The BBB is a part of capillary walls and so there really isn’t a good way to “manually” inject beyond it. That said, there are current trials ongoing to temporarily disrupt the BBB using high intensity focused ultrasound, allowing injected chemotherapy to cross and help treat brain cancer.
I can imagine that would cause brain damage. It's not like an anti-anything targets one thing and only that
This is terrifying and I genuinely hope they cure this for all of humanity’s sake.