The next pandemic could spark from a disease with a 40 percent mortality rate within just two decades, top virologists say — warning Covid could have been just the tip of the pandemic iceberg.
DailyMail.com spoke to three virus experts who agreed a respiratory virus — spread via droplets from coughs and sneezes — was most likely to trigger the next fast-spreading disease that causes a global shutdown.
They said the infamous ‘disease X’ would most likely appear after a farm worker is infected with an animal-borne disease that mutates, but said they could not rule out the disaster would be sparked by a lab leak, a main theory as to the origin of the Covid pandemic.
It was also possible, they warned, for the outbreak to be even worse than the Covid pandemic, pointing to the 1918 influenza outbreak, which killed an estimated 50million people globally, compared to the seven million deaths from Covid.
Top culprits for the next pandemic, the experts speculated, were another coronavirus and avian influenza — a virus that infects birds but could possibly jump to humans. This disease has led to the slaughter of five million birds in the US this year in an attempt to prevent an outbreak. The experts, though, could not rule out other diseases like Ebola and outbreaks from insect-borne diseases like malaria and yellow fever.
There was a silver lining, however. They pointed to rapid advances in vaccine technology and antivirals as a sign the pharmaceutical industry would be able to rapidly rollout treatments against a pandemic disease when the next arises.
Below DailyMail.com reveals the opinions of three experts on what could cause the next pandemic and where it could come from:
Dr Leonard Mermel: Avian influenza
An infectious disease expert told DailyMail.com he believes the next pandemic will be caused by an avian influenza that mutates to spread rapidly between humans.
Avian influenza, also referred to as bird flu and H5N1, is a virus that primarily infects birds and tends to be spread via respiratory droplets. In rare cases, this virus can cross the species divide and infect mammals — including humans.
Dr Leonard Mermel from Brown University who has studied viruses for decades, said the next virus would likely appear when a poultry worker sick with human flu is infected with the avian strain at the same time.
Dr Leonard Mermel, an infectious diseases expert in Rhode Island, suggested the next pandemic could be caused by avian influenza
He explained: ‘These two viruses would then meet inside one of their cells and swap genes to create a new chimeric virus.’
A chimeric virus is one that contains genetic material from more than one virus.
The supervirus would then start to spread rapidly from human to human via respiratory droplets, he explained, spreading around the world and triggering the next pandemic.
The Rhode Island-based researcher warned in the beginning the strain could kill 30 to 40 percent of people it infects. For comparison, when Covid first emerged it had a fatality rate of five percent in the epicenter of Wuhan.
China is the most likely place the new virus would first appear, he said, because the country often records cases of human infection with avian influenza.
Data from the World Health Organization showed China has the third-highest number of human avian influenza cases recorded since 2003, at 55 infections.
It is behind Vietnam at 128 and Cambodia at 58, but the data is reliant on the number of cases submitted by each country — meaning the true toll may actually be much higher due to reporting delays and cases not being recorded.
Dr Mermel said: ‘Something that has concerned me for a long time is avian strains of influenza being transmitted in humans, that is of grave concern.
‘One particular strain is H5N1, which has made incremental changes over the past 10 to 20 years, but is yet to evolve to be easily transmitted from human-to-human.
‘It has gained some mutations so it can infect humans, which is scary. On the other hand, it has been around for a while, but I think we may be in a false sense of security at the same time. I think this is because these viruses can mutate very quickly.
‘It is certainly possible that it could cause a pandemic within the next 10 to 20 years, there would be consensus over that time span. But it could also take longer.’
Concerns over avian influenza have been increasing since 2022 and farms have been obligated to slaughter their entire poultry flock when just one bird tests positive for the virus since at least the 1980s.
Last year, an estimated five million chickens were slaughtered at farms across the US after avian influenza was detected in their flocks.
While this is a decline from the nearly 58million slaughtered in 2020, the recurring infections show the virus has found a way to survive the summer months and keep infecting flocks.
Last year, a prison inmate in Colorado tested positive for bird flu, but did not pass on the disease to others.
Dr Mermel also did not rule out it is ‘possible’ that a future pandemic could be triggered by a lab leak.
He said: ‘There is some evidence that one of the flu pandemics may have come from a lab in Russia.’
In 1977, a flu pandemic swept the world infecting millions of people and killing approximately 700,000.
It was caused by an H1N1 flu strain that emerged in the former Soviet Union that scientists said was a close match to an earlier strain that had circulated worldwide from 1946 to 1957.
Scientists at the time also noted the virus was infecting primarily younger people, who had never been exposed to this flu before, but mostly steering clear of older individuals who had lived through the initial outbreak and likely had a level of immunity.
Dr Mermel did suggest there was hope for the next pandemic, however, pointing to work to develop a universal flu vaccine and improvements in antivirals.
He said vaccine research would be turbo-charged in the event of another pandemic, using Covid’s vaccine development as an example and highlight it took just under a year for the first Covid vaccines to be made available after the virus emerged.
