New mask mandates and rules cascaded Tuesday and Wednesday following Centers for Disease Control and Prevention (CDC) guidance that vaccinated people in high-transmission areas should still wear masks indoors, bringing back pandemic health restrictions for many Americans. 

"I have stuck with CDC guidance throughout the pandemic and today is no different," Kansas City, Mo., Mayor Quinton Lucas tweeted Tuesday night. "I will return Kansas City to a mask mandate indoors based upon national and regional health guidance and discussion with other Kansas City leaders."

He added: "We cannot ignore the rapid spread of the COVID-19 Delta variant in Missouri—outpacing much of the country. We will do all we can to ensure our corner of this state is safe."

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With the rapid spread of the delta variant of the COVID-19 virus, some cities and counties, led by Los Angeles, brought back mask mandates in recent weeks. Some were also calling for the CDC to bring back its universal mask-wearing recommendation nationally. 

The agency itself does not have the power to implement or enforce mandates. And some states and local officials – including New York City Mayor Bill de Blasio – seemed reluctant to follow the CDC's new guidelines after they were announced. 

But many local and state governments follow its advice closely on the coronavirus, and it took mere hours for some jurisdictions to bring back their mandates. 

Nevada was one of those. It took just over three hours after the CDC's new guidance for the state to issue a new mask mandate for 12 of its 17 counties. 

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"Nevadans & visitors - please see the latest update below. Let’s mask up to keep one another safe," Gov. Steve Sisolak tweeted. 

Yolo County, Calif., also implemented a new mask mandate that will go into effect Friday, according to FOX 40

So did the House of Representatives and the White House, each taking action late Tuesday. 

Even at least one university, Duke, reacted to the CDC guidance Wednesday by issuing a mask mandate for all people indoors, "regardless of vaccination status."

And many other areas, even if they did not fully implement new mandates in the immediate aftermath of the CDC announcement, adjusted their rules and guidance in what could potentially be precursors to reinstated mandates. 

Oregon quickly changed its guidelines Tuesday after the CDC update: "[T]he Oregon Health Authority today is recommending universal mask use in public indoor settings throughout the state to protect Oregonians from COVID-19."

"Let's mask up to protect our friends, family members, and neighbors from COVID-19," Oregon Gov. Kate Brown tweeted.

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Boise, Idaho, issued a mask mandate inside its city buildings, citing low vaccination rates. The city's press release said it is working with "state and local health officials to quickly change or modify orders as needed," potentially foreshadowing even broader mask rules. 

Alexandria, Virginia, issued a press release Tuesday saying "masks should be worn in public indoor settings" no matter a person's vaccination status. Such recommendations, like one in Los Angeles, have at times turned into full mandates in recent weeks. 

There is still significant pushback against universal masking, and not all jurisdictions are following the CDC's suit. The St. Louis County Council voted to end its recently implemented mask mandate Tuesday night, according to FOX 2. County Executive Sam Page, however, says the mandate is still in effect despite the vote. And the St. Louis city mask mandate, FOX 2 reported, is still in effect. 

Even some Democratic governors who are known for their aggressive coronavirus mitigation measures are now slow to follow the CDC with universal masking. 

"People have the ability, each individual to make the decision to get a vaccine," Pennsylvania Gov. Tom Wolf said Tuesday. "If they do, that’s the protection."

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Wolf's comments came just before the CDC officially announced the changed guidelines. But it was widely anticipated that the changes were coming early Tuesday when he made the comments on KDKA-AM in Pittsburgh. 

Michigan Gov. Gretchen Whitmer, according to FOX 2, said Tuesday that she does "not anticipate another pandemic order, not in the near future and maybe not ever." She said vaccines are the best way to fight the pandemic.

We got this less than 24 hours ago, we really want to make sure we look at all the issues… Our number one focus by far is on vaccination.

— New York City Mayor Bill de Blasio, asked about new CDC indoor masking guidance for vaccinated people

And big-state neighbors Gov. Andrew Cuomo and Gov. Phil Murphy – of New York and New Jersey, respectively – each said they are reviewing the guidance but did not take any immediate action, according to FOX 5. Cuomo, meanwhile, emphasized the importance of vaccines Wednesday by mandating them for state workers.

De Blasio – who mandated vaccines for city workers this week – declined Wednesday to commit to mandating masks indoors, saying New York will "assess the research behind" the CDC recommendation.  

"We got this less than 24 hours ago, we really want to make sure we look at all the issues," de Blasio continued at a press conference. "Our number one focus by far is on vaccination." Multiple de Blasio health officials also seemed reluctant to again mandate masks, highlighting that the CDC has not yet provided the scientific justification for its new guidelines.  

Besides the blue states that are reluctant to bring back mandates, many red states are openly hostile to the idea. Govs. Ron DeSantis of Florida and Pete Ricketts of Nebraska are just two of the GOP governors who said they have not plans to follow the new CDC guidance. 

CDC Director Rochelle Walensky explained that the reason for the CDC's reversal on indoor masking for vaccinated people is because "in rare occasions, some vaccinated people infected with the delta variant after vaccination may be contagious and pass the virus to others."

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The move comes despite the fact that COVID-19 vaccines are extremely effective at preventing severe illness, hospitalization and death. The vaccines also massively reduce the risk of virus transmission – Walensky herself said that even transmission of the highly contagious delta variant from vaccinated people is "rare." 

Many people, especially GOP elected officials, are panning the CDC for its new guidance, which they say is misguided. 

"COVID-19 vaccines are safe, effective and FREE, and I continue to encourage all Montanans to get vaccinated to help put this pandemic behind us for good," Sen. Steve Daines, R-Mont., said. "I do not support mask mandates and believe the CDC's new guidance will undermine confidence in vaccines." 

The Associated Press contributed to this report.