Next week marks 100 years since the conclusion of the Great Serum Run, also known as the Great Race of Mercy, to deliver life-saving medication to the Alaska Gold Rush town of Nome.The town was hundreds of miles from anywhere, cut off by the frozen sea and unrelenting blizzards, and under siege from a contagious disease known as the “strangling angel” for the way it suffocated children.A group of sled dogs and mushers raced for more than five days through hypothermia, frostbite, gale-force winds and blinding whiteouts to deliver life-saving serum and free the community from the grip of diphtheria.“People just dropped whatever they were doing," said Diana Haecker, a Nome Kennel Club board member and co-owner of Alaska’s oldest newspaper, the Nome Nugget. "These mushers got their teams ready and went, even though it was really cold and challenging conditions on the trail.”Jonathan Hayes, a musher from northern Maine who has been working to preserve the genetic line of sled dogs driven on the run by famed musher Leonhard Seppala, is currently recreating the trip. Hayes left Nenana on Monday with 16 Seppala Siberian sled dogs, registered descendants of Seppala's team.Hayes runs the Poland Spring Seppala Kennel, which works to continue the bloodlines of the canine heroes.While a husky mix named Balto may be the most famous member of the team as he was the leader of the team that completed the run, there were a total of 20 teams of sled dogs that covered the route.The lead dog that covered the most distance was 12-year-old Togo, who traveled 264 miles through blizzard conditions.Within two years of that renowned run, Togo was brought to Maine. His owner partnered with Poland Spring's Elizabeth Ricker to open a nearby Kennel and Togo spent the last four years of his life in Poland Spring.Today, a small museum inside Poland Spring's Maine State Building commemorates Togo's feat, as well as his later years living in Maine.In 2022, a new statue was dedicated at the resort to celebrate Togo.Other communities are also marking the anniversary of the serum run— including the village of Nenana, where the relay began, and Cleveland, Ohio, where Balto is stuffed and displayed at a museum.Diphtheria is an airborne disease that causes a thick, suffocating film to develop at the back of the throat; it was once a leading cause of death for children. The antitoxin used to treat it was developed in 1890, and a vaccine in 1923; it is now exceedingly rare in the U.S.Nome, western Alaska’s largest community, had about 1,400 residents a century ago. Its most recent supply ship had arrived the previous fall, before the Bering Sea froze, without any doses of the antitoxin. Those the local doctor, Curtis Welch, had were outdated, but he wasn't worried. He hadn’t seen a case of diphtheria in the 18 years he had practiced in the area.Within months, that changed. In a telegram, Welch pleaded with the U.S. Public Health Service to send serum: "An epidemic of diphtheria is almost inevitable here.”The first death was a 3-year-old boy on Jan. 20, 1925, followed the next day by a 7-year-old girl. By the end of the month, there were more than 20 confirmed cases. The city was placed under quarantine.West Coast hospitals had antitoxin doses, but it would take time to get them to Seattle and then onto a ship for Seward, an ice-free port south of Anchorage. In the meantime, enough for 30 people was found at an Anchorage hospital.It still had to get to Nome. Airplanes with open-air cockpits were ruled out as unsuited for the weather. There were no roads or trains that reached Nome.Instead, officials shipped the serum by rail to Nenana in interior Alaska, some 675 miles from Nome via the frozen Yukon River and mail trails.Thanks to Alaska’s new telegraph lines and the spread of radio, the nation followed along, captivated, as 20 mushers — many of them Alaska Natives — with more than 150 dogs relayed the serum to Nome. They battled deep snow, whiteouts so severe they couldn’t see the dogs in front of them, and life-threatening temperatures that plunged at times to minus 60 degrees Fahrenheit.The antitoxin was transported in glass vials covered with padded quilts. Not a single vial broke.Seppala, a Norwegian settler, left from Nome to meet the supply near the halfway point and begin the journey back. His team, led by his dog Togo, traveled more than 250 miles of the relay, including a treacherous stretch across frozen Norton Sound.After about 5 1/2 days, the serum reached its destination on Feb. 2, 1925. A banner front-page headline in the San Francisco Chronicle proclaimed: “Dogs victors over blizzard in battle to succor stricken Nome.”The official record listed five deaths and 29 illnesses. It’s likely the toll was higher; Alaska Natives were not accurately tracked.Seppala and Togo missed the limelight that went to his assistant, Gunnar Kaasen, who drove the dog team led by Balto into Nome. Balto was another of Seppala’s dogs, but was used to only haul freight after he was deemed too slow to be on a competitive team.Balto was immortalized in movies and with statues in New York's Central Park and one in Anchorage intended as a tribute to all sled dogs. He received a bone-shaped key to the city of Los Angeles, where legendary movie actress Mary Pickford placed a wreath around his neck.But he and several team members were eventually sold and kept in squalid conditions at a dime museum in Los Angeles. After learning of their plight, an Ohio businessman spearheaded an effort to raise money to bring them to Cleveland. After dying in 1933, Balto was mounted and placed on display at the Cleveland Museum of Natural History.