(CNN Philippines) Metro Manila – Health experts in the country agree that the implementation of granular lockdowns in Metro Manila starting Sept. 8 would not be enough to significantly decrease COVID-19 cases in the region.

OCTA Research fellow Dr. Guido David said granular lockdowns must be complemented by other interventions, such as randomized mass testing, more aggressive contact tracing, and early detection and isolation efforts to effectively curb the spread of the virus.

David added that based from experience, granular lockdowns alone are not effective if the virus expanded its reach in an area.

“Our local governments will have a hard time in this setup because of their limited manpower. For example, there are 100 barangays in a city and 10 of them only have cases, it will be easier to implement a granular lockdown. But if there are 90 barangays with cases, the local government will have a hard time dealing with those because there will be persons assigned to man the locked down area and bring food there,” Guido told CNN Philippines’ Newsroom Weekend on Sunday.

Infectious disease specialist Dr. Benjamin Co said the granular lockdowns should not only last for two weeks, the timeframe imposed by the Inter-Agency Task Force in implementing the localized quarantine classification.

“It takes one family of five or six people in the household at least three to four weeks to be fully recovered. If you have one whole street, one whole barangay that’s infected, it will take them two to three months to recover,” Co told CNN Philippines.