"There’s a long history linking zinc with optimal immune function. For example, it’s known that people whose zinc levels are too low have little to no infection-fighting T cells and the thymus, the organ in which T cells develop, is nearly non-existent, Iovino said. When zinc-deficient people are given extra zinc, their thymuses grow and start pumping out these immune cells."
https://www.fredhutch.org/en/news/center-news/2022/03/dudako...
"There’s a long history linking zinc with optimal immune function. For example, it’s known that people whose zinc levels are too low have little to no infection-fighting T cells and the thymus, the organ in which T cells develop, is nearly non-existent, Iovino said. When zinc-deficient people are given extra zinc, their thymuses grow and start pumping out these immune cells."