Once again, as another wave of COVID-19 wave looks poised to raise cases across Philadelphia, city leaders are reimplementing an indoor mask mandate in hopes of curbing the uptick.

According to the latest city data, Philly averaged 142 cases a day as of April 8. That’s up 50% from the previous daily count of 89 from March 29.

The reimplementation is also in line with a new safety protocol system put in place by the city in February that accounts for cases, hospitalizations, and infection rates to determine what measures to put in place. 

After being level one, all clear since March 2, when the city dropped its previous indoor mask mandate, Philly now becomes the first major U.S. city to put one back in place as it rises to level two in its grading system. The city’s level two protocol happens if there are less than 225 daily cases, hospitalizations are under 100, but cases have increased more than 50% between a 10-day timespan.

An indoor mask mandate is implemented, but there is still no requirement for vaccines or a negative COVID test to eat or dine indoors.

The current wave of COVID-19 to hit Philly is the one brought on by what is officially being called the omicron B.A. 2 subvariant. It is a new mutation of the original omicron variant that is also 30% more contagious. However, the variant does not appear to cause a more serious disease.

Omicron B.A. 2 is the dominant variant in 68 countries, including the U.S. As many experts and outlets have also noted, the rise of the variant is also coming as many places around the country are beginning to reopen and people are foregoing masks.

The variant has already made waves in Europe, and put China through its worst COVID period since the initial outbreak of coronavirus in early 2020. The latter is also causing one of the world’s biggest economies to reel for the moment, as society shuts down in parts of the country.

Predictions for the impact of omicron B.A. 2 in the U.S. are still to be determined, but health officials in places like Philadelphia are taking no chances.

“If we fail to act now, knowing that every previous wave of infections has been followed by a wave of hospitalizations and a wave of deaths, it’ll be too late for many of our residents,” said Philly Health Commissioner Dr. Cheryl Bettigole.

For weeks, leaders like her had been encouraging mask-wearing indoors, but now it will be the official mandate in Philly again.

The city is giving businesses a week to adjust, with April 18 as the official start date of the new mandate.