AS THE WORLD enters the second year of a deadly pandemic, it’s hard to shake the feeling that each nation is largely on its own. From the spectacle of countries hoarding vaccines to the seemingly endless travel restrictions, the disease seems to have fueled nationalism, undercut international cooperation and heightened geopolitical tensions.

Yet even at this stage of the pandemic, history gives reason for hope. The long record of “vaccine diplomacy” confirms that diseases don’t always divide nations. In fact, the very act of fighting pathogens can foster comity and collaboration between them.

The story of vaccine diplomacy arguably begins with the “speckled monster,” smallpox. For centuries, the virus plagued humanity, killing between 20% and 60% of its victims and leaving survivors horribly disfigured or blind.

Enter Edward Jenner, a doctor in 18th century Britain. Jenner observed that milkmaids rarely caught smallpox. Some milkmaids ascribed this protection to the fact that most had already caught a related, but largely harmless, disease: cowpox. Jenner speculated that if he gave someone cowpox, it would confer immunity against smallpox.

He was right. Jenner called this method vaccination: “vacca” is Latin for cow. Though many assailed Jenner, his advocacy of vaccination gained prominent supporters throughout Britain, and eventually, the rest of the world in the opening decades of the 19th century.

The historian Michael Bennett recently published a book that details this remarkable campaign, which took place during a period of intense warfare between Britain and France, as well as other conflicts around the world. Jenner, however, was not deterred. During the Napoleonic Wars, he famously declared to his French counterparts, “The sciences are never at war.”

This may sound hopelessly naive, but Jenner and a growing network of allies around the world began shipping vaccines between warring countries, putting public health ahead of national conflicts. Jenner soon found himself tapped to serve as an unofficial diplomat between Britain and France, trusted by both countries.

Vaccination transformed diplomatic relations around the world. Prior to Jenner, countries couldn’t do much to help each other fight disease. Conventional medicine was largely useless, and all the money in the world couldn’t stop smallpox. But vaccines could, and countries soon began wielding them as a way to buy good will.

This was altruism leavened with national self-interest. In fact, Jenner and other British authorities hoped to make vaccination integral to managing the nation’s growing empire. Jenner hoped “soon to see Societies form’d throughout the Empire for the Extermination of the Smallpox” comparable to the medical infrastructure he was building at home.

Other countries took notice. As early as 1801, the United States began offering smallpox vaccinations to visiting dignitaries from Indian tribes. President Thomas Jefferson even sent vaccines westward with the famed Lewis and Clark expedition, though they apparently spoiled before they could be used. 

France took vaccine diplomacy farther than most. After the microbiologist Louis Pasteur developed a vaccine that prevented rabies — a dread disease that killed everyone who contracted it — the French government began building laboratories throughout its colonies in order to administer the vaccine on a mass scale.

While it’s easy to write off these kinds of efforts as self-interested imperial meddling, the scientists who promoted these vaccination programs genuinely believed that vaccines could transcend national differences. Pasteur, for example, famously proclaimed that “science knows no country.”

This was more an ideal than a reality, but Pasteur was onto something. At the height of the Cold War, the US and the Soviet Union inched perilously close to nuclear conflict on several occasions. They also managed to collaborate on a vaccine for polio, a disease that left many children paralyzed or dead.

In the 1950s, the US began administering polio vaccines developed by Jonas Salk. These relied on dead versions of the virus to elicit an immune response. Though sound, this method had significant drawbacks: multiple vaccinations and boosters. Worse yet, many parents refused to let their children be vaccinated after a faulty batch of vaccines infected patients with polio.

The virologist Albert Sabin disagreed with Salk’s approach, arguing for use of a live but attenuated version of the virus. Unfortunately, there was neither a will nor a way to test it on American children, given that many had been vaccinated already with Salk’s serum and few parents had the stomach for further experiments.

But there was another country willing to take a chance: the Soviet Union. In 1956, a husband-and-wife team of Soviet virologists paid Sabin a visit, sparking what would turn into a sustained collaboration. As FBI and KGB agents hovered over the two teams, the Americans prepared an attenuated strain of polio to inject into Soviet children.

As the two countries fought proxy wars around the globe, they nonetheless collaborated on one of the largest vaccine trials in human history. The Soviet Union and Eastern Bloc countries ultimately vaccinated over 100 million people, mostly children. This campaign, which a British medical journal dubbed a “Blitzkrieg against polio,” demonstrated that the Sabin vaccine was safe, effective, and capable of being produced quickly on a mass scale.

The US quickly pivoted, shifting to the Sabin method of vaccination. The two countries then began distributing the polio vaccine around the world. Much of this was classic vaccine diplomacy, with each country buying goodwill by delivering the miracles of modern medicine. But whatever the intent, the world’s children became the beneficiaries.

The same was true of the superpowers’ collaboration on eradicating smallpox. After the Soviet Union developed freeze-dried versions of a smallpox vaccine, the two countries then worked together on what remains the most successful vaccination program in human history, completely eliminating smallpox.

These successful collaborations underscore a basic fact: Geopolitical rivalries need not impede an effective global response to deadly diseases.

It’s a lesson worth heeding now, as the pandemic enters its second deadly year. So long as countries try to beat COVID on their own, they’ll fail. But if they revive the model of cooperation that rid the world of diseases like smallpox and polio, we might actually beat this thing.