dose of the vaccine at nine months and the second dose at 15 months of age.

‘This widening immunity gap, accumulated over the past few years, has contributed to the recent surge in measles cases,’ UNICEF said in the report published on April 7.

The Coverage Evaluation Survey, conducted jointly funded by the government and international agencies, including UNICEF and the World Health Organisation, has long been used to monitor immunisation performance in the country.

The World Health Organisation said that the recent decline in immunisation coverage was driven by multiple factors, including a nationwide stock-out of measles-rubella vaccines between 2024 and 2025, disruptions in routine services and the absence of nationwide supplementary vaccination campaigns since 2020.

‘These gaps have increased the number of susceptible children and contributed to the current outbreak,’ the WHO said in a report published on April 23.

Bangladesh had made a steady progress in immunisation over the decades, increasing the coverage from just 2 per cent in 1985 to 83.9 per cent in 2019.

The COVID-19 pandemic disrupted routine vaccination services, said Mohammad Mushtuq Husain, a former adviser to the Institute of Epidemiology, Disease Control and Research.

He said that both vaccine supply and service delivery were affected after the pandemic due to funding constraints.

Bangladesh conducts routine immunisation alongside nationwide measles-rubella campaigns every four years in line with WHO recommendations.

The last campaign was held in March 2020, while a planned campaign in 2024 was not implemented due to a funding shortage.

Sector people said that the crisis deepened as the government shifted away from the operational plan-based funding mechanism under the Health, Population and Nutrition Sector Programme.

Although the programme’s fourth phase (2017–2022) formally ended in June 2024, funding constraints had already begun in 2022, further weakening immunisation services.

The vaccine shortage has persisted in 2026, with delayed policy decisions exacerbating the situation, sector people said.

Public health expert Professor Abu Jamil Faisel said that Bangladesh had failed to achieve the required immunity level, leaving a large unvaccinated population over the years.

‘The vaccination gap has been there for years, but it was not adequately addressed,’ he said.

Bangladesh introduced the measles-rubella vaccine in 2012 and achieved measles control status in 2018, later adopting an elimination action plan targeting 2020.

However, the deadline was first extended to 2025 and later to 2026 as the country failed to sustain the required immunisation coverage.