I saw the previous comment about obtaining hair follicles from a donor (another person than yourself) transplanted to the patient. I’ve looked on the internet and did a search for “immunoprivileged follicle” and found dozens of articles that suggest that the follicle of the hair seems to fall in the category.

They’d even claim that it is also trans-gender: www.nature.com/nature/journal/v402/n6757/full/402033a0.html
and the Journal of Investigative Dermatology Symposium: www.nature.com/jidsp/journal/v8/n2/full/5640115a.html

Does this mean that it is possible,after all, to obtain hair follicles from a donor? Thanks!

It may be possible, but for all practicality, not probable. Even with the best case scenario, where would you get the donor hair? Could this give a new meaning to selling your hair for money?

Generally hair transplantation from one person to another carries the same risk as organ (liver, heart, kidney) transplants. There is a risk of rejection and failure and life long anti-rejection medication. You may accept the risk of rejection when faced with threatening situations such as heart/ liver/ kidney failure, but most people spending thousands of dollars for a cosmetic (hair transplant) procedure may not accept the failure risk. One might think that hair from a newborn baby might be immunoprivileged (it seems to work for a heart transplant), but again, who would endorse such a donor?