The above graphic shows how an avian influenza could be spread to humans, which may trigger the next pandemic
The above graphic shows the number of human infections with avian influenza reported in select countries by year
Dr Martin Hirsch: Avian influenza or coronaviruses
A virologist, a doctor who studies the management and prevention of infection, with more than 50 years of experience and who has worked in the most high-risk BSL-4 labs also said the next pandemic could be sparked by an Avian influenza, but added it could also begin with a coronavirus.
Dr Martin Hirsch, currently at Massachusetts General Hospital, warned the outbreak would likely be sparked when the viruses infect an intermediary animal — like a pig — and mutate, allowing them to be transmitted among humans.
A pandemic involving a coronavirus, the family of viruses to which Covid-19 belongs, could come from bats, he suggested, while the avian influenza would likely jump from domestic poultry.
Dr Martin Hirsch, who has more than 50 years of experience with viruses, said the next pandemic could be triggered by an avian influenza or coronavirus
He said this was likely to occur in either the US, Europe or China, where many animals are kept in dirty, cramped conditions — ripe for diseases to spread.
As for when it would happen, he said this was ‘very hard to predict’ but added flu outbreaks tend to be from 10 to 40 years apart.
The last major flu outbreak was the 2009 swine flu pandemic, when 1.4billion people were infected across the globe and 284,000 died from the respiratory infection.
‘I think coronaviruses and influenza would be most likely to cause the next pandemic,’ he told DailyMail.com.
He added: ‘But I wouldn’t rule out other viruses like HIV, Ebola, yellow fever, dengue, which are spread by different routes. They are certainly possibilities.
‘But, in my mind, I see a respiratory virus as having the greatest chance of quick worldwide transmission.
‘Certainly, Covid spread that way and also influenza spreads that way, and almost all the major and most recent pandemics and epidemics have been spread due to RNA viruses.’
An RNA virus is one that uses RNA protein strands as its building blocks instead of DNA. These viruses are more prone to mutations because RNA is less stable than DNA, raising the risk they could cause a pandemic.
Asked whether the next pandemic would be worse than the Covid outbreak, he said: ‘That is impossible to say. Nobody expected the last one, but it is possible.’
Like Dr Mermel, he also said it was ‘possible’ that a lab leak could start the next pandemic rather than a natural transmission event.
‘I don’t think we can rule that out,’ he said. ‘It is certainly possible that that kind of lab accident can occur and, on rare occasions, it has occurred,’ he told DailyMail.com
He added: ‘It is extremely important that we maintain rigorous procedures for safety at BSL-3 and BSL-4 labs. Scientists also should not be cavalier about what they work with and how they work with it.
‘I feel strongly that the “gain of function” laboratories should be closely monitored. Their experiments should not be done unless there is a very good reason and they are done under very rigorous containment procedures.’
Dr Elmer Gray: Insect-borne diseases
An entomologist, or a scientist specialized in the study of insects, has warned Americans cannot dismiss disease outbreaks caused by mosquitoes and ticks.
Dr Elmer Gray, at the University of Georgia, said warming temperatures coupled with globalization had generated a situation where the US must take it ‘year by year’ when it comes to disease outbreaks, though he stopped short of saying these kinds of viruses would spark an all-out pandemic.
He warned warmer overnight temperatures were fueling the growth of mosquito populations, leaving people at greater risk of infections.
Dr Elmer Gray, an entomologist at the University of Georgia, warned insects and ticks could spark outbreaks of infectious diseases in the coming years
He also said there was a risk of once-vanquished diseases returning to the United States, such as malaria and dengue fever.
This year, Florida, Texas and Maryland all recorded locally-transmitted cases of malaria, causing a flurry of concern among public health experts and officials.
Malaria, which is nearly always fatal if left untreated, was eradicated from the US in the 1950s — but cases continue to be imported every year via international travel.
Dengue fever — which can leave sufferers with a severe headache, pain behind the eyes and skin rashes — was eradicated in the US in the 1940s and 50s but there was a resurgence in the early 2010s.
Dr Gray said another, entirely ‘unknown disease’ spread by mosquitoes could also take the US by surprise in the coming years.
‘Every year has the potential for an insect-borne disease outbreak,’ he told DailyMail.com.
‘This year, we didn’t have a tremendous amount of hurricanes… but all the eggs deposited this year are still there and will be ready for the next hurricane for sure.
‘What really concerns me though is the longer warm seasons.
‘At night, the water stays warm now allowing those larvae to grow so much faster and that speeds up their life cycle — raising mosquito numbers.’
He added: ‘Insect-borne diseases are not going to cause the next pandemic, but there is definitely potential for outbreaks and for large areas of concern.’
He pointed to several examples from within the last two decades of insect-borne diseases being introduced to the United States and quickly taking root.
West Nile Virus, which can cause inflammation of the brain and lifelong disability, now causes an estimated 400,000 infections and 130 deaths per year in the US.
It arrived in the US in 1999 in New York and within five years had spread across the entire country. Despite regularly spraying pesticides to stop the disease — which is carried by mosquitoes — from spreading, it has now become endemic across the country.