The History of Pandemics
Pan·dem·ic /panˈdemik/ (of a disease) prevalent over a whole country or the world.
As humans have spread across the world, so have infectious diseases. Even in this modern era, outbreaks are nearly constant, though not every outbreak reaches pandemic level as COVID-19 has.
Today’s visualization outlines some of history’s most deadly pandemics, from the Antonine Plague to the current COVID-19 event.
A Timeline of Historical Pandemics
Disease and illnesses have plagued humanity since the earliest days, our mortal flaw. However, it was not until the marked shift to agrarian communities that the scale and spread of these diseases increased dramatically.
Widespread trade created new opportunities for human and animal interactions that sped up such epidemics. Malaria, tuberculosis, leprosy, influenza, smallpox, and others first appeared during these early years.
The more civilized humans became – with larger cities, more exotic trade routes, and increased contact with different populations of people, animals, and ecosystems – the more likely pandemics would occur.
Here are some of the major pandemics that have occurred over time:
|Name||Time period||Type / Pre-human host||Death toll|
|Antonine Plague||165-180||Believed to be either smallpox or measles||5M|
|Japanese smallpox epidemic||735-737||Variola major virus||1M|
|Plague of Justinian||541-542||Yersinia pestis bacteria / Rats, fleas||30-50M|
|Black Death||1347-1351||Yersinia pestis bacteria / Rats, fleas||200M|
|New World Smallpox Outbreak||1520 – onwards||Variola major virus||56M|
|Great Plague of London||1665||Yersinia pestis bacteria / Rats, fleas||100,000|
|Italian plague||1629-1631||Yersinia pestis bacteria / Rats, fleas||1M|
|Cholera Pandemics 1-6||1817-1923||V. cholerae bacteria||1M+|
|Third Plague||1885||Yersinia pestis bacteria / Rats, fleas||12M (China and India)|
|Yellow Fever||Late 1800s||Virus / Mosquitoes||100,000-150,000 (U.S.)|
|Russian Flu||1889-1890||Believed to be H2N2 (avian origin)||1M|
|Spanish Flu||1918-1919||H1N1 virus / Pigs||40-50M|
|Asian Flu||1957-1958||H2N2 virus||1.1M|
|Hong Kong Flu||1968-1970||H3N2 virus||1M|
|HIV/AIDS||1981-present||Virus / Chimpanzees||25-35M|
|Swine Flu||2009-2010||H1N1 virus / Pigs||200,000|
|SARS||2002-2003||Coronavirus / Bats, Civets||770|
|Ebola||2014-2016||Ebolavirus / Wild animals||11,000|
|MERS||2015-Present||Coronavirus / Bats, camels||850|
|COVID-19||2019-Present||Coronavirus – Unknown (possibly pangolins)||6.9M (Johns Hopkins University estimate as of March 1, 2023)|
Despite the persistence of disease and pandemics throughout history, there’s one consistent trend over time – a gradual reduction in the death rate. Healthcare improvements and understanding the factors that incubate pandemics have been powerful tools in mitigating their impact.
March 1, 2023 Update: Due to popular request, we’ve also visualized how the death tolls of each pandemic stack up as a share of total estimated global populations at the time.
Wrath of the Gods
In many ancient societies, people believed that spirits and gods inflicted disease and destruction upon those that deserved their wrath. This unscientific perception often led to disastrous responses that resulted in the deaths of thousands, if not millions.
In the case of Justinian’s plague, the Byzantine historian Procopius of Caesarea traced the origins of the plague (the Yersinia pestis bacteria) to China and northeast India, via land and sea trade routes to Egypt where it entered the Byzantine Empire through Mediterranean ports.
Despite his apparent knowledge of the role geography and trade played in this spread, Procopius laid blame for the outbreak on the Emperor Justinian, declaring him to be either a devil, or invoking God’s punishment for his evil ways. Some historians found that this event could have dashed Emperor Justinian’s efforts to reunite the Western and Eastern remnants of the Roman Empire, and marked the beginning of the Dark Ages.
Luckily, humanity’s understanding of the causes of disease has improved, and this is resulting in a drastic improvement in the response to modern pandemics, albeit slow and incomplete.
The practice of quarantine began during the 14th century, in an effort to protect coastal cities from plague epidemics. Cautious port authorities required ships arriving in Venice from infected ports to sit at anchor for 40 days before landing — the origin of the word quarantine from the Italian “quaranta giorni”, or 40 days.
One of the first instances of relying on geography and statistical analysis was in mid-19th century London, during a cholera outbreak. In 1854, Dr. John Snow came to the conclusion that cholera was spreading via tainted water and decided to display neighborhood mortality data directly on a map. This method revealed a cluster of cases around a specific pump from which people were drawing their water from.
While the interactions created through trade and urban life play a pivotal role, it is also the virulent nature of particular diseases that indicate the trajectory of a pandemic.
Scientists use a basic measure to track the infectiousness of a disease called the reproduction number — also known as R0 or “R naught.” This number tells us how many susceptible people, on average, each sick person will in turn infect.
Measles tops the list, being the most contagious with a R0 range of 12-18. This means a single person can infect, on average, 12 to 18 people in an unvaccinated population.
While measles may be the most virulent, vaccination efforts and herd immunity can curb its spread. The more people are immune to a disease, the less likely it is to proliferate, making vaccinations critical to prevent the resurgence of known and treatable diseases.
