Debarati Guha-Sapir, Maria Moitinho de Almeida, Sarah Elisabeth Scales, Bilal Ahmed, Imran Mirza
MEASLES: A WELL-STUDIED DISEASE, YET A LONG WAY TO GO
The fragile capacity of health systems to respond to measles in humanitarian settings is likely to break down completely, should the current COVID-19 pandemic ravage these populations.1 Conflict-driven humanitarian settings (hereafter humanitarian settings), characterised by armed conflict, insecurity, and mass displacements, are particularly vulnerable to the detriments of competing epidemics where a low capacity to carry out basic health system functions, such as vaccination programmes, facilitates the occurrence of disease outbreaks.2 Supply chains become sporadic, cold chains lose viability, beneficiaries avoid unsafe trips to health centres, and human resources are dissipated, creating ever-larger pools of unvaccinated children and jeopardising herd immunity. Delays in case detection due to disrupted healthcare or lack of laboratory capacity, exacerbated by the dynamic nature of conflicts, lead to late epidemic response and control. With over 135 million people living in areas of conflict,3 epidemics in humanitarian settings are a pressing global health concern: 14 million out of the 20 million (70%) unvaccinated children in 2018 are zero dose children, and an estimated 5.6 million are in conflictaffected settings.
Measles is a highly contagious and potentially deadly disease that can spread among malnourished and vitamin A deficient populations in humanitarian settings.4 Globally, measles cases have appreciably increased in the last years, especially in conflict-affected countries (table 1 and box 1). For example, the Democratic Republic of Congo is estimated to have had nearly 350 000 suspected cases of measles and over 6500 fatalities between January 2019 and March 2020.1
Measles must not become collateral damage to our efforts to contain COVID-19, and the urgent need for vaccination must be addressed despite the pandemic. Measles virus pathology and related medical technologies are well established and understood by the public health and scientific communities. The persistence of cases and increasing outbreaks in humanitarian settings is in part due to underutilisation of this knowledge. In addition to logistics and vaccine dose availability in health facilities—often the main preoccupation in humanitarian settings— weaknesses in vaccination planning within the health system are overlooked in the haste. For instance, as COVID-19 continues to spread globally, nearly 180 million children may miss out on receiving measles-containing vaccine (MCV). Measles immunisation campaigns in 29 countries have already been delayed; more will be postponed.5 Interruption of immunisation services poses a major risk for secondary outbreaks of vaccine preventable diseases leading to a measles epidemic in few months time that will kill more children than COVID19. As the pandemic lingers, the WHO is now urging countries to carefully resume vaccination while contending with SARS-CoV-2.
We find that fixing holes in health systems in these contexts may be equally important as lapses in vaccine coverage or availability and, indeed, may have more sustainable and lasting effects. We identify four parameters that could enhance health system resilience and optimise the effectiveness of measles prevention and control in humanitarian settings.