The rising number of measles infections and deaths in Bangladesh is raising concern among health experts, who say malnourished children are failing to develop sufficient antibodies despite vaccination efforts.
Even after the completion of a nationwide one-and-a-half-month special immunization campaign, officials and experts say the situation has not improved as expected. The government’s Expanded Program on Immunization (EPI) claims that more than the target—104% of children—were vaccinated during the campaign. However, infections and deaths continue to rise.
Experts say that after measles vaccination or natural infection, it usually takes one to three weeks for antibodies to develop in a child’s body. Accordingly, vaccinated children should already have developed protective immunity. However, in many cases antibody production is delayed or inadequate.
They attribute this to severe malnutrition, diarrhoea, protein deficiency and poor nutritional intake, which they say are preventing children from developing adequate immune responses, leaving them vulnerable to infection and death.
The government launched the special measles vaccination campaign in April amid rising outbreaks. The program began on April 5 in 30 high-risk upazilas across 18 districts. On April 12, it expanded to Dhaka North, Dhaka South, Mymensingh and Barisal city corporations. From April 20, the campaign was extended nationwide and to remaining city corporations. It concluded on May 20 as scheduled. During the period, more than 18.3 million children were vaccinated.
Medical experts say that despite the extended campaign, infection and mortality rates have not declined as expected, largely due to widespread child malnutrition. They say poor nutrition, inadequate protein intake and low breastfeeding rates are reducing vaccine effectiveness in many children or slowing antibody production.
Public health and vaccination expert Dr Tajul Islam A Bari said the first dose of the measles vaccine is administered at nine months of age and the second at 15 months. However, in developed countries, the first dose is typically given at 15 months and the second at four to six years of age, when children have lower malnutrition rates and more stable immunity.
He said vaccine effectiveness is closely linked to age and nutritional status. “The younger the child, the lower the effectiveness; it increases with age,” he said, adding that maternal immunity also plays a key role in early protection.
In Bangladesh, maternal antibodies generally protect children against measles up to around nine months of age, he said. For this reason, vaccination begins at nine months, as maternal protection gradually declines.
However, he noted that many children are now being infected before reaching nine months of age. As a result, vaccination is being administered from six to 59 months of age. He attributed this to declining exclusive breastfeeding rates and faster waning of placental immunity.
Dr Tajul Islam explained that children receive passive immunity from their mothers in two ways: through the placenta during pregnancy, known as IgG antibodies, and through exclusive breastfeeding after birth, known as IgA antibodies.
He said maternal antibodies can sometimes interfere with vaccine effectiveness, as IgG and IgA levels remain high in early infancy. “If vaccination is given before nine months, its effectiveness may be reduced,” he said.
He noted that vaccine effectiveness is around 50% at six months of age, about 85% at nine months, around 90% at 15 months, and up to 97% at pre-school age.
He added that IgM antibodies, which are produced within about seven days after vaccination, provide short-term protection, while IgG antibodies provide long-term immunity and take three to four weeks to develop.
“All antibodies are protein-based,” he said. “If a child is malnourished, has poor growth, lives in overcrowded conditions, or has low breastfeeding intake, antibody production is hindered.” This increases the risk of measles infection and complications such as diarrhea, pneumonia and encephalitis, which can lead to death.
He stressed that at least 95% of children in every district and upazila must receive both vaccine doses to achieve herd immunity. Routine immunization must also be strengthened, alongside periodic campaigns.
“Routine immunization is the backbone of the programme,” he said, adding that maintaining high coverage helps protect the remaining unvaccinated children through herd immunity.
He further emphasized improved nutrition and breastfeeding as essential preventive measures, saying there is no alternative.
Director of the Infectious Diseases Hospital Dr. F. A. Asma Khanom said children of unvaccinated mothers are not receiving adequate protection. She said women should receive vaccination before pregnancy to ensure maternal immunity is passed to the child.
“When mothers are vaccinated, children are born with maternal immunity,” she said, adding that vaccination at six and nine months further strengthens protection. She warned that children of unvaccinated mothers remain at higher risk of infection and death, particularly those with weakened immune systems.
Meanwhile, the Directorate General of Health Services (DGHS) said on Friday that 11 people died with confirmed measles or symptoms over the past 24 hours (Thursday morning to Friday 8:00 a.m.) across the country.
During the same period, 1,315 patients were admitted to hospitals.
From March 15 to May 22, suspected measles cases reached 60,540 nationwide, while confirmed cases stood at 8,329. Over the same period, 414 suspected measles deaths and 85 confirmed measles deaths were reported.
