This was met with confidence from Governor Anies Baswedan, who expected millions of Jakartans to receive the vaccines by mid-August. But health experts are skeptical, saying it is an "unrealistic" target.

In his instruction on Monday, the President said he wanted Jakarta to vaccinate 100,000 people a day starting next week.

"It's an ambitious target but we have no other options but to do it," Jokowi said after attending a mass vaccination event in North Jakarta, along with Anies and Health Minister Budi Gunadi Sadikin.

Herd immunity occurs when a large portion of a population becomes immune to an infectious disease, making the spread of disease from person to person unlikely. Experts estimate that at least 70 percent of the population should be inoculated to reach herd immunity against the coronavirus.

Jokowi said Jakarta had a very high level of mobility and social interactions so the speed of vaccine rollout would "determine how fast COVID-19 will spread" in the city.

Jakarta has seen an alarming resurgence of coronavirus cases in the past weeks, with officials and experts saying that the capital is now in a “critical phase” and could see a higher spike than the last wave of infections in January.