https://ghostintheshell.fandom.com/wiki/Cyberbrain_Sclerosis

The Murai Vaccine, which was developed by Dr. Murai Chitose, is an undeniable and highly effective treatment for cyberbrain sclerosis, though the mechanism by which it worked was never identified. However, medical experts at the time consisted largely of MicroMachine treatment advocates. The vaccine treatment developed by Dr. Murai was conceptually behind the times, and the majority felt that allowing his research would delay completion of the concurrent research on MicroMachine treatment, which held great promise as a highly versatile technology despite its early stages of development. Certain company and government officials believed that if the vaccine was released, it would hinder the development of MicroMachine technology. Perhaps because of such concerns, approval of the Murai vaccine was delayed. Dr. Murai, who hoped for the approval of his vaccine treatment until the very end, died an unfulfilled death in February 2021 at age 68, without witnessing the decision of the drug evaluation committee. However, in April 2021, the Murai Vaccine was suddenly approved for special use by select individuals, after initially being rejected. This approval was not made public, and patients who used the vaccine do not officially exist.