The Department 19 Files: Undead in the Eternal City: 1918

A short story from the world of Department 19. In 1891, Abraham Van Helsing and a group of friends faced Dracula, the world's first vampire - and won. The survivors of that battle founded Department 19, and have been secretly saving the world ever since. A highly classified archive exists recording every act of bravery in that time. That archive is now open. These are the Department 19 files. Rome, 1918. The Great War is over, but the world is in the grip of a Spanish Influenza pandemic, and people are dying in their millions.
Quincey Harker and his Special Reconnaissance Squad recuperating in Rome, trying their hardest to drink away their memories. But they are not the only visitors to the Eternal City: Valeri Rusmanov, the oldest and most powerful vampire on earth, and his wife are roaming the dark streets on a ghastly holiday, delighting in the death that surrounds them, soaking in the sounds of the sick, feasting on innocent blood.
and about to cross paths with Quincey and his men.