Washington, May 16 (IANS): The US' union of registered nurses condemned the Centers for Disease Control and Prevention (CDC) for lifting mask recommendations for vaccinated people in the country, stating that it would jeopardise the health of frontline workers, the media reported.

The CDC recommendation "is not based on science" and it would jeopardise the health of frontline workers and the general public, Bonnie Castillo, a registered nurse and executive director of the union, National Nurses United, was quoted as saying by the New York Times on Saturday.

"This is a huge blow to our efforts at confronting this virus and the pandemic," said Castillo, adding that there still remain people who have not yet been vaccinated.

"The mask is another lifesaving layer of protection for workers."

Since Covid vaccine distribution began in the US on December 14, 2020, more than 268 million doses have been administered.

Over 120 million people have been fully vaccinated.

The CDC, while introducing the new recommendations, also cited two recent scientific findings: few vaccinated people become infected with the virus, and the transmission seems rarer still, and the vaccines appear to be effective against all known variants of the coronavirus.

However, the union noted that more than 35,000 new cases of coronavirus are being reported and over 600 people are dying each day, the report said.

"Now is not the time to relax protective measures, and we are outraged that the CDC has done just that while we are still in the midst of the deadliest pandemic in a century," Castillo said.

Businesses large and small are also grappling with how to adapt to the CDC's surprise guidance.

Some of the nation's largest retailers said that they have no immediate plans to change their policies and would continue requiring both customers and workers to wear masks on the premises, according to local media reports.

Other businesses said they are re-evaluating their protocols.

Walt Disney World located in Orlando, Florida announced on Friday that masks and face coverings for guests would be "optional in outdoor common areas" at the resort starting on Saturday.

Grocery chain Trader Joe's became the first prominent US retailer on Friday to drop its mask policies for vaccinated shoppers.

It was followed by Walmart, the country's No. 1 retailer with more than 4,700 stores, which said in a memo to employees that vaccinated customers can shop without masks.

At a White House briefing on May 13, CDC Director Rochelle Walensky: "Anyone who is fully vaccinated can participate in indoor and outdoor activities, large or small, without wearing a mask or physical distancing."