The city of Nanjing has been optimizing the process of vaccination to provide more convenient services to citizens, with mobile vaccination vehicles dispatched to residential neighborhoods and business centers. (Photos: Xinhua)

Mobile vaccination vehicles are parked near a business center in Nanjing, east China's Jiangsu Province, April 30, 2022.

A woman gets a vaccination against COVID-19 aboard a mobile vaccination vehicle near a business center in Nanjing, east China's Jiangsu Province, April 30, 2022.

A resident gets on a mobile vaccination vehicle for observation after the COVID-19 vaccination near a residential neighborhood in Nanjing, east China's Jiangsu Province, April 29, 2022.

A mobile vaccination vehicle is parked near a residential neighborhood in Nanjing, east China's Jiangsu Province, April 30, 2022.

A man gets a vaccination against COVID-19 aboard a mobile vaccination vehicle near a business center in Nanjing, east China's Jiangsu Province, April 30, 2022.

A senior resident registers for COVID-19 vaccination aboard a mobile vaccination vehicle near a residential neighborhood in Nanjing, east China's Jiangsu Province, April 29, 2022.

Mobile vaccination vehicles are parked near a residential neighborhood in Nanjing, east China's Jiangsu Province, April 29, 2022.

Residents are under observation after the COVID-19 vaccination aboard a mobile vaccination vehicle near a residential neighborhood in Nanjing, east China's Jiangsu Province, April 29, 2022.