UHC Blog Series

Immunizations in complex humanitarian emergencies

By Sabere Traore

January 15, 2020

Disasters, both natural and man-made, are occurring globally with increasing regularity The International Disaster Database estimates that from the early twentieth-century to date, the world has experienced more than twenty-two thousand mass disasters. Another study observed that from 2006-2015, there were almost 1,680 floods, 249 earthquakes, 335 epidemiological outbreaks, 179 landslides, 160 droughts and 19 humanitarian emergencies due to conflict. Low- and middle-income countries (LMICs) are extremely vulnerable to disasters due to the lack of resources, weak political/governance structure, under-developed health infrastructure, and poor health and nutritional status within populations.


disasters as humanitarian crises:

Epidemics are both the cause and consequence of disasters. The Ebola outbreak in West Africa impacted a considerable size of the population and evolved into a humanitarian crisis. Similarly, in the post-disaster scenario, outbreaks of infectious diseases like cholera, malaria, measles, and pneumonia occur frequently in over-crowded camp settings leading to a high mortality rate. Between 1979-1997, these diseases accounted for 50-95% of the reported deaths in the refugee population in the early phases of emergencies in countries like Thailand, Malawi, Sudan and Congo


development of immunization framework in complex humanitarian emergencies (CHes):

Immunization in CHEs dates back to the 1970s, when measles immunization was adopted into the initial protocols. Despite this, measles remained among the leading causes of deaths in CHEs until 1990. However, two significant strategies helped decrease measles-related mortality. These strategies included expanding the target-age group and reducing the dose schedule which simplified campaign logistics and extended vaccine supply’s capacity. The success of the measles immunization campaign has been a milestone in not only tackling disease outbreaks, but also providing valuable lessons. First, immunization programs are as important as any primary health interventions in preventing VPDs. Secondly, implementing immunizations campaigns during CHEs significantly reduces overall mortality. Finally, expanding target-age groups and decreasing dose schedules can be effective in mitigating the disease threat and related deaths.

Although large-scale immunization campaigns significantly reduced the threat of measles, the burden of disease in CHEs has largely shifted to other VPDs. Diarrheal diseases and acute respiratory infections have emerged as the leading cause of mortality. Such recurrent outbreaks, across the globe, stimulated the World Health Organization (WHO) and nongovernmental organizations (NGOs) to acknowledge the severity of the problem and find a solution.

An initial challenge in running immunization programs during disasters was the lack of uniformed guidelines. The Pan American Health Organization’s Immunization program and Sphere standards were considered by the relief organizations for managing vaccination programs, but additional standardization was required. 

As a result, WHO's Strategic Advisory Group of Experts (SAGE) on Immunization designed a framework for immunization during CHEs. The purpose was to help governments and other decision-makers in the deployment and effective use of life-saving vaccines during emergencies, allowing countries to assess the epidemiological risk-factors presented by infectious diseases. This tool also emphasized that immunization should be a mandatory component of basic early interventions irrespective of the nature of CHEs. 

Disasters often cause disruption in routine immunization. Budgetary constraints, logistics issues, security situations and focus on more emergent issues in the disaster-affected population also pose challenges in accessing vaccines, leading to an increase in the risk and probability of outbreaks of vaccine-preventable diseases (VPDs). For example, in the aftermath of the 2010 earthquake in Haiti, a massive cholera outbreak erupted with more than 665,000 cases and over 8,000 deaths. Before this, Haiti had not experienced cholera outbreaks for more than a century

The current context of COVID-19 worsens the occurrence of VPDs as many countries have interrupted their immunization programs.


unique challenges to large-scale immunization during ches:

The goals and methods of vaccination during humanitarian crises are usually different from those during routine immunization. While the goal of routine immunization is to enhance the immunity of the population as a whole for long-term protection against various diseases; the primary objective of immunization in emergencies is to target high-risk epidemiological diseases and reduce mortality through mass immunization.

In the case of CHEs, there are additional challenges that require coordinated efforts to ensure efficient immunization response. For example, during emergencies, previous records of the target population may not be available which makes non-selective mass vaccination a preferred method for effective coverage. Additionally, unlike routine immunization that deals with a relatively stable population, a post-disaster setting is more unstable which makes immunization challenging. Logistical challenges such as inaccessibility due to damage in road network, disruptions in communication, difficulty in storage and maintenance of the cold chain due to infrastructure damage can also increase tremendously. Particularly, the financial condition of the host government after a disaster is extremely fragile. Since many organizations are involved in the relief and rehabilitation efforts, each with its particular mission, it becomes challenging to collaborate resources for vulnerable populations. 

Ethical issues are also worth noting during CHEs, especially in LMICs with inadequate healthcare infrastructure. These countries are dependent upon international agencies for prompt response during outbreaks. Such situations make it necessary to consider immunization against infectious disease outbreaks as part of the initial emergency response, along with food and refuge. Of course, several factors need to be considered before deploying a specific immunization campaign including; disease burden, vaccine related risks, suitability of disease prevention as opposed to treatment, intended duration of protection, logistical feasibility of launching large-scale immunization programs, total financial expenditure, and herd-immunity besides individual protection. 

Combatting chewith universal health coverage (uhc) :

Undoubtedly, CHEs pose a public health threat to the global community. The response efforts to these emergencies have improved significantly over the decades due to advancements in immunization campaign strategies which has collectively resulted in a gradual decrease in morbidity and mortality. However, there remain challenges in preventing and effectively managing the outbreaks of VPDs. Crafting a globally accepted decision-framework document, overcoming logistical challenges, further improving the disease surveillance system, collaborating with the stakeholders and addressing the ethical challenges in mass vaccination can improve the efficiency of the intervention during the outbreak of VPDs. We must ask ourselves what the contribution of UHC would be in ensuring that CHE affected populations have access to healthcare including immunization programs, and we must consider COVID-19 before deploying any interventions