At the end of May, World Health Organization member states will convene their annual meeting in Geneva and elect a new director-general. This leadership transition at WHO unfolds at a defining moment, when shifting demographics are forging a new global public health landscape. Competing priorities — from non-communicable diseases to universal health coverage and polio eradication — will drive the agenda. But perhaps none is more suited to the health mandate of a community of nations as the existential threat of a pandemic. When the new director-general takes the helm on July 1, at the top of his or her list should be a focused and targeted approach to ending the pandemic era.
These widespread, sometimes global outbreaks of infectious disease didn’t appear overnight. Instead, the pandemic era has been forged out of centuries of humanity’s aggressive remodeling of the planet and its delicate balance of biodiversity. Viral pandemics — those for which our existing arsenal of vaccines and therapeutics are limited — originate almost exclusively from animals. Think influenza, Ebola, SARS, Zika, and, of course, HIV, which originated in primates.
We’re on pace to crowd 9.7 billion humans onto the planet by 2050, and 11 billion by the end of the century. This gives the viruses an advantage. Wildlife, humans, and the livestock we depend upon, pressed into ever greater contact, are opening up new vistas to viruses with global ambitions. And despite our individuality, immunologically humanity is a vast monoculture, rendering us a very suitable host.
On the eve of the centennial anniversary of the 1918 influenza pandemic, which killed approximately 50 million people around the world, we should remember that our fate is bound to pathogens and the disrupted environments from which they emerge.
By any account, the last 12 months have been a remarkable year for pandemic-capable viruses. An explosive global proliferation of avian influenza has prompted massive containment efforts spanning the United States, Europe, Africa and Asia. More than 35 million birds have been destroyed in South Korea alone. In China, over the last six months the H7N9 strain of avian influenza gained new footing, pushing past 500 human cases. That’s more than a third of all officially reported cases since the virus emerged in 2013. The trend was so alarming that representatives from WHO and the Food and Agriculture Organization in Beijing jointly issued a statement. “The acceptable number of human fatalities from avian influenza is zero,” they said. “And every new human case of H7N9 should remind us that there is an epidemic in the making.”
Meanwhile, in the Arabian Peninsula, the Middle East respiratory syndrome (MERS) coronavirus continued a pattern of sporadic spillovers, likely from camels into people, before flaring into larger outbreaks in hospital settings, where crowded wards of already weakened patients and sub-optimal infection control provide fertile ground for the birth of a pandemic. This MERS virus — closely related to the SARS virus that tore through global communities in 2003, leaving more than 8,000 cases in its wake — has previously demonstrated its proclivity for widespread transmission. In 2015, a single traveler-introduced infection in South Korea branched into 186 MERS infections in the largest hospital-potentiated outbreak of the disease reported to date.
Nipah, Lassa, Ebola, Crimean-Congo hemorrhagic fever, Zika — the list of offenders continues to expand.
Dynamic, rapidly evolving viral threats emerge with increasing frequency, exploiting new pathways in endless pursuit of their biologic imperative. These viruses are the paradigm of adaptive learning. Pushing and probing at our defenses, they shift to new hosts, opportunistically hijack transmission routes, and acquire capacities to evade immune detection. They are subject to no rules of engagement, and their viral intelligence is anything but artificial.
Can we put the genie back in the bottle? Probably not. In many cases, the viruses are widespread in their animal reservoirs, circulate silently, and challenge aggressive detection efforts required for an eradication strategy — a feat that has been achieved across the arc of human history only for smallpox and rinderpest. And the known threats are only a fraction of the seething cauldron of mammalian transmissible viruses on the planet, which new research supported in part by the US Agency for International Development suggests may number in the hundreds of thousands.
Can we, instead, modify our exposure risk? Can we reduce the likelihood of these yet-unknown viruses finding favorable conditions for emergence as the next pandemic? Absolutely.
To start, we must fill the substantial gaps that remain in our understanding of complicated dynamics of transmission risk. Essential questions remain unanswered. Why are human MERS cases from Saudi Arabia four times the total number of cases from all other countries? How can we explain the apparent lack of human MERS cases across North Africa, where the virus is active in the region’s camel population? Following an annual decreasing trend, what underpins the surge in H7N9 human cases this year? And after a repeated pattern of animal-borne influenza viruses that emerge in China and expand across the region, why has H7N9 appeared to stop at the country’s borders? We don’t know. These uncharted spaces at the boundaries of our understanding limit the ability to target resources and efforts where they are likely to have the greatest impact — for both known and as-yet unknown threats.
It’s tempting to think of these as academic inquiries. They are not. As the arrival of Ebola to Dallas and the introduction of Zika into Florida demonstrate, these pandemic-capable viruses are, at any given time, less than a day’s journey from appearing in emergency rooms across America.
We should move to end the pandemic era the same way that corporate titans tackle self-driving cars, interplanetary travel, and a renewables-based, carbon-neutral future. We need dedicated core groups populated with cross-sectoral expertise that are given a focused mandate and the task of identifying end-state goals. Then we must empower them with the resources, access, and support structures to catalyze alliances that will achieve these goals. They will fill these gaps in our understanding along the way, and generate new approaches that may solve other intractable global health problems.
We must also recognize that our sclerotic, siloed health systems no longer reflect the challenges we face today. Where possible, standalone surveillance architectures established for tracking a single pathogen must transition to versatile disease detection platforms that do more with less. Systems built to monitor seasonal influenza, for example, should also detect first incursions of other respiratory transmissible viruses, such as MERS and SARS-like coronaviruses.
Following the introduction of Ebola virus into Lagos, Nigeria, during the 2014 epidemic, the turn-on-a-dime repurposing of polio contact tracing and disease detection expertise built over years of foundational field epidemiology training averted a catastrophe. In a country of 182 million, the number of Ebola cases was held to 19. We need more of that foundational epidemiology training around the world. And the Nigeria experience should serve as a model for the nimble systems — and institutional and human resource reforms — required to meet our 21st century challenges.
Finally, we need to make an economic case for prevention and capitalize the transition to flexible, efficient human and animal health systems that can prevent disease transmission and, if necessary, rapidly detect and contain emergences of infectious diseases before they become pandemics. The historical record on this is clear: we either mobilize support now or we pay heavily later.
Globally, we have known the perils of inaction all too frequently — the tragic health consequences that permanently impact lives; the staggering economic costs; the incalculable social disruption. There is a better way forward, informed by the evidence and inspired by bold, creative approaches and a collective will to secure a world free from the ever-looming threat of pandemic disease. But we must act now.
As delegates arrive in Geneva this month for the World Health Assembly, we would do well to remember that the course of 21st-century events will depend in large measure on how we manage this formidable challenge. A failure to seize current opportunities and hasten the end of the pandemic era leaves our global community — and future generations — exquisitely vulnerable. That’s a legacy no generation should have to bear.
Daniel Schar, VMD, is the senior regional emerging infectious diseases advisor at the United States Agency for International Development’s regional mission in Bangkok. The views expressed here do not necessarily reflect those of USAID or the US government.