Jakarta has attained “herd immunity” weeks after the Delta version of the coronavirus ravaged the Indonesian capital, according to the city’s deputy governor, ahead of the president’s expected decision on Monday on whether to prolong COVID-19 restrictions.

The outbreak wreaked havoc on Jakarta for most of last month, with overcrowded hospitals, oxygen shortages, and COVID-19 patients dying at home, but case counts have decreased significantly in recent weeks, while vaccination rates have risen.

On July 12, more than 14,600 illnesses were reported in Jakarta, but by Sunday, the number had dropped to 700.

“Jakarta has entered the green zone and has reached herd immunity,” deputy Jakarta governor Ahmad Rizia Patria told reporters on Sunday.

The deputy governor was referring to high vaccination rates in the capital, where more than 54% of residents are fully vaccinated and most have received one shot.

Nationally, just over 11% of the population have been fully vaccinated since the Southeast Asian nation began its inoculation program this January.

Pandu Riono, an epidemiologist at the University of Indonesia said the deputy governor had misunderstood the concept of herd immunity.

“Even if we reach 100% vaccine coverage, the immunity level is still below 80%,” he said, adding that vaccine efficacy levels were only about 55%.

Home to more than 10 million people, Jakarta has predominately administered China’s Sinovac vaccine, while some residents have received Astra Zeneca and Sinopharm shots.

President Joko Widodo is expected to announce on Monday whether current social restrictions that have been in place since July in Java and Bali will be relaxed or extended.

The government has in recent weeks maintained social curbs but permitted limited capacity at malls and restaurants.

Despite an overall decline in cases nationally, Indonesia still recorded more than 12,000 cases on Sunday, as it continues to battle one of Asia’s worst coronavirus outbreaks.

Since mid-July the country has also recorded more than than 1,000 deaths from COVID-19 each day, one of the highest rates globally.

While cases have declined in Jakarta and some parts of Java, the highly contagious Delta continues to surge in other islands, including in parts of Sumatra, Kalimantan, Sulawesi and remote Papua.