Shenzhen authorities started a new lottery system for 9-valent human papilloma virus vaccine reservations on Monday due to a severe shortage.

The vaccine, supplied by US-based pharmaceutical company Merck & Co Inc, helps protect girls and women ages 9 to 26 against diseases like cervical cancer caused by nine types of HPV.

It has been highly sought after since August, when it was introduced to Shenzhen following 2-and 4-valent vaccines. Until then, women were swarming to neighboring city Hong Kong for doses.

But the three shots cost 7,000 to 10,000 yuan in Hong Kong, and less than 4,000 in Shenzhen.

The city's health authority opened online reservations in September and the website received over 3 million daily page views, with the number jumping to 9 million in October.

However, the supply was only 600 to 1,000 doses every month throughout the southern city of Guangdong.

The large gap between demand and supply resulted in people scrambling for online reservations, even drawing the attention of scalpers. This made a lottery system necessary.

The quota of the first round of vaccine lottery is 1,305 reservations and each reservation is guaranteed to get all three shots. The quota of lotteries for the following months is still uncertain.