Scientists study notional Disease X to prepare for another pandemic
Four years ago, the novel coronavirus emerged in the central Chinese city of Wuhan.
Now scientists around the world are sharpening focus on an unknown threat referred to as “Disease X”.
The World Health Organisation first included X on its list of priorities five years ago.
The term covers the pathogens, identified or as yet unknown, that are said to pose the biggest threats, but for which there may not be adequate countermeasures.
“Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen unknown to cause human disease,” the WHO said.
As part of the WHO’s planning, more than 200 scientists are assessing the pandemic risks from 30 families of viruses along with a core group of bacteria – and X. Ian Jones, professor of virology at the University of Reading in Britain, said it was almost certain that the next pandemic would be caused by a virus, perhaps one that jumps the species barrier.
“Viruses are the only things that can appear suddenly and spread most quickly,” he said.
A big concern for Paul Hunter, a researcher into infectious diseases at the University of East Anglia in Britain, is the trade in wild animal bushmeat, something that he and his colleagues have been writing about for two decades. “The problem is not local communities catching bushmeat and eating it. Even if they get something nasty, it’s unlikely in remote areas to spread rapidly,” he said.
“When you bring these animals into cities, if something makes the jump, then it’s much more likely to spread.
“That’s certainly what happened with Sars in 2003 and almost certainly what happened with Covid. That’s the big threat.”
The No 1 risk for Prof Jones is the potential for a new type of influenza to emerge.
Known flu pandemics began in 1889, 1918, 1957, 1968, 1977 and 2009, with the worst thought to have been the Spanish flu pandemic of 1918 to 1920, which killed tens of millions of people.
Further down the list, the Ebola virus has grabbed many headlines because of its high death rate, often above 50 per cent, among those who become infected with it.
However, as with the similar Marburg virus, which is also caused by a filovirus, Ebola does not pass easily enough between people to become a global concern.
Another cause for concern is the Nipah virus, which, the WHO said, is contracted by people in contact with infected bats or pigs. First identified in Malaysia in 1998, this paramyxovirus has recently caused a number of infections and deaths across India.
However, because the virus infects the brain and central nervous system tissues, Prof Hunter sees it as being less likely than others to spread easily.
The speed with which vaccines against the coronavirus were developed indicates that, if and when another pandemic emerges, the world may be in
British virologist Ian Jones says influenza or a virus that jumps the species barrier are the most likely suspects
a better position to respond. In a paper published in NPJ Vaccines journal in November, scientists from the pharmaceutical company Pfizer – which with BioNTech produced one of the coronavirus vaccines – said lessons from Covid-19 and influenza “underscore the importance of strengthening surveillance [and] investing in early-stage research on pandemic pathogens”.
Prof Jones said it was also important to minimise the risks of another pandemic emerging and, for him, agriculture is central to this.
“The amount of meat being consumed, the number of pigs bred and processed per unit of land mass and unit of population is huge,” he said.
“If things were able to get into that population of farm animals, there’s a huge opportunity for it amplify, and the chance for it to be transmitted to people.”