Future Pandemics: When, where, and what will the next pandemic be?

Pandemics in history

A brief history of outbreaks

Diseases that spread from one person to another—known as communicable diseases—date back to humankind's hunter-gatherer days. It wasn't until humans began growing crops, forming societies, and waging war against one another that diseases were able to spread more widely and turn into epidemics and pandemics.

• Athenian Plague, 430 BC: The first recorded pandemic took place as the city of Athens was under siege by Sparta during the Peloponnesian War. The plague, still of unknown origin, led to the death of about 25 percent of the region's population.
• Antonine Plague, 165 AD: Spreading throughout the Roman Empire at the height of its power, the Antonine Plague was likely caused by an outbreak of smallpox. Historians believe the spread began in China, and Roman troops who had been fighting in the East are believed to have brought the disease back with them upon returning home.
• Justinian Plague, 541: Long considered a precursor to the more infamous Black Plague, the connection between the two were confirmed only recently. Scientists in 2013 extracted DNA from skeletal remains in a sixth century burial site and found the same microbial pathogen that caused the Black Plague. All told, the Justinian Plague wiped out nearly half of the world's population at the time.
• Black Plague, 1346: Though its total death toll is still debated among historians, the Black Plague was undoubtedly one of the worst pandemics in human history. Spread by flea-infested rats, the plague wiped out tens of millions of people in Europe. The continent's population didn't fully recover until over a century later. The plague has never been fully eradicated, although it can now be treated effectively with antibiotics.
• Seven Cholera Pandemics, 1817-present: This bacterial disease that causes acute diarrheal illness has led to several pandemics throughout the Nineteenth and Twentieth Centuries and all over the globe. The latest pandemic, which remains ongoing today, originated in Indonesia in 1961 and ravaged the continent of Africa during the 1990s. People can get cholera by consuming contaminated water or food, or coming into contact with the fecal matter of a person who's sick with the disease.
• Spanish Flu, 1918: Caused by an H1N1 virus with genes of avian origin, the Spanish Flu of 1918 killed about 50 million people worldwide, and lowered the US life expectancy by 12 years. Despite its name, this deadly flu virus actually originated in the United States, and spread rapidly throughout the world as US soldiers were deployed to Europe during World War I.

How likely is a global pandemic?

Future pandemics are inevitable, but we can reduce the risk

Humans have made amazing advances in science and medicine in the past several decades. At the same time that these innovations and breakthroughs have occurred, however, the likelihood of diseases to spread and turn into epidemics or pandemics has increased. Public health experts say that this increased risk is the result of globalization—the growing interconnectedness of countries and their economies from around the globe.

There are many aspects of our globalized society-like frequent travel, growing urbanization, climate change, and our global food system's reliance on factory farming-that all contribute to the inevitability of the next pandemic.

While there's no way to stop the next pandemic in its tracks, experts have published practical steps we can take to reduce the risk. A recent report in the journal Science says that reducing deforestation, more properly regulating the wildlife trade and hunting, and more closely surveilling zoonotic pathogens-which can spread from animals to humans-are three key strategies that could help us become better prepared for the next pandemic than we were for COVID-19.

Greater meat consumption is also a factor driving concerns about the next pandemic. In 2020, Humane Society International published a paper outlining the various ways industrialized agriculture puts the world at a greater risk:

• As factory farms grow larger and encroach on the once remote wilderness, domesticated animals are more likely to contract viruses from wild animals.
• On cruelly overcrowded farms, disease spreads rapidly from animal-to-animal.
• Farmed animals are transported throughout countries and around the world, regularly coming into contact with humans and creating the potential for viruses to spill into human populations.

Additionally, scientists have cited the overuse of antibiotics in chicken farming in particular as the leading cause of resistance development in bacteria. One global study showed that in E. coli sampled from chickens across eight different countries, over 40% showed resistance to four different classes of antibiotics. Any reduction in antibiotic usage will reduce the chances of a deadly antibiotic resistant bacteria developing that could then spread to other species, including humans. Chickens raised for meat in higher welfare settings use three to five times fewer antibiotics than the current intensively farmed birds on factory farms.

The conclusion is clear: moving towards higher welfare standards for animal farming, and ultimately reducing the global demand for animal-based products, are essential to mitigating the risks posed by the next pandemic.

When could the next pandemic happen?

Scientists aren't able to pinpoint precisely when the next pandemic will occur. However, they do predict that most of us will probably experience another pandemic within our lifetime.

