The Great Serum Run

In the winter of 1925, Nome was about as remote as an American town could be. A former gold-rush boomtown of around 1,400 people on the edge of the Bering Sea, just below the Arctic Circle, it spent seven months of every year sealed off from the world: from November the sea froze solid, and no ship could reach it until summer. There was no railway and no road. The open-cockpit aircraft of the day were useless in an Alaskan winter — their engines simply would not run at fifty degrees below zero. The only land link was the dog-sled trail to the railhead at Nenana, 674 miles away — a mail journey that normally took the best part of a month.

The town had one doctor, Curtis Welch, and a small hospital with four nurses. In December and January, children began coming to him with sore throats and fever. He treated them for tonsillitis — until a three-year-old boy died, and then another child, and Welch, examining a sick girl's throat, saw the grey membrane he had been dreading. It was diphtheria: a bacterial disease, wildly contagious, that chokes its victims — and it kills children first.

Welch had antitoxin serum on his shelves, but it had expired; the fresh supply he had ordered had not arrived before the sea froze. Without serum, his own estimate was catastrophic: the disease could sweep through Nome and the surrounding Native villages and kill thousands. On 22 January 1925 he sent a radio telegram that stopped the country in its tracks: an epidemic of diphtheria was almost inevitable, and he needed a million units of serum — immediately. The town was quarantined, the newspapers seized the story, and across America people asked the same question: how do you get medicine to a place that nothing can reach?

Serum was found — 300,000 units in a hospital in Anchorage. The railway could carry it as far as Nenana, but that still left 674 miles of frozen wilderness. The serum was usable for days, not weeks, and the normal mail run took twenty-five. The governor made his decision: a relay of the best dog-sled drivers in the territory, running day and night, each covering one leg of the trail and handing the serum on like a baton. Twenty drivers and around a hundred and fifty dogs took their positions along the route.

They ran into one of the worst cold snaps in memory. "Wild Bill" Shannon took the first leg out of Nenana at night, in temperatures around fifty below zero; he arrived with his face blackened by frostbite, and several of his dogs did not survive the run. Others drove through winds so violent that they flipped sleds and through whiteouts so total that the drivers could not see the lead dog — they navigated from memory, trusting the animals to hold the trail. The whole country tracked their progress; the serum, warmed at each roadhouse, moved up the trail hour by hour.

The longest and most perilous leg belonged to Leonhard Seppala, the territory's champion driver, and his lead dog Togo — twelve years old, small, and famously intelligent. To save a day, Seppala took the shortcut no one else would risk: straight across the frozen surface of Norton Sound, at night, in a gale, on sea ice that could crack and drift out into open water with the wind. Togo held the line through the darkness and brought the team across. Counting the outward run to meet the serum, Seppala's team covered some 260 miles — more than four times the distance of any other driver — and crossed the deadliest ice in Alaska twice.

The final leg fell to Gunnar Kaasen and a lead dog named Balto. They drove into a blizzard so ferocious that Kaasen at times could not see the dogs in front of him; at one point a gust flipped the sled, and the serum cylinder vanished into a snowdrift. Kaasen tore off his gloves and dug through the snow bare-handed until his fingers found it. At half past five in the morning on 2 February 1925, his team limped down Front Street in Nome and he handed Dr Welch the serum — frozen solid, but intact and, once thawed, still good. The relay had covered 674 miles in five and a half days, through the worst weather in twenty years. The quarantine held, the serum worked, and the epidemic was stopped; the official death toll stayed in single figures, though the true number among the Native villages was likely higher.

Then came the strange afterlife of the story. Balto — the dog who happened to cross the finish line — became one of the most famous animals on Earth: newsreels, a national tour, and, before the year was out, a bronze statue in New York's Central Park, engraved Endurance · Fidelity · Intelligence. Togo — older, smaller, and responsible for the longest and deadliest stretch of the entire run — got almost nothing. Seppala carried the injustice bitterly for the rest of his life: the papers, he felt, had crowned the wrong dog.

History has slowly been correcting itself. Today, mushers and historians generally regard Togo as the true athletic hero of the Serum Run, and he has his own statue, his own films, and a place of honour in the record. The run itself is commemorated by the Iditarod, the great annual sled race across Alaska. And the deeper legacy is medical: the drama of 1925 helped push governments to fund immunisation, and within a generation, diphtheria — the child-killer that had terrorised Nome — had almost vanished from the map.