Staff members of Macao Health Bureau check the temperature data of the truck at the handover ceremony of the second batch of mainland-made COVID-19 vaccines in Macao, south China, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]

Macao Health Bureau Director Lei Chin Ion (C) signs receiving documents at the handover ceremony of the second batch of mainland-made COVID-19 vaccines in Macao, south China, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]

Guests pose for a group photo at a handover ceremony of the second batch of mainland-made COVID-19 vaccines in Macao, south China, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]

The truck carrying the second batch of mainland-made COVID-19 vaccines arrives at the Zhuhai-Macao Cross-Border Industrial Zone, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]

Staff members transport the second batch of mainland-made COVID-19 vaccines in Macao, south China, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]

Staff members transport the second batch of mainland-made COVID-19 vaccines in Macao, south China, Feb. 28, 2021. The second batch of mainland-made COVID-19 vaccines were delivered to the Macao Special Administrative Region on Sunday. The first batch of mainland-made vaccines were delivered to Macao on Feb. 6. Inoculation started on Feb. 9. [Photo/Xinhua]