Correct spelling for the English word "invaccination" is [ɪnvˌaksɪnˈe͡ɪʃən], [ɪnvˌaksɪnˈeɪʃən], [ɪ_n_v_ˌa_k_s_ɪ_n_ˈeɪ_ʃ_ə_n] (IPA phonetic alphabet).
Accidental inoculation of some disease, such as syphilis, during vaccination.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.