Many cities relaxed their rules in recent weeks due to the decreasing number in cases, reversing course after cases exploded in the winter due to the Omicron variant.

But people in Chicago, Los Angeles, New Orleans, New York, San Francisco and Seattle are still required to show they are vaccinated before going out to some places, including restaurants and gyms. Since the vaccines became widely available, municipal leaders used the requirements to limit the virus’ spread but received backlash from some residents over the policy.

Seattle’s requirement is set to expire at the end of February, though businesses will still be able to implement their own proof-of-vaccination rules, the city announced in a statement earlier in February.

“The intent was to reduce COVID-19 transmission in high-risk indoor settings and thereby reduce the burden on our hospitals, while providing time for more people to get fully vaccinated,” wrote Washington’s King County Health Officer Dr. Jeff Duchin. “Following the record-breaking Omicron surge, we have seen a steady reduction in COVID-19 cases and hospitalizations, and hospital capacity is improving.”

Meanwhile, Chicago Mayor Lori Lightfoot announced Tuesday that the city would end its mask and vaccine requirements at the end of the the month.

“Folks, thanks to the ongoing progress we’re making coming out of the #Omicron surge, we’ll remove the mask mandate and vax requirement for certain public locations on February 28,” she tweeted. “This decision is in alignment with the State’s plans to lift the statewide indoor mask mandate on the same day.”

New Orleans’ vaccine requirement is set to remain in place through the city’s Mardi Gras celebration, NOLA.com reported.

Several large cities have recently ended their requirements, citing the drop in cases. On Friday, Boston Mayor Michelle Wu announced that the city would lift its proof-of-vaccination requirements, effective immediately.

“The public health data shows that we’re ready to take this step in our recovery,” Wu said in a statement. “This news highlights how much progress we’ve made in our fight against COVID-19 thanks to vaccines and boosters—which have always been our most effective weapon against the pandemic.”

Washington, D.C., Mayor Muriel Bowser also announced in February that the proof-of-vaccination policy would no longer be enforced—but the decision received some pushback from members of the city council. Council Member Brainne Nadeau wrote on Twitter: “Why would we give up on vaccines when we have come this far? Why are we not protecting the workers in these industries?”

Other major cities to rescind their proof-of-vaccination policies include Philadelphia, and Minneapolis and St. Paul, Minnesota. Many other major U.S. cities never required business patrons to show proof of vaccination.

Cases have dropped significantly since the peak caused by the Omicron variant earlier in the winter. On Friday, the United States saw an average of 103,462 new cases per day, down from 759,605 one month earlier, according to data from the Centers for Disease Control and Prevention.

Updated 02/22/2022 3:18 p.m. ET: This story has been updated with Lightfoot’s announcement that Chicago is dropping proof-of-vaccine requirements at the end of February.