The government will launch a nationwide serological study to determine whether children have developed adequate immunity after receiving the measles-rubella (MR) vaccine, as Bangladesh continues to battle a widespread measles outbreak.
Officials said the study will begin after the required immunoassay analyzer—currently being imported from abroad—arrives in the country.
According to government data, 118 children died from measles and measles-like symptoms in July following the launch of the special MR vaccination campaign. During the same period, 30,209 children were hospitalized, while nearly 1,000 new cases are being detected on average every day.
According to the Directorate General of Health Services (DGHS), the special vaccination campaign began on April 5 in 30 upazilas and municipalities across 18 high-risk districts after the outbreak started in March. It was expanded to the two Dhaka city corporations, Barisal, and Mymensingh on April 8 before being rolled out nationwide on April 20.
Health Minister Sardar Md Sakhawat Hossain said the country's measles situation has yet to come fully under control, adding that most current patients are either unvaccinated or suffering from malnutrition.
He also acknowledged discrepancies in the campaign's target population, saying the estimates provided by the World Health Organization (WHO) had left nearly 4.6 million children outside the vaccination drive.
The government had initially targeted 18 million children aged six to 59 months for the special MR campaign and reported achieving 103% coverage. By comparison, the National Vitamin A Campaign targeted 22.6 million children in the same age group, leaving a gap of about 4.6 million children between the two programs.
The minister said the government will review the estimates in a fresh meeting and plans to bring the excluded children under vaccination as quickly as possible.
Public health experts, however, cautioned that vaccination alone will not be enough to control the outbreak.
They said rapid case detection, isolation of infected children, stronger hospital preparedness, intensive surveillance in high-risk areas, and greater public awareness are equally important to curb community transmission.
According to the experts, coordinated public health interventions should have been implemented from the outset of the outbreak. Children with fever should be kept away from others, while hand hygiene, mask use where appropriate, and public awareness campaigns should be strengthened.
Antibody testing to measure immunity
Vaccine expert Tajul Islam Bari said antibody levels should be measured after vaccination to determine whether children have developed adequate protection.
He said an antibody level of at least 120 IU/ml is generally considered protective, while children with lower levels may require revaccination. Conducting serological surveys in outbreak-prone areas would provide a clearer picture of the vaccine's effectiveness and whether additional doses are necessary.
Explaining why some children become infected before reaching the eligible vaccination age, Bari said malnutrition, maternal malnutrition, vitamin A deficiency, underlying illnesses, and inadequate breastfeeding all increase the risk of severe infection.
Public health expert Dr Mushtuq Husain said post-marketing surveillance following vaccination campaigns is an internationally recognized practice that helps assess how many people have developed immunity and how effectively a campaign has performed in the field.
He said Bangladesh now needs to complement vaccination efforts with a broader public health strategy to contain the outbreak.
Study to begin after equipment arrives
Institute of Epidemiology, Disease Control and Research (IEDCR) acting director Dr Kazi Ahmed Zaki said the nationwide serological study would begin as soon as the imported immunoassay analyzer reaches Bangladesh.
"Since this equipment is not available in the country, it has to be imported. We expect it to arrive within this week. Once it does, we will begin the antibody-related research," he said.
The findings, he added, will show what proportion of children who received the MR vaccine have developed adequate immunity.