The World Health Organization (WHO), in collaboration with the Government of Bangladesh (GoB), has launched a two-round ‘mop-up’ campaign using the bivalent Oral Polio Vaccine (bOPV) to vaccinate 144,317 children under five years of age in the Rohingya Refugee Camps in Cox’s Bazar. This initiative is part of the WHO Global Polio Surveillance Action Plan 2022-2024.
Poliomyelitis (Polio) is a highly infectious viral disease primarily affecting children under five years of age. The virus spreads mainly through the faecal-oral route or, less frequently, via contaminated water or food. It multiplies in the intestine and can invade the nervous system, causing paralysis.
“As a proud polio-free nation, Bangladesh remains unwavering in its vigilance to uphold this status. This collaborative campaign exemplifies our steadfast dedication to protecting every child's health and ensuring a polio-free future, even in the most vulnerable communities,” says Dr Bardan Jung Rana, WHO Representative to Bangladesh.
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An infant receives the polio vaccine in Rohingya camps, September 2024
Photo Credit: WHO/ Terence Ngwabe Che
Since August 25, 2017, approximately 700,000 Rohingya people have fled to Cox’s Bazar, Bangladesh, due to violence in Rakhine State. As of March 2024, over 942,944 refugees reside in Cox’s Bazar, creating a densely populated environment with heightened health risks, including polio.
In 2014, Bangladesh was certified polio-free by the WHO South Asia regional certification committee, marking a significant public health milestone. However, in January 2024, environmental samples from Rohingya Refugee Camps 21 and 24 detected Sabin-like type 1 polioviruses (SL1) with a seven-nucleotide (7nt) change. This indicated sub-optimal coverage of three doses of bOPV through the routine Expanded Programme on Immunization (EPI), leading to an accumulation of susceptible individuals.
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WHO staff monitors the correct input of information for accountability, Rohingya camps, September 2024
Photo Credit: WHO/ Terence Ngwabe Che
The presence of SL1 in the environment suggests that the vaccine virus is circulating and potentially undergoing changes that could enable it to cause paralysis, thus becoming a vaccine-derived poliovirus. This poses a significant risk to the health of children in the Rohingya Camps.
To mitigate this risk, WHO and the GoB have launched a two-round ‘mop-up’ campaign using bOPV. This campaign, part of the WHO Global Polio Surveillance Action Plan 2022-2024, aims to vaccinate 144,317 children under five years of age in the Rohingya camps at Ukhiya and Teknaf, Cox’s Bazar, with two doses of bOPV.
“This campaign exemplifies our steadfast dedication to eradicating polio and safeguarding the health of every child, paving the way for a polio-free future in even the most vulnerable communities,” says Dr Jorge Martinez, Head of the WHO Sub office in Cox’s Bazar.
The two-round campaign was conducted as follows: the first from July 14-31 2024, and the second from September 1-12, 2024. A total of 1,650 Community Health Workers (CHWs) and 140 Community Health Supervisors (CHWS) conducted house-to-house visits across the 33 camps in Ukhiya and Teknaf to ensure high immunization coverage.
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Fig1: Camp-wise administrative coverage for rounds one and two of bOPV, July & September 2024.
The primary goal of this WHO-funded campaign, which includes vaccine procurement, implementation costs, and technical support, was to achieve high immunization coverage. This will protect the population from polio and reduce disease-related mortality and morbidity. By ensuring effective coverage, the campaign aimed to prevent the circulation of vaccine-derived poliovirus.
By the conclusion of the first round, 176,052 children (122% of the target) received the bOPV vaccine, exceeding our goal of 144,317. In the second round, the target was set at 176,052, and 175,482 children (99.7% of the target) received their second dose. Also, during the second round, 7,497 children received their first dose, including 1,957 newly arrived children (Fig. 2).
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Fig 2: bOPV coverage for rounds one and two, July & September 2024
This vaccination campaign was a critical step in safeguarding the health of Rohingya children and underscores the global commitment to immunization and continuous efforts to reach every child, especially in vulnerable communities. For more information about this publication, please contact Terence Ngwabe Che, External Communications Officer, Cox’s Bazar Sub Office at chet@who.int