-- "The Mediocre Presidents," a song on The Simpsons
But apparently it wasn't just a virus that did in the 9th President of the United States, William Henry Harrison. It's conceivable that he might have recovered from his illness had he been able to rest properly, which was the only really effective medicine available for his condition in the 1840s. The president didn't get the rest he needed, however.
"General Harrison was ... smothered by the most shameless swarm of fortune hunters the capital had seen since the coming of another Hero twelve years before [Jackson, 1829], wrote famed biographer Marquis James in Andrew Jackson: Portrait of a President (1937). "They filled every room [of the lower level of the White House] and defied eviction. The President opened a door, expecting to meet his Cabinet. The spoilsmen crushed about him. Soon the Executive's pockets were filled with their petitions, then his hat, then his arms; and thus he staggered upstairs to revive himself with 'stimulants.' "
As President Harrison's condition worsened, the best that medicine could offer was employed to restore him to health: "Blistering of the skin was a standard method to draw evil humors from the body," noted Edward B. MacMahon and Leonard Curry in Medical Cover-Ups in the White House (1987). "Given that the president was sick with pneumonia, the President's physicians tried blistering the right side of his chest. The President did not improve.
"Next, the doctors applied suction cups to the blistered skin to draw out the evil, elusive substance that weakened him. Then the doctors gave him ipecac to induce vomiting. They also gave him calomel and castor oil to purge his bowels. Then they administered sedative to the fast-weakening President in the form of opium and brandy. As a last resort, they tried Virginia snakeweed, a Seneca Indian remedy. Nothing worked."
William Henry Harrison died at early in the morning of April 4, 1841, a month after assuming office. He might not have done much as president, but his presidential fame was thus assured anyway.