Is there another pandemic coming after COVID-19?

According to the Center for Global Development, the annual likelihood of a pandemic is around 2-3%. That means there's a 47-57% probability that the world will experience another deadly pandemic before 2050.

What could the next pandemic come from?

What role will climate change play in the next pandemic?

Scientists are already finding ways that climate change is making pandemics more likely. As temperatures near the equator get more extreme, and as wild animal species see their habitats destroyed from development and deforestation, they have little choice but to look for new, more hospitable homes. As they head toward the poles, they're more likely to encounter other species—including humans. When humans have greater contact with wild animals, there's more opportunities for viruses, bacteria, and other pathogens to spillover into the human population.

Humans—especially through developing large-scale farms—are encroaching into the once remote wilderness too, further fueling the emergence of new viral diseases.

Climate change also creates better conditions-higher temperatures and increased rainfall-for infectious diseases to spread. Researchers have already observed this trend with tick-borne diseases like Lyme disease and mosquito-borne diseases like malaria.

What role will zoonotic disease play in the next pandemic?

What is a zoonotic disease?

Zoonotic diseases, or zoonoses, are diseases that spread from animals to humans. They may be caused by bacteria, parasites, viruses, or fungi. Rabies, Lyme disease, ringworm, and salmonellosis are some common examples of zoonotic disease.

Zoonotic diseases are on the rise

Zoonotic diseases have been around for about as long as humans and animals have shared the earth together. However, in recent history, zoonotic diseases have "dominated" infectious disease events. According to the Council on Foreign Relations, around 60% of known infectious diseases are zoonotic in origin, as are about 75% of new or emerging communicable diseases. Globally, zoonotic diseases are responsible for billions of illnesses and millions of deaths annually.

Key drivers of zoonotic disease

Some of the key drivers in the spread of zoonotic diseases include increases in human population, deforestation and destruction of animals' natural habitats, intensive agricultural practices, and the rise of wildlife trade and wild meat consumption. Simply put, animals on overcrowded farms are more stressed. This stress lowers their immune system's ability to fight off diseases. Once one animal gets sick, the other creatures they live so close to are probably going to get sick too. And every time these sick animals-or areas contaminated by these animals, such as feces within bodies of water-come into contact with humans, there's a risk that whatever virus is affecting the animals will leap to the human.

Where could the next outbreaks occur?

Outbreaks are random events, so it's impossible to say precisely where the next major disease outbreak will come from. However, researchers have observed that a significant percentage of communicable diseases jump from non-human animal populations into human populations in West and Central Africa, as well as South and Southeast Asia. These regions share some commonalities that make them more susceptible to zoonotic outbreaks. Factors like rapidly expanding human settlements, widespread poverty, intensifying agricultural development, and the exploitation of natural resources all put these regions at a higher risk.

Unfortunately, these characteristics create a vicious cycle in which the world's poorest peoples are disproportionately affected by communicable diseases, yet lack the resources necessary to detect a new outbreak before it has the opportunity to spiral out of control.

What could the next pandemic be?

Epidemiologists tend to prioritize diseases that could lead to "the next pandemic" based on how quickly they spread and how effectively humans can treat them. While there are some broad categories of viruses that groups like the World Health Organization (WHO) are monitoring closely, there's always the possibility of an currently unknown virus emerging, what experts sometimes refer to as "Disease X."

Influenza

Influenza, or the flu, is a highly contagious illness that can affect the nose, throat, and lungs. There are a range of influenza viruses that are especially communicable in human, birds, and pig populations. Currently, scientists have particular concerns about avian influenza, which tends to originate in wild waterfowl, but is currently tearing through farmed bird populations as well, increasing its risk of spilling over and affecting humans. Avian influenza has already been diagnosed in mammals—including at least one case of a human who contracted bird flu in the US.

Coronavirus

Aside from the 2019 novel coronavirus, COVID-19, there are four human coronaviruses endemic (regularly, predictably occurring) to human communities. For the most part, these viruses cause mild to moderate respiratory illnesses. However, as made clear during the height of the COVID-19 pandemic with variants like delta and omicron, viruses are constantly changing and evolving. Within the past 20 years, humans have experienced three major outbreaks of different coronaviruses.

