Women in Hong Kong are facing months of delay in getting vaccinated against human papilloma virus, or HPV, because of a drug shortage, and authorities are receiving a flood of complaints. The virus is a major cause of cervical cancer.

Private clinics in the city have been canceling appointments and blocking new patients looking to get vaccinated, some since April.

The shortage has triggered a raft of complaints to the Hong Kong Department of Health and the Consumer Council, the city's consumer rights watchdog, mostly from mainland residents who have traveled to the city only to find they can no longer get an injection.