Evelyn Keyes in "The Killer That Stalked New York" (1950) - feat. Dorothy Malone & Jim Backus

Sheila Bennet arrives in New York after a trip to Cuba, smuggling $50,000 worth of diamonds. Realizing she is being followed, she mails the diamonds to her husband Matt and tries to evade a Treasury agent. While at a clinic, she inadvertently infects a little girl with smallpox, which is misdiagnosed as a cold. Matt is cheating on Sheila with her sister Francie, and when the diamonds arrive, the fence cannot buy them because police are searching. Matt is forced to stay in New York, and after Francie commits suicide over his betrayal, Sheila seeks revenge. As smallpox cases rise, city officials launch a mass vaccination campaign that quickly runs out of serum, causing panic. Agents discover that the disease carrier and the diamond smuggler are the same person. Sheila continues to evade capture, eventually confronting Matt, who falls to his death. She turns herself in, providing authorities with information before succumbing to the disease.