VoICE Immunization Evidence: Conflict and Humanitarian emergencies
Conflict and humanitarian emergencies
Sustaining immunization activities and preventing vaccine-preventable outbreaks during conflict can be achieved through preemptive preparedness measures and concerted programmatic and financial support from governments and partners.
During the conflict in Yemen, efforts spearheaded by WHO, with coordination among partners and effective use of resources, especially GAVI, resulted in continued high pentavalent vaccine coverage decreasing only 3% from 2010 to 2015. Yemen also remained polio-free through 2015 and smoothly introduced two new vaccines (MR and IPV).
During the humanitarian crisis in the Syrian Arab Republic, the constant support from WHO, UNICEF, and local NGOs resulted in immunizations against VPDs reaching over 90% of children.
Immunizing populations during complex humanitarian emergencies can help protect populations who are especially vulnerable to malnutrition and its effects.
Malnutrition is a leading contributor to morbidity and mortality during humanitarian emergencies, and a cyclical relationship exists between malnutrition and infectious diseases. Universal immunization programs have been shown to improve the height and weight measurement markers associated with malnutrition.
Children living in humanitarian crisis settings can be protected from the disproportionately high burden of vaccine-preventable diseases.
A two-dose schedule of rotavirus vaccine was estimated to be cost-effective in Somalia, where more than 20 years of civil conflict have significantly damaged the health system and vaccine coverage is exceedingly low. Researchers estimate that in 2012, routine use of rotavirus vaccine, even at low coverage rates, would have averted nearly 25% of deaths due to rotavirus diarrhea in Somali children under one year of age.
Children under 5 years of age bear the greatest burden of indirect conflict-associated mortality. (Indirect mortality is due to disruption of health services including immunization, food insecurity and high risk living conditions such as those found in refugee camps.) The leading causes of child death in these circumstances include respiratory infections, diarrhea, measles, malaria, and malnutrition.
Respiratory infections and diarrhea are the leading causes of death during humanitarian emergencies according to a 2016 review of vaccine-preventable diseases and the use of immunizations during complex humanitarian emergencies.
Vaccines are a cost-effective means to reduce the high burden of pneumonia and diarrhea suffered by children living in humanitarian crisis settings.
In a study modeling the cost-effectiveness of vaccination campaigns in Somalia – the country with the second largest number of refugees in 2012 – the use of Hib vaccine, PCV10, or both Hib and PCV10 were all found to be cost effective means to prevent excess morbidity and mortality from pneumonia in young Somali children. Such a vaccination campaign could conservatively reduce pneumonia cases and deaths by nearly 20%.
Children living in the Yida refugee camp in South Sudan in 2013 were found to have an elevated rate of pneumonia infections likely due to malnutrition, overcrowding, and inadequate shelter. Using these data, the CDC estimated that the use of Hib and pneumococcal vaccines in children under 2 years of age in the camp would be cost-effective under all dosing scenarios evaluated. Medecines Sans Frontiers (MSF) provided medical services to this refugee camp and found delivery of these vaccines to be feasible and effective in this setting.
Conflict and migration can lead to outbreaks, including in previously controlled or eliminated diseases, and jeopardized disease control efforts.
The ongoing conflict in Syria has caused the breakdown of immunization services, leading to outbreaks of vaccine preventable diseases in the region and the re-emergence of polio in Syria for the first time in 15 years. The potential for polio to re-emerge in neighboring areas with low coverage of inactivated polio vaccine (IPV) threatens the success of global efforts to eradicate polio.
Researchers investigating the causes of a measles outbreak in Burkina Faso that occurred despite a recent mass vaccination campaign found that migration to and from Cote d’Ivoire was a major risk factor for children. Unvaccinated children who developed measles were 8.5x more likely to have recently traveled to Cote d’Ivoire than unvaccinated children who had not traveled across the border. Children returning to Burkina Faso after a period of time in Cote d’Ivoire were less likely to have been vaccinated due to low routine coverage of measles vaccines in Cote d’Ivoire. Conversely, unvaccinated children from Burkina Faso who traveled to Cote d’Ivoire and returned were more likely to be exposed to measles and thus had a higher rate of disease than children who never visited Cote d’Ivoire.
Large measles outbreaks occurred in Lebanon and Jordan, following an influx of Syrian refuges migrating to escape conflict. In Lebanon, the measles incidence increased 200-fold in one year following high migration. There were 2.1 measles cases per million population in Lebanon in 2012; this increased to 411 cases in 2013.