An increasing number of Chinese female patients are visiting Korean obstetrics and gynecology clinic to receive Gardasil 9, a nine-valent human papillomavirus (HPV) vaccine developed by Merck.

The vaccine prevents 90 percent of HPV infection, which is the leading cause of cervical cancer, and requires patients to receive three doses for inoculation. In Korea, the vaccine costs around 200,000 won ($168) per injection.

Chinese patients started to visit Korea after Merck began marketing the vaccine in the country from April last year. The vaccine was so popular that in some Chinese cities there were more than 20,000 vaccination reservations per second, which in turn led to a shortage of the vaccine. Even after the vaccine’s price rose, patients wanting to get vaccinated did not decrease in number. Soon, the fake versions of the vaccine started to appear.

That has led to more and more Chinese patients visiting Korea to receive the vaccine with some obstetrics and gynecology clinics are saying that they are treating 30 to 40 Chinese patients daily.

“The Chinese visitors told us that they were afraid of receiving the vaccine back home, while some were skeptical of taking any drugs in China altogether,” a local obstetrics and gynecology clinic was quoted as saying by Chosun Ilbo, a vernacular newspaper.