It’s hard to calculate and forecast the true impact of COVID-19, as the outbreak is still ongoing and researchers are still learning about this new form of coronavirus.
Urbanization and the Spread of Disease
We arrive at where we began, with rising global connections and interactions as a driving force behind pandemics. From small hunting and gathering tribes to the metropolis, humanity’s reliance on one another has also sparked opportunities for disease to spread.
Urbanization in the developing world is bringing more and more rural residents into denser neighborhoods, while population increases are putting greater pressure on the environment. At the same time, passenger air traffic nearly doubled in the past decade. These macro trends are having a profound impact on the spread of infectious disease.
As organizations and governments around the world ask for citizens to practice social distancing to help reduce the rate of infection, the digital world is allowing people to maintain connections and commerce like never before.
Editor’s Note: The COVID-19 pandemic is in its early stages and it is obviously impossible to predict its future impact. This post and infographic are meant to provide historical context, and we will continue to update it as time goes on to maintain its accuracy.
Update (March 1, 2023): We’ve adjusted the death toll for COVID-19, and will continue to update on a regular basis.
Innovation in Virology: Vaccines and Antivirals
Vaccine development has grown six-fold since 1995. Learn how virology, the study of viruses, is driving innovation in the healthcare industry.
Innovation in Virology: Vaccines and Antivirals
The COVID-19 pandemic affected millions of people worldwide and brought renewed focus to virology—the study of viruses.
However, impact made by viruses extends far beyond the SARS-CoV-2 virus that causes COVID-19. There are 24 viruses that have each infected more than 80 million people globally, from hepatitis to influenza.
In this graphic from MSCI, we uncover innovation in vaccines and antivirals and the related market opportunities.
What is a Virus?
A virus is a microscopic infectious agent that replicates within living cells. It may cause disease in its host. New viruses can emerge at any time as a result of mutation, or when viruses transfer from animals to humans.
Through virology, scientists are continuously finding new ways to fight against infectious diseases. Two main types of anti-infectives are available: vaccines and antivirals.
Rapid Innovation in Vaccines
Vaccines are substances designed to prevent people from getting infected with a disease or experiencing serious symptoms.
The number of vaccines has increased dramatically over the last three decades. From 2020 to 2021 alone, the number of approved vaccines or clinical candidates jumped by 13%.
|Year||Vaccines Approved or in Development|
Data is a snapshot in time and reflects all vaccines ever approved (and not taken off the market) plus all vaccines in development as of the noted year (for which a trial has not been canceled).
Not only that, it’s possible to have shorter approval timelines. COVID-19 vaccines were approved within 11 months, much more quickly than the 2000-2020 average of 10 years.
In the time between an outbreak and vaccine development, antivirals can play a vital role.
Antivirals: The Second Line of Defense in Virology
Antivirals are drugs that slow or prevent the growth of a virus and treat disease symptoms. They are especially important tools for diseases that do not have an associated vaccine.
In 2021, there were nearly six times as many approved antivirals as there were in 1995. Not only that, antiviral uses have grown to include the potential prevention and treatment of HIV, COVID-19, and a number of other diseases.
in the U.S.
The potential prevention (prophylaxis) and treatment of the same virus are counted as separate uses. Data is cumulative and reflects all antivirals ever approved (and not taken off the market) and all reasons ever approved for using antivirals (that have not been rescinded).
Innovation in virology—and the potential for future developments—is leading to a growing industry.
Expanding Market Opportunities
With opportunities growing and approval times shortening, more companies are entering the market.
|Year||Companies Developing Vaccines/Antivirals|
Data is a snapshot in time and reflects all companies developing vaccines or antivirals as of the noted year. If a company stops being active in the space or ceases to exist, they are removed from the total.
As they work to develop new vaccines and antivirals, companies are conducting clinical trials for many diseases beyond COVID-19 such as respiratory infections and sepsis.
Virology is leading to a number of groundbreaking technologies and therapies, transforming healthcare along the way.
Explore the MSCI Virology Index now.
You may also like
Politics6 months ago
Timeline: Cannabis Legislation in the U.S.
At the federal level, cannabis is illegal, but state laws differ. This graphic looks at the timelines of cannabis legislation in the U.S.
Science1 year ago
Visualizing the Relationship Between Cancer and Lifespan
New research links mutation rates and lifespan. We visualize the data supporting this new framework for understanding cancer.
Healthcare2 years ago
Visualizing How COVID-19 Antiviral Pills and Vaccines Work at the Cellular Level
Despite tackling the same disease, vaccines and antiviral pills work differently to combat COVID-19. We visualize how they work in the body.
Markets1 week ago
Ranked: The Highest Paid CEOs in the S&P 500
Retail3 weeks ago
Visualizing the Number of Costco Stores, by Country
Markets1 week ago
Charted: Market Volatility at its Lowest Point Since 2020
Culture3 weeks ago
Ranked: Which Countries Drink the Most Beer?
Markets1 week ago
Mapped: The Migration of the World’s Millionaires in 2023
Maps3 weeks ago
Mapped: The Deadliest Earthquakes of the 21st Century
Countries1 week ago
Charted: The World’s Biggest Oil Producers
Inequality4 weeks ago
Visualizing the World’s Growing Millionaire Population (2012-2022)