Delta Variant: What to Know About the New Version of Coronavirus Sparking Concern

Here's what we know so far about the variant itself and what is being seen in Chicago and Illinois

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Concerns surrounding the delta coronavirus variant are rising in both Chicago and Illinois, but what is it about the new variant that has some worried?

Here's what we know so far about the variant itself and what is being seen in Chicago and Illinois.

What is the delta variant?

The delta variant is one that was first detected in India in December. Scientists believe the variant may be the most aggressive and contagious strain of the COVID-19 virus seen so far.

According to the Centers for Disease Control and Prevention, the delta variant, also known as B.1.617.2, has shown increased transmissibility and could result in reduced protection from current COVID vaccines.

The version of the coronavirus has been found in more than 80 countries since it was first detected in India, according to the Associated Press. It got its name from the World Health Organization, which names notable variants after letters of the Greek alphabet.

What is it about the variant that is raising concern?

Experts say the delta variant spreads more easily because of mutations that make it better at latching onto cells in our bodies. In the United Kingdom, the variant is now responsible for 90% of all new infections. In the U.S., it represents 20% of infections, and health officials say it could become the country’s dominant type as well.

It's not clear yet whether the variant makes people sicker since more data needs to be collected, said Dr. Jacob John, who studies viruses at the Christian Medical College at Vellore in southern India.

Last week, the World Health Organization warned that delta is the fastest and fittest coronavirus strain yet, and it will "pick off" the most vulnerable people, especially in places with low vaccination rates, CNBC reported.

"This newer Delta variant played a big role in the huge surge of cases that we saw in India," Chicago Department of Public Health Commissioner Dr. Allison Arwady said.

"It took a little bit of time for it to take hold, but then the big surge," she continued. "And I know a lot of you saw just you know hospitals running out of oxygen, a lot of deaths was largely driven by this delta variant, and then we have seen this delta variant in more than 90 countries around the world. It is definitely here in Chicago. It is in, I believe, every US state at this point."

Arwady said the delta variant is more contagious than the alpha variant, also known as the B 1.1.7 or UK variant, which is now the dominant strain in Chicago.

"The alpha variant - the one that originally emerged from the UK - was about 50% more infectious or more contagious than the original, and then the Delta looks like it's probably maybe 50% contagious, more contagious, again, even than alpha."

According to Arwady, that means "you don't need as much exposure to the virus to get sick from it."

Do vaccines work against the variant?

Studies have shown that the available vaccines work against variants, including the delta variant.

Researchers in England studied how effective the two-dose AstraZeneca and Pfizer-BioNTech vaccines were against it, compared with the alpha variant that was first detected in the U.K.

The vaccines were protective for those who got both doses but were less so among those who got one dose.

Arwady reported Tuesday that a recent study showed the Pfizer vaccine was 84% effective against the variant after two doses, but only 34% effective after the first dose.

Moderna also announced Tuesday that a new study showed its vaccine also produced promising protection in a lab setting against the delta variant and others currently circulating. The data hasn't yet been peer-reviewed.

“As we seek to defeat the pandemic, it is imperative that we are proactive as the virus evolves. We remain committed to studying emerging variants, generating data and sharing it as it becomes available. These new data are encouraging and reinforce our belief that the Moderna COVID-19 Vaccine should remain protective against newly detected variants,” Stéphane Bancel, chief executive officer of Moderna, said in a statement.

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

"The biggest thing still is that the vaccine remains really very well protected against it," Arwady said Tuesday. "So across all types of variants here in Chicago, since a vaccine was fully available, 98% of our deaths 97% of our hospitalizations have been in people who were not fully vaccinated and that has been holding, even for the delta variant. So, broadly, we definitely have some concern about the delta variant, because if there are unvaccinated social networks or neighborhoods in Chicago, even a single case is more likely to spread and more likely to cause more people to get COVID and so, the most important thing of course is to get vaccinated."

Is the variant already in Illinois?

Yes. In fact, the delta variant is expected to become the dominant strain for Illinois cases by the fall, Gov. J.B. Pritzker said Monday.

Pritzker said "the delta variant that sent Israel back into mitigation is a growing presence in Illinois" as he continued to encourage residents to get vaccinated.

"We expect it to dominate our cases statewide by the fall," he said.

So far, the Illinois Department of Public