The continuing deaths show the initial relief campaign was inadequate, public health expert Dr Mushtuq Hussain told the BBC.
He said it left too many children unprotected and should have covered more regions and age groups.
“When it comes to answering, there are no shortcuts,” he said. “The government made the right decision to take action. But health workers needed to go door to door to convey the message of urgency to people.”
The WHO insists the campaign was a success, but admits that “some targeted children were not reached.”
“The outbreak spread throughout the country before vaccination efforts took place, creating extensive chains of transmission that will take time to completely interrupt,” the WHO said in a statement to the BBC.
The majority of cases occur in unvaccinated children, with about 83% of confirmed measles cases occurring in those who have not been vaccinated and 10% in infants under six months of age, who are therefore “highly vulnerable during outbreaks,” according to the WHO.
Malnutrition makes people especially vulnerable and increases their likelihood of developing serious complications or dying from measles.
Bangladesh is also particularly vulnerable during an outbreak, as child malnutrition can increase the risk of serious complications and death from measles.
Hospitals have been overwhelmed by the outbreak.
When the BBC visited some of them in June, dozens of families were seen lying on blankets on the floor, and one hospital said its capacity had more than doubled.
At the time, the health minister acknowledged the strain on the health system but said that was to be expected given the country’s population of more than 170 million and that the government had “already dealt with the problem” and the number of cases was falling.
Since then, another 300 children have died.
Globally, Bangladesh is not the only country to have an outbreak this year, although not all are of this severity.
The UK was thought to have eradicated the disease, but lost that status this year.
The United States has also seen a rise in measles cases in recent years, and children under five in both countries have fallen short of the 95% vaccination threshold needed for herd immunity.
Additional reporting by Sardar Roni
