Dr Avinash Supe, chairman of the COVID-19 death audit committee, said it was too early to talk about herd immunity.
The data collected by the Brihanmumbai Municipal Corporation indicates the changing trend of Mumbai's new coronavirus cases which are now emerging from the suburban areas as opposed to Southern parts.
A total of 516 patients were discharged from the hospitals in the past 24 hours, taking the number of recoveries to 24,209, the statement said.
Meanwhile, Maharashtra CM Uddhav Thackeray urged the central government to restart the Mumbai suburban train services for the people who are involved in the essential services.
Movement of stranded labourers, migrant workers, pilgrims, tourists will continue to be regulated as per the standard operating procedures.
Uddhav Thackeray said BMC had arranged for intensive care units and isolation beds at several places in the metropolis.
In a release, the civic body said the toll in the city rose to 882 with 41 more patients dying due to the infection.
Coronavirus also claimed the lives of 38 people on Sunday, which took the death toll in the country's financial capital to 734, the official said.
The patient was found to have hanged himself with his pajamas from a steel rod on the ninth-floor terrace of the hospital on Saturday afternoon, a police official said.
It took nearly 56 days for the COVID-19 cases to cross the 10,000-mark, after the country's financial capital reported its first case on March 11 and 49 days to cross the 400 deaths.
Out of 10 lakh applicants, only 53,000 people have got permission in the last 40 days to travel from one part state to another.
A total of 406 new suspected cases were admitted in various hospitals in the city.
"Out of the 18 deaths, 10 patients had co-morbidities, while three others had age-related factors," the BMC claimed.
Now there are only five coronavirus hotspots ― Mumbai city, Mumbai Metropolitan Region, Pune, Nagpur, and Malegaon.
The 146 persons will undergo medical checkup and a separate building has been readied if they need to be quarantined.