Singapore, March 1999. I was backpacking in southeast Asia, and my friend and I had just arrived in Singapore from Borneo. While on Borneo, we heard about a disease spreading uncontrollably in the rest of Malaysia, but it wasn’t until we reached Singapore that we realized the severity of the situation. Our plan was to cross the border between Singapore and Malaysia the next day. The problem was that some of the places where we’d planned to go were now out of reach because they had been placed under quarantine and martial law. And we couldn’t stay in Singapore; the illness was rapidly heading there as well. We needed to make a decision.

The epidemic in Malaysia in the fall of 1998 and the spring of 1999 was originally declared an outbreak of Japanese Encephalitis, a deadly zoonotic disease that spreads from pigs to humans with mosquitoes as the vector. But as the Malaysian government fought back against the outbreak, it became evident that what they were dealing with was not JE. Today we know that the epidemic in Malaysia was caused by a brand new virus, the lethal novel Nipah virus, first found in local fruit bats from where it moved on to pigs and from pigs to humans.

The Nipah virus might have been a novel virus, but the havoc it wreaked on Malaysian society was anything but new. Whenever an epidemic hits, the dynamics of that society are forever altered. Sometimes the effects are known immediately. Sometimes they take decades to manifest, even centuries.

Arguably the most famous pandemic in history is the Black Death, which swept across the European continent like wildfire between 1347 and 1350, killing nearly 50 percent of the population at the time. When the Black Death subsided, Europe was a changed place. So many people had died that the power dynamics between social groups changed everywhere, for the better and for the worse.

Overall, peasants and day laborers found their situation improving. So many had died, that those who survived could take advantage of the shortage of labor and demand higher wages. Combined with a decline in food prices, these groups experienced a general increase in their standard of living as well as a strengthening of their position against the nobility. In Sweden, this led to the peasantry becoming one of the Estates with their own political voice and agency when the Diet, the precursor to the modern Swedish parliament, was formed in the late 15th century. In Venice, a newcomer who moved in from the countryside no longer needed to live in the city for at least 25 years to become a citizen; after the plague, only one year was enough.

However, the situation did not improve for the peasantry in all parts of Europe. While the Swedish peasantry found themselves empowered, the experience of the English peasantry was quite the opposite. Here, the class that benefited the most from the Black Death was the yeoman, or independent, farmers, who used their access to cash to buy up land that lay abandoned. Between 1350 and 1500, regularly occurring plague outbreaks caused between 1,300 and 2,000 villages to disappear, either because they were abandoned or because decimated villages merged. Between 1450 and 1640, yeoman farmers bought as much abandoned land as they could and then closed it off to use for pasture on their manorial estates. This process is known as enclosure. Enclosure started happening in England already in the 12 th century, but with the many plague outbreaks, it gained momentum.

The yeoman class was so successful in their land grab that the English Crown interfered with legislation to prevent too much social mobility among the upper classes. The process of enclosure and the rigid class-based legislation that followed lies at the core of the British class system to this day. If you have ever wondered why the British Parliament still has a House of Lords in the 21 st century, part of the answer can be found in the process of enclosure enabled by several consecutive plague outbreaks.

When it comes to the United States, we don’t have to go far back in history to find evidence of how an epidemic causes social dynamics to change. We have evidence right here on our doorstep in the form of the gentrification of New York City.

Starting in 1981, gay men began dying from an unknown disease. Two years later, the virus that caused it was identified and named HIV. As Sara Schulman points out in her book The Gentrification of the Mind: Witness to a Lost Generation, there was an established correlation between the number of people infected by HIV in New York City’s East Village, West Village, Lower East Side, Chelsea, and Harlem and the gentrification rate of those areas.

Gentrification was already underway in New York City when the HIV/AIDS epidemic hit. When people started dying in large numbers, their apartments became vacant. With the partners of those who died unable to transfer the leases to themselves, and instead of other low-income and marginalized groups moving in, these leases went to affluent whites who could afford higher rents when they moved into the city from the suburbs. Similar to the impact of the plague on the enclosure movement in England, the HIV/AIDS epidemic sped up an already ongoing process, in this case gentrification; it, too, benefited affluent, already powerful groups at the expense of low-income groups living on the margins of society.

Back in Singapore, I looked for answers as for what to do in a local English-speaking newspaper. On the front page was a photograph of a soldier in the Malaysian army, standing with his firearm surrounded by pigs. In the end, we decided to head for the border as planned and the next day, we walked into Malaysia, hugging the east coast until we two weeks later crossed another border, this time into Thailand.

The effects of the Nipah virus outbreak on society in Malaysia were profound. Thousands of people died and millions of pigs were slaughtered before the new virus was discovered and the strategy to fight it changed. Parts of the Malaysian livestock business fell into a tailspin that lasted decades when pig farmers lost their livelihood and never reestablished their farms.

Recently, Politico asked 34 experts to predict the impact of the novel coronavirus pandemic on American society. They all gave different answers based on their areas of expertise, but what they all agreed on was that American society will not be the same.

As the cases of the Black Death, the Nipah outbreak, and the HIV/AIDS pandemic clearly demonstrate, major outbreaks of new illnesses change the power dynamics between groups in society. But what those changed dynamics will lead to will only be made clear to us in hindsight.