Disease X Redux

A new BBC documentary meets the scientists working to identify the next pandemic pathogen. But the best defence lies in bolstering health capacities in the world's emerging disease hotspots.

“Humanity has three great enemies: fever, famine and war. Of these, by far the greatest, by far the most terrible, is fever.”– Sir William Osler

On Monday, the BBC screened a curious documentary, Disease X: Hunting the Next Pandemic. Presented by Chris Van Tulleken, an associate professor at University College London, the film sees Van Tulleken travel from London to Geneva, Malysia and California in pursuit of pathogens that could spark the next pandemic.

I write “curious” because “Disease X” is the World Health Organization’s term for a pathogen with pandemic potential that is presently unknown to science – in epistemological terms, an “unknown unknown”. Examples from the last half century of pandemics include the Human Immunodeficiency Virus (HIV) Severe Acute Respiratory Syndrome (SARS) and SARS CoV-2, the virus of Covid-19.

But as any epistemologist will tell you, the problem is that if a pathogen is presently unknown to science then it’s impossible for scientists to predict if it poses a threat ahead of time. As the former US Secretary of Defense Donald Rumsfeld once put it, there are things we simply “don’t know we don’t know”.

However, that is not a reason to stop looking and the film does a good job of bringing viewers up to speed on the pathogens that scientists already know about which keep that up at night. These include the bird flu virus H5N1, which I’ve written about in previous posts, and Nipah virus, which first appeared in 1998 in Malaysia sparking cases of acute encephalitis and respiratory illnesses in pig farmers and abattoir workers. Van Tulleken also briefly covers MERS (Middle East Respiratory Syndrome) and the filoviruses, Ebola and Marburg. Quoting the Canadian pathologist William Osler, Van Tulleken reminds us that, along with famine and war, fever is humanity’s greatest enemy.

However, what is missing is any discussion of whether we are any better prepared for the next pandemic than we were five years ago and the role that science plays in misdirecting and preparing us for the wrong pandemics.

In my book The Pandemic Century I argued that the lesson of previous 20^th and 21^st century pandemics was that the tendency of researchers to focus on known pandemic pathogens locked scientists into self-limiting paradigms and theories, blinding them to the pandemic just around the corner. The result was that, rather than thinking outside the box and pursuing lines of research viewed by their peers as career dead-ends, scientists exhibited a herding instinct that made them prone to groupthink.

This was seen most clearly in the initial phase of Covid-19 when, modelling their response on influenza, the World Health Organization (WHO) insisted that SARS CoV-2 was a droplet infection, rather than an aerosol, and was unlikely to be conveyed from person to person over long distances.

It also helps explains why the United States and Britain –­ according to the Global Health Security Index two of the supposedly best-prepared countries for a pandemic – fared so poorly in their responses to SARS-CoV-2, failing to roll out test-and-trace and recommend public masking at a time when it could have made a difference to the spread of the virus.

Since then, of course, we have gone backwards. In the United States, the Trump administration has slashed the budget of the National Institutes of Health, cancelling $2 billion in research grants, including funding for Covid-19 research and mRNA vaccines that could hold the key to our response to Disease X.

Meanwhile, the UK Vaccine Taskforce, which succeeded in developing and procuring Covid-19 vaccines in record time, was disbanded in the autumn of 2022. And although the British government is investing billions in a new biosecurity centre in Harlow, Essex that promises to be Europe’s largest hub for pathogen research, there is no reason to believe that the endemic problems identified by the taskforce’s former head, Kate Bingham – namely, Whitehall’s poor scientific skillset, aversion to risk and its “culture of groupthink” – have gone away.

But perhaps the biggest lesson from past epidemic emergencies is that the best defence against Disease X is to send multidisciplinary scientific teams to known disease hotspots in search of the next pandemic virus before it can hit our shores. Since 1940, scientists have identified 335 new human infectious diseases. Nearly two thirds are of animal origin. Of these, 70 percent originated in wildlife, with bats harbouring a higher proportion than any other mammal.

A good example is Uganda, which has seen several outbreaks of Marburg and Ebola in areas where fruit bats that harbour filoviruses like to roost. Thanks to modern, hand-held genetic sequencing devices, the ability to identify these viruses is much easier than in the past. Indeed, towards the end of the film Van Tulleken visits Glasgow’s Centre for Virus Research to see these devices for himself, explaining how, armed with a virus’s genetic code, scientists can use AI to construct its proteins and devise medical countermeasures.

“I feel there’s room for optimism,” Van Tulleken enthuses. “The science they are doing here makes us safer.”

However, one of the key factors in preventing the wider spread of Ebola in 2014-2016 when the virus sparked a regional epidemic in West Africa, was that Nigeria possessed strong core health capacities thanks to funding from the President’s Emergency Plan for AIDS Relief (PEPFAR) and the Global Fund to Fight AIDS, Tuberculosis and Malaria. Those programmes ensured that when a Liberian businessman infected with Ebola arrived in Lagos – a city with a population of 1.4 million and a gateway to several international destinations – Nigeria was able to mobilise teams of contact tracers and prevent community spread of Ebola and its introduction to countries outside Africa.

However, because of the evisceration of the United States Agency for International Development’s humanitarian aid programmes under Elon Musk and Trump’s withdrawal of funding to PEPFAR, that local clinical expertise is being lost, meaning that when the next pandemic virus emerges there will likely be no one on the ground to signal the alarm. And as Van Tulleken points out, Trump’s decision to withdraw from the WHO has only heightened that risk.

Perhaps the most salient part of the film comes when Van Tulleken visits the WHO’s Emergency Operations Centre in Geneva and sits in on a meeting of its Public Health Intelligence Unit. Here, analysts from around the globe collate outbreaks that might “signal” the emergence of Disease X and issue reports to member states. On the day Van Tulleken visited, these included a case of avian influenza in Vietnam, yellow fever in the Americas, haemorrhagic fever in Iraq and anthrax in Uganda.

Fortunately, these are all viruses we have known about for some time. The worry is that tomorrow they could mutate in new and unexpected ways and no one will notice.