When I wrote my book, For a Moment of Taste, COVID-19 did not yet exist. I warned that the time was ripe for a deadly pandemic, but I did not imagine that my prediction would become a reality in a matter of months.

Even nearly a year into the crisis, there is still so much to learn. But there is one thing we know for certain: factory farms and live-animal markets are putting our lives at risk.

Public health experts overwhelmingly believe that COVID-19 first infected humans at a live-animal meat market in China.

Such markets are blood-soaked slaughterhouses where members of the public can choose live animals, from dogs to pangolins, who are then killed while the customer waits.

Conditions at these “wet markets” are ghastly. As Peter Li, associate professor at the University of Houston–Downtown, describes, “The cages are stacked one over another. Animals at the bottom are often soaked with all kinds of liquid.

Animal excrement, pus, blood.” It’s little wonder live-animal markets are breeding grounds for disease where viruses can easily spread. But factory farming plays a role in driving zoonotic diseases (i.e. those of animal origin), too, and not just in China.

As I write this, outbreaks of various types of avian influenza – that is, bird flu – are rapidly spreading across India.

At least ten states have confirmed cases, and the virus is expected to continue to spread. Countless chickens are being slaughtered in an attempt to contain the H5N1 and H5N8 strains.

It was just over 20 years ago that the first-ever human infections of the H5N1 strain of bird flu coincided with infections found in chickens at farms and live-animal meat markets in Hong Kong.

The Centers for Disease Control and Prevention (CDC) notes that most human infections with this virus have occurred through contact with infected birds. Live poultry markets and the crowded factory farms on which chickens are raised facilitate that contact. H5N1 is deadly serious: when humans are infected, the mortality rate is about 60%.

Worldwide, almost 600,000 people died from H1N1 swine flu just during the first year the virus circulated, according to the CDC.

Its roots were traced to a strain that existed in US pig farms in 1998. In the previous decade, the pig population in one state alone jumped from 2 million to 10 million, and the animals were jammed onto fewer farms, creating an easier opportunity for disease spread.

Over 70% of the world’s farmed animals spend their lives in misery on factory farms. These industrialised warehouses jam pigs, chickens, cows, and other animals by the hundreds, thousands, or even millions in cages, crates, or pens barely larger than their own bodies to supply the demand for meat, eggs, and milk. A former executive director of the Pew Commission on Industrial Animal Farm Production calls these farms “super-incubators for viruses”.

And so, in an effort to prevent illness in animals, globally, antibiotics are used more heavily in animal agriculture than in humans – but this comes with consequences. Health officials have sounded the alarm that this overuse of antibiotics in animals is contributing to antibiotic resistance in humans – when life-saving antibiotics become less effective.

According to the World Health Organization, already, 700,000 people worldwide die from infection with drug-resistant bacteria each year.

As vaccines are being rolled out, the better management of this pandemic might be in sight, but in order to prevent the spread of future zoonotic diseases, it’s high time for a global shift in how we treat the animals with whom we share this planet. The best way to begin is to reduce the demand for factory farms and live-animal markets by going vegan.

Poorva Joshipura is senior vice president of international affairs for PETA Foundation UK.