Ebola

A zoonotic disease spread by bats, porcupines and non-human primates, ebolaviruses were first recorded in the mid-1970s near the Ebola River in the Democratic Republic of the Congo. Ebolaviruses have since periodically emerged and infected humans  throughout the continent of Africa. The worst outbreak yet took place from 2014 to 2016. Ebolavirus diseases are very deadly, with an average fatality rate of 50%, and some rates as high as 90% during some outbreaks.

Will the next pandemic be deadlier?

As COVID-19 cases are finally reaching manageable levels, WHO director-general Tedros Adhanom Ghebreyesus has warned that countries around the world must stay vigilant, because the next serious outbreak could be even deadlier.

"The threat of another variant emerging that causes new surges of disease and death remains, and the threat of another pathogen emerging with even deadlier potential remains," he said during a meeting in Switzerland in May 2023.

Are we better prepared for the next pandemic?

Scientists, doctors, and other experts have been saying it for a long time-but especially in the past three years: We need to make some serious changes to better prepare for the next pandemic. Dr. Tom Inglesby, director of the Johns Hopkins Center for Health Security, wrote in a recent New York Times op-ed that to better prepare for the next pandemic, governments around the world must invest in several areas:

• Better vaccine research, ideally allowing immunization to begin within the first 100 days of a new pandemic
• Forming contracts with diagnostic companies so that free testing kits can get distributed very quickly when a new disease is detected in humans
• Stockpiling high-quality, personal protective gear like masks
• Improving indoor air quality with better filters, more outdoor air intake, and new technologies to mitigate the spread of pathogens
• Increasing oversight and safety measures in research labs.

How do we monitor for the next outbreak?

Experts say that by the time sick people start showing up to hospitals with new disease symptoms, it's too late. That's why public health experts are trying to conduct surveillance in "disease hot spots," to detect a new virus before it has the chance to infect many people. By monitoring in areas where wild animal diseases can easily spillover into human populations, experts could catch the warning signs of a growing outbreak, before it turns into an epidemic, or worse a pandemic.

How our diet contributes to pandemic risks

It's well-known in the scientific community that industrial-scale agriculture is fueling serious risks to public health at a global scale. Factory farms are densely packed facilities where diseases can spread like wildfire.

As these massive farms expand to meet the growing demand for animal products, they contribute to concerns like antimicrobial resistance, climate change, and the spread of zoonotic diseases, all of which make it harder to prevent the next pandemic.

Dr. Michael Greger, a physician and author who has written about the growing risk of avian influenza, illustrates just how directly tied the meat industry is to global health risks:

"When we overcrowd animals by the thousands, in cramped football-field-size sheds, to lie beak to beak or snout to snout, and there's stress crippling their immune systems, and there's ammonia from the decomposing waste burning their lungs, and there's a lack of fresh air and sunlight-put all these factors together and you have a perfect-storm environment for the emergence and spread of disease."

How do we prevent future pandemics?

There seems to be no single catch-all solution that will definitely prevent the next pandemic. However, humans can take a series of steps to mitigate the toll of the next pandemic. Rigorous disease monitoring in high-risk areas, investing into vaccine research, reducing deforestation and habitat destruction, and switching to a humane, plant-based diet are just some of the many things humans can do to reduce the risk.

What is the current pandemic prevention strategy?

Prior to 2020, less than half of UN member states had developed respiratory pathogen pandemic preparedness plans. The COVID-19 pandemic, fortunately, has taught governments around the world that they need to do a better job preparing for the next public health emergency. In April of 2023, WHO announced a new initiative to help countries develop plans to monitor, prepare for, and respond to outbreaks of respiratory pathogens such as influenza or coronaviruses.

In the United States, the Biden-Harris Administration launched a national biodefense strategy and implementation plan in late 2022. The plan focuses on improving lab safety and global health security, as well as detecting infectious diseases early. One of the newest tools for early detection is the Center for Forecasting and Outbreak Analytics, which acts as a "national weather service" for infectious diseases.

What you can do

Mitigating the risks of the next pandemic is a tall order, with many decisions being made at the highest levels of governments around the world, and by science and medicine's top experts. However, you can band together with other activists to make your voice heard!

At The Humane League, we work hard to hold corporations and elected officials accountable for how their actions affect the wellbeing of animals and humans alike. There are plenty of ways for you to get involved in that effort.

Join THL's Fast Action Network, which gives you a way to take part in various impactful online activities, such as signing petitions, emailing decision-makers, or applying pressure via social media. You can also keep an eye on our Events page to see what's happening in your area or online. And of course, you can join us as a volunteer.