Evidence is mounting about the dangers of the delta variant and how mask-wearing is essential to bring it under control, according to a government slideshow dated Thursday. The slideshow, compiled by an official with the Centers for Disease Control and Prevention, lays out what is known about the delta variant, which now accounts for the vast majority of COVID-19 cases in the United States. Earlier this week, the CDC recommended that people in COVID-19 hotspots resume mask-wearing in indoor public spaces in regions with high coronavirus transmission. The agency had been criticized for making the recommendation without adequately backing up the reasons for the policy shift. But the slideshow, first made public by The Washington Post, appears to do just that. CDC declined to comment late Thursday on the slideshow or its contents. It shows that those who are vaccinated are three times less likely to get COVID-19 than those who are unvaccinated. Once infected, though, vaccinated people are just as contagious as someone without that protection — meaning they need to wear a mask and keep their distance to avoid passing on the virus. “The data makes a pretty compelling justification for why we need to go back to mask wearing and other public health measures,” said Dr. Charles Chiu, an infectious disease specialist at the University of California, San Francisco. “I do think it’s because of the delta variant.” ‘I thought I did everything right’:The fully vaccinated are frustrated by CDC’s changing mask advice
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Several researchers also questioned why the data was not released two days earlier, when the CDC made its new mask recommendations.
In a Tuesday briefing, CDC Director Dr. Rochelle Walensky downplayed the possibility that a vaccinated person could pass on the virus, without giving the details about the viral load contained in the slideshow.
Dr. Leana Wen, an emergency physician and former Baltimore health commissioner, said the slideshow suggests CDC is worried about the risks of delta to the vaccinated, but that’s not what Walensky focused on during her Tuesday briefing, Wen said.
“I don’t know what to make of it, honestly,” she said after seeing the slideshow. “Why wasn’t this level of data revealed to the American public two days ago?”
And, she wondered aloud, why countries like the United Kingdom and Israel are still generating so much more COVID-19 data than the U.S.
It would be simple, for instance, to ask people as they’re tested for COVID-19 whether they’d had their shots, she said — but the CDC doesn’t collect the data, so it’s not clear what percentage of transmissions are from the vaccinated.
Dr. Paul Offit, who directs the Vaccine Education Center at the Children’s Hospital of Philadelphia, said he’s very concerned about the current state of America’s pandemic.
Last summer, before there was a vaccine, there were about 80,000 new COVID-19 cases reported every day and nearly 500 deaths — almost exactly the same count as today although half the population is vaccinated and many other have immunity because they’ve already been infected.
Why haven’t things gotten better, Offit asked rhetorically. “The answer is we have enough people in the population that are susceptible – and we have a virus that is clearly more contagious.”
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