By Adam Harrington, Marissa Parra

CHICAGO (CBS Chicago/CBS News) — Mayor Lori Lightfoot and Chicago Department of Health Director Dr. Allison Arwady said Sunday that it is important now for everyone to wear a mask – vaccinated or not – amid rising COVID-19 rates driven by the especially contagious Delta variant, but also emphasized that it is unvaccinated people, not vaccinated people, who are most at risk.

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At a news conference Sunday morning, Arwady said the City of Chicago passed the benchmark of 200 COVID cases per day on Friday, and thus recommended that all city residents over 2 years old wear masks.

Arwady said the city as of Sunday was averaging 206 new cases of COVID-19 per day, but other metrics remain low. The positivity rate is 3.1 percent, 121 people are hospitalized but not in the ICU, and 42 people are in the ICU.

“We have been enjoying well-controlled COVID over these last few months – especially because we have a lot of folks vaccinated,” Arwady said.

Arwady said for context, there were only 13 days in all of 2020 – in early June of that year – when the city was recording fewer than 200 cases per day. Thus, she said, it is “not in and of itself that concerning that we’ve crossed the 200 mark.”

She said the city is not surging in any way like the first surge that resulted in business closures and a statewide stay-at-home order back in March 2020, nor like the second surge in the fall and winter. There may be a surge, Arwady said, “but it may be more like what we saw in our third mini-surge in April, where most of those cases were in people who were vaccinated.”

Arwady also addressed reports that people who are fully vaccinated are still contracting COVID-19 – what are known as breakthrough cases. She said they do happen, but perspective is needed.

“Here in Chicago and across the country, 99.9 percent of vaccinated Chicagoans have not been diagnosed with COVID-19 since being vaccinated,” she said, adding that figure holds up nationally as well.

Arwady’s remarks come days after the Washington Post published a Centers for Disease Control and Prevention PowerPoint presentation that drew headlines pointing out that it indicated that the Delta variant may be as transmissible as chickenpox. It also cited an outbreak this month in cases among residents and visitors to Provincetown, Massachusetts, showing the amount virus in samples collected from vaccinated and unvaccinated cases were virtually identical.

Headlines have also pointed out that in the Provincetown outbreak, 74 percent of the people who were infected with COVID-19 were fully vaccinated.

Arwady again said context and perspective are needed – and reiterated that the most important figure is that 99.9 percent of the people who have been vaccinated have not gotten COVID-19 at all.

Arwady also questioned whether the Ct values stated in the CDC slide deck – representing the amount of viral load detected in the nose – represent a definite corollary to how contagious someone is, as the claim that fully vaccinated people can transmit COVID-19 as easily as unvaccinated people suggests.

“What I don’t want people to take away from that – because we have not seen this around the country – is that the vaccines are not working, and I think that was unfortunately just a conclusion that folks came to,” Arwady said.

Arwady was asked whether fully vaccinated people should also avoid restaurants, bars, and other places where masks cannot stay on inside given the reports about the viral load the fully vaccinated can carry with the Delta variant. Arwady did not make such a recommendation, saying “different people will have different decisions around other activities.” She said she herself had been comfortable going to dinner at a restaurant and taking her mask off while eating the night before.

Of the indoor mask recommendation, Lightfoot said, “It’s not forever, but it’s while we get through this delta surge.”

Arwady noted that during the first COVID surge in the spring of 2020, there were on average about 350 deaths per 50 deaths per day in Chicago. In the fall and winter surge, the numbers were reduced to closer to 180 deaths per week and 25 per day, and in the mini-surge in April, there were only about 50 deaths per week and seven per day. Now, there is one death per day on average.

“Numbers are on the rise. Delta is here. It’s more than 80 percent of the cases we’re diagnosing,” Arwady said. “I expect we’ll see an increase. But the vaccines continue to be highly effective against severe illness.”

Arwady said she expects there will also be surges over the long-term future, but they will be smaller than the ones seen earlier in the pandemic – such that cold and flu season will also be COVID season.

Could business closures or a stay-at-home order be on the horizon if numbers do keep rising?

“We have no goal or current plans to close down Chicago again,” Arwady said. “But we need people please once again to step up.”

Mayor Lightfoot also said at the news conference the city can remain open if people are careful.

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“And let me put a finer point on it – we must be careful to be open. And we can be careful. We’re not helpless against the virus and the variant. We – you and everyone – has the tools right now to fight this virus and the variant. The vaccine, the vaccine, the vaccine,” the mayor said. “That’s’ the tool that we have to help ourselves, help our family, our community and our city.”

As CBS 2’s Marissa Parra reported, Arwady and Lightfoot repeatedly emphasized that the most important action anyone can take to protect themselves from COVID-19 is to get the vaccine.

At the XS Tennis Summer Bash at 5336 S. State St., several people lined up to do what they have been putting off and get the shot.

“My son is 21. He’s afraid to take it,” said Sherece Liendsey, who was vaccinated at the event. “I tried to get him to come down here with me, but maybe if he sees that I took it it’ll encourage him to get it, I don’t want to see him get sick.”

Maurice Washington also got the vaccine Sunday, having decided the day had come to do it.

“it’s coming down to I want to get into compliance with everyone else,” he said.

Also getting the vaccine at the XS Tennis event was 12-year-old Sascha Sanders, who spoke plainly about her motivation.

“I don’t want to die,” she said. “I want to live the rest of my life out without COVID.”

Those ZIP codes are 60633 in South Deering, 60621 in Englewood, 60649 in South Shore, 60620 in Auburn Gresham, 60644 in Austin, and 60628 in Roseland.

“That’s a challenge, but also an opportunity,” Mayor Lightfoot said. “The challenge is you are playing with your life.”

She added, “The Delta variant is real. It is vicious, and it attacks those that are not vaccinated.”

Dr. Maya Green, regional medical director for Howard Brown Health, said at the news conference that placing the blame on unvaccinated people is the wrong approach.

“Let’s be clear – we have to react as one human race. Every day that we fail to do that, we fail together. Every day that we succeed, we succeed together,” she said.

Green noted that Black and brown communities came into the pandemic with a global historical context that has sometimes led to vaccine hesitancy.

“That means me as a vaccinated person, I don’t have time to sit and blame those who have not gotten the chance to obtain vaccinations,” she said.

She emphasized that for those in Black and brown communities in particular who have not been vaccinated, “I speak to you because I know while it may not be easy to make the choice, or easy to access vaccinations, it is necessary.”

Kevin Young, who supervises a street team at South Shore Works, said he was initially hesitant to get the COVID-19 vaccine on the grounds that it neither cures nor 100 percent prevents COVID-19. But after doing research – and hearing from friends who’d had COVID – he went ahead and got the vaccine.

Young said he has five family members and friends who got COVID-19, and two of them died, while three survived. One of those three also had asthma and warned that COVID and asthma at the same time make for a bad situation, and another had to be ventilated. That was enough to motivate him to get the vaccine.

“I feel different because I feel like I’m preventing my family and friends now that I’ve gotten the shots, and my neighborhood,” he said.

Despite Chicago’s positivity rate being over 3 percent, the officials at the news conferences noted there is a staggering difference between those who are vaccinated and those who are not.

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Contributing: Alexander Tin, Sara Cook / CBS News

CBS 2 Chicago Staff