1/ The history of human experimentation is endlessly fascinating (& troubling).
I recently came across this 1932 study from Edvin Brusgaard demonstrating that the agent that causes herpes zoster (shingles) can infect people with varicella (chicken pox). https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2133.1932.tb09534.x

2/ Brusgaard, incidentally, may be best known for the Oslo Study of the Natural History of Untreated Syphilis, a precursor to the Tuskegee Study, which he inherited from Caesar Boeck. https://www.sciencedirect.com/science/article/abs/pii/0021968155901399

3/ In the zoster/varicella study, Bursgaard took blister fluid contents from patients with shingles and inoculated them under the skin of healthy young children to see if they could induce infection with varicella.

4/ Infection in the recipients, including generalized chicken pox, was common, confirming that the blister fluid contained infectious particles.

5/ Furthermore, the infection often spread from the experimentally infected children to "healthy children occupying the same ward."

6/ There is of course no mention of the ethics of what was done, or of parental permission (which would be problematic for young children in any case). And no description of who the kids who were chosen for the experiments were.

7/ More than anything, I am reminded that, although we should always look for ways to improve the ethics of human research, we are in an infinitely better place than we were not so very long ago. /fin

*and of course, I misspelled Bruusgaard's name multiple ways in this thread...