Japan is experiencing an ongoing shortage of generic medicines due to a string of scandals and other structural problems, hindering efforts to combat the flu.

Out of over 16,000 pharmaceutical products, 3,103 — or 18.5% — were either in limited or suspended supply as of the end of October, according to a survey conducted by the Federation of Pharmaceutical Manufacturers’ Associations of Japan.

Over 60% of these are generic drugs, which include treatments for fever, cough and other flu-like symptoms. With the health ministry declaring the start of this year’s flu season on Nov. 8, demand for such medicine is rising.