"Driftwood" (1947) with Natalie Wood and Walter Brennan

Here's a gem of a film which has great application to the ongoing debate about vaccinations. In this case the disease is Rocky Mountain Spotted Fever, which is spread by tics. Until the 1920's the disease killed about 10% of those infected. After the vaccine was discovered that rate was pretty much cut in half. With the advent of anti biotics  the vaccine is no longer necessary, and is treated with Doyxcelin, or other forms of the Tetracycline family. If caught in time the rate of mortality is the same as using the vaccine. 

This is a fictional story, but it carries quite a wallop. Natalie Wood plays a little girl who lives with her Great Grandfather, played by H.B. Warner, a preacher who lives a long way from any town. When he dies she travels by foot to the nearest town all alone. Halfway there she witnesses a plane crash. Alone in the woods, surrounded by coyotes and mountain lions, she encounters a seemingly stray dog, who is burned. They quickly become close and continue on the journey together.

While sleeping by the side of the road she is found by a doctor from the town where she is headed. Doctor Steve, played by Dean Jagger, takes her to the town and the Sheriff, whom her Great Grandfather always told her to see if/when he should pass away.

Doctor Steve, who has been working with tics in order to find a cure for Spotted Fever, is about to leave for San Francisco where he hopes to find work conducting research for a cure. The town he comes from doesn't even have a hospital. And the people there are not interested in trying the vaccine he has not yet perfected. That all changes when one of the children in the town dies from the disease.

The little girl has a secret. The dog, whom she calls Hollingsworth, actually comes from the plane she watched crash. And that dog is immune to the Fever. For how all this plays out you will have to watch the film. Beautifully written, acted and directed, this film, which also stars Walter Brennan and even Margaret Hamilton as the lovable town spinster, will capture your heart.