The kid hadn't been exposed. He had no immunity.
5 seconds sound clip from the Suddenly (1954) movie soundboard.
You can hear this line at 00:14:56 in the Blu-ray version of the movie.
Quote context
[...]
- Ellen, you're a grown-up girl.
- You got a problem you haven't worked out. That's no reason why Pidge should have your problem.
- I've only done what I thought was right, dad.
- What does that have to do with Pidge?
- The kid hadn't been exposed. He had no immunity.
- There's cruelty and hatred and tyranny in the world. You can't make believe they aren't there.
- And Pidge has got to learn what is the law and what isn't the law, so's he can defend it.
- Defend it? So he can become a soldier and go out and be murdered, like his father was?
- My son was killed in the performance of his duty, Ellen.
[...]