A large measles outbreak of 1,700 cases occurred in the Rohingya refugee population in Cox’s Bazar, Bangladesh in 2017. In response, two reactive vaccination campaigns delivered the measles and rubella (MR) vaccine to children aged 6 months to 15 years old. This modeling study found that these reactive vaccination campaigns rapidly curbed outbreak transmission, averting an estimated 77,000 measles cases in the refugee camp. This demonstrates that reactive vaccination campaigns can be highly effective in preventing large measles outbreaks in the context of refugee camps, even when prior vaccination rates are low.
In Afghanistan, delivering health services through sustained, scheduled mobile health teams in remote and conflict-affected villages improved coverage of maternal and child health interventions, including immunization. The proportion of children under 1 year receiving their first dose of measles vaccine was higher in districts that had received mobile health team services for at least the previous 3 years (73.8%) compared to control districts in the same province (57.3%). The researchers concluded that incorporating mobile clinics into health system infrastructure in a systematic way can effectively improve health for hard to reach mothers and children in remote and conflict-affected areas.
This modeling study examined the impact of conflict events on disease control efforts during an Ebola outbreak in the Democratic Republic of the Congo. The model used a timeline of conflict events and an ethnographic appraisal of attacks on health care workers and treatment centers to estimate their impact on the epidemic trajectory of Ebola. Overall, the population-level effectiveness of vaccination was reduced by 43% due to disruptive conflict events. The researchers also found that declining incidence of Ebola was repeatedly reversed by conflict events. This framework can be extended to other diseases and regions experiencing conflict.
The results of a 2016 cross-sectional polio serosurvey found that the Jordan Ministry of Health’s proactive campaign to locate and vaccinate high-risk populations has been successful in maintaining high population immunity — even with a recent influx of refugees from Syria. The study included a community sample of 479 children under 5 years living in areas of Jordan identified as high risk due to being hard-to-reach, having high numbers of refugees, and lower vaccine coverage (under 90%). Polio immunity was found to be over 96% for polio types 1, 2, and 3 even for children living in refugee camps.
Forced migration due to the Syrian civil war has led to a re-emergence of several infectious diseases in Turkey, including vaccine-preventable diseases, such as measles (930 cases reported among refugees over 4 years), tuberculosis and hepatitis A.
In contrast to non-Somalis, family wealth did not significantly affect the likelihood of being fully vaccinated among Somali refugee children living in Kenya. This may point to systemic barriers to vaccination that cut across all socio-economic levels of the Somali refugee population.
The development and successful implementation of a coordinated, multi-country plan in response to a wild polio outbreak in Syria and Iraq halted the outbreak within 6 months. The response, which involved strengthening acute flaccid paralysis surveillance and more than 70 synchronized mass polio vaccination campaigns in 8 Middle Eastern countries (reaching >27 million children), could serve as a model for responding to disease outbreaks in areas affected by conflict and political instability.
An outbreak of wild polio virus began two years after the onset of the civil war in Syria and subsequently spread to Iraq, causing a total of 38 cases (36 in Syria). Factors leading to the outbreak included a decline in polio surveillance and in polio vaccination coverage (from 83% for 3 doses of oral polio vaccine pre-war in Syria to 47-52%).
The humanitarian emergency in Venezuela, and resulting collapse of its primary health care infrastructure, has caused measles and diphtheria to reemerge — disproportionately affecting indigenous populations — and spread to neighboring countries. This sets the stage for the potential reemergence of polio. The re-establishment of measles as an endemic disease in Venezuela (with >5,500 confirmed cases) and its spread to neighboring countries threaten the measles-free status.
Providing a birth dose of hepatitis B vaccine to all newborns (in addition to routine HepB immunization) was found to be a highly cost-effective means of preventing hepatitis B-related deaths in three refugee populations in Africa which are at extremely high risk of hepatitis B infection. Providing a birth dose only to newborns whose mothers test positive on a rapid diagnostic test was less cost-effective than vaccinating all newborns automatically. Thus, universal hepatitis B vaccination of newborns should remain a priority in refugee camps, despite competing humanitarian needs.