HONG KONG—As countries around the world fight to secure Covid-19 vaccines, Hong Kong has an abundant supply available to all adults over 30 and offers a choice between Western and Chinese-made doses.

Yet, many in Hong Kong aren’t in a rush to get immunized, and the city’s vaccination centers are running below capacity.

The city has received batches of the 22.5 million doses it has ordered—three times that of the population—yet so far around 6.01% of residents have received their first shots, lagging behind rival financial hub Singapore’s 16.12%, according to Oxford University tracker Our World in Data numbers from March 29.