A health worker pretends to inject the COVID-19 vaccine to a woman during a mock drill for COVID-19 vaccination at a vaccination centre in New Delhi, India, Jan. 2, 2021. (Xinhua/Partha Sarkar)

Health professionals from Bruhat Bengaluru Mahanagara Palike (BBMP) take part in a mock drill for COVID-19 vaccination at a health centre in Bangalore, India, Jan. 2, 2021. (Str/Xinhua)

A health worker pretends to inject the COVID-19 vaccine to a man during a mock drill for COVID-19 vaccination at a vaccination centre in Hyderabad, India, Jan. 2, 2021. (Str/Xinhua)

A health professional from Bruhat Bengaluru Mahanagara Palike (BBMP) checks a cold storage for vaccine during a mock drill for COVID-19 vaccination at a health centre in Bangalore, India, Jan. 2, 2021. (Str/Xinhua)

A health worker pretends to inject the COVID-19 vaccine to a woman during a mock drill for COVID-19 vaccination at a hospital in Agartala, the capital city of India's northeastern state of Tripura, Jan. 2, 2021. (Str/Xinhua)