What is Disease X?
Don’t panic! Disease X does not exist yet – but it could one day. Disease X is the label that the World Health Organization uses to refer to any currently unknown infectious condition that is capable of causing an epidemic or – if it spreads across multiple countries, becoming a pandemic. The term, coined in 2017, can be used to mean a newly discovered pathogen or any known pathogen that has recently acquired pandemic potential. By the latter definition, covid-19 was the first Disease X. But there could be another in the future.
Why are people talking about this now?
The World Health Organization has been warning global leaders about the risks of future pandemics at the annual meeting of the World Economic Forum, held this week in Davos, Switzerland. “Some people say this could create panic,” says WHO Director-General Tedros Adhanom Ghebreyesus. “No. It is better to anticipate something that could happen – because it has happened many times in our history – and prepare for it.”
What could be the next Disease X?
We don’t know – that’s why it’s called Disease X. Coronaviruses, a large group of viruses, have long been seen as prime candidates for producing a new pandemic, even before the Covid-19 outbreak. This is because the new coronavirus was not the first dangerous pathogen from this group. In 2002, a different coronavirus began to spread in China. It caused a form of pneumonia called SARS, which killed about 1 in 10 infected people before being halted by strict infection control measures. Another, even deadlier coronavirus, called MERS, occasionally emerges, causing pneumonia that kills 1 in 3 infected people. However, recent work suggests that SARS and MERS would have more difficulty triggering a new pandemic because almost everyone in the world now has antibodies against the virus that causes covid-19, and these seem to confer partial protection against most other pathogens in the coronavirus family.
Are there other contenders with pandemic potential?
Many diseases, some well-known and others less familiar, could pose a global threat. Strains of influenza have caused global pandemics several times in the past, including one of the deadliest disease outbreaks on record, the “Spanish flu” of 1918. A virulent strain of avian influenza is currently sweeping the globe and occasionally spreading from birds to mammals, causing mass deaths. Just this week, this flu was blamed for the deaths of 17,000 seal pups in Argentina last October. Then there are other viruses, such as Ebola, which causes severe hemorrhaging, and Zika, transmitted by mosquitoes, which can cause babies to be born with neurological diseases if the infection occurs during pregnancy. The WHO updated its list of pathogens with the highest pandemic potential in 2022.
What can we do to prevent Disease X?
There is good news: the covid-19 pandemic may have made it easier to prevent any future Disease X. Covid-19 spurred the development of new vaccine designs, including those that can be quickly repurposed to target new pathogens. It led, for example, to the advent of mRNA-based vaccines. This formula contains a small piece of genetic material that prompts the body’s immune cells to produce the coronavirus’s “spike” protein – but it could be updated to make the cells produce a different protein simply by rewriting the mRNA sequence.
Source: New Scientist