What Are Your Chances of Catching the Delta Variant If You're Fully Vaccinated? Chicago's Top Doc Weighs In

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If you're fully vaccinated against COVID-19, how likely is it that you could contract the rising delta variant that experts warn is more transmissible? Chicago's top doctor weighed in Tuesday.

"So this is where, again, luckily, the vaccines have continued to perform well and we shared some data, Pfizer Moderna and J&J have now put some data out showing that their vaccines do remain protective against the delta variant, though you lose a little bit," Chicago Department of Public Health Commissioner Dr. Allison Arwady said.

Arwady said that during a study in the U.K., the two-dose Pfizer vaccine was about 50% protective against the alpha variant after one shot and then after both shots of the two-dose series, the level of protection increases to roughly 93%.

"And then against the delta variant, if you only had one dose, it only fell to about 39% protected I think, I don't have the exact numbers in front of me, but like 35 to 40% protected, which is not well protected," Arwady continued. "But after two doses of that mRNA, that Pfizer vaccine, even against the delta variant, it fell from about 93% protected to about 88% protected."

Arwady said "88% protected is still very, very good and then importantly, the protection against hospitalization and death remains really good."

Currently, little data has been released showing just how effective the Johnson & Johnson is at protecting against the Delta variant, though it is believed that the single-shot vaccine does offer protection against the variant.

Dr. Scott Gottlieb, former Food and Drug Administration commissioner, reportedly said the Johnson & Johnson vaccine appears to be about 60% effective against the delta variant.

Arwady also noted that the vast majority of hospitalizations and deaths due to COVID-19 in recent months have been in people who are unvaccinated.

"We've seen here across the whole country, just in May, you know, 99% of those hospitalizations and deaths in people who are not vaccinated," Arwady said. "And here in Chicago, going all the way back to January when vaccines were kind of first fully available, 97% plus of the people, you know, living here in Chicago who have been hospitalized or have died from COVID since then, people who are not fully vaccinated."

"And that has remained true, even as variants have emerged, so you know, luckily at this point, the vaccines continue to perform well, especially for those severe outcomes against COVID," she added.

Arwady has previously addressed concerns surrounding the delta variant on several occasions, most recently saying last week that she did not believe the variant would cause a surge in coronavirus cases like those seen in 2020.

While Arwady and other officials have predicted the delta variant will become the dominant variant in Chicago and Illinois in the coming months, "that in and of itself is not necessarily a cause for alarm," she said Thursday.

"My worry is if we see a surge it would very much [be] concentrated in unvaccinated portions of Chicago, but I don't think, unless we see a new variant, we would be set up for the kind of major surge that threatens to overwhelm the health system where we need to do the big major shutdowns," she said. "You know, the hope is that we would be able to control it and really keep pushing vaccine. I'd of course rather avoid that and just try to get folks vaccinated now, but that's where I think we're headed."

Arwady noted, however, that new variants continue to emerge and could threaten vaccine efficacy.

"The real question for me is, do we see variants emerge where the vaccine is no longer as effective and that would be when we would probably need to be talking about boosters," she said.

Still, Arwady said any of the three vaccines currently being used in the U.S. continue to show good results as far as protection.

"Right now there is no recommendation if you are fully vaccinated with any of those three vaccines that you would need to get another type of vaccine or that there's a need there," she said. "And really the news continues to be good where we look at this question of will we need boosters. There was just some additional studies out that have been, you know, this is one of the biggest questions and the news really keeps looking promising that the protection for the variants we have now for the vaccines that we have now is looking quite good and quite long lasting and I'm not anticipating that we will be seeing large scale booster shots anytime very soon for the broad population."

So far, the Illinois Department of Public Health has identified 174 cases of the variant in the state as of data reported Monday. That's compared to 6,814 cases of the variant first reported out of the U.K. known as the alpha variant, which is likely the most prolific-strain in the state of Illinois.

NBC Chicago/Associated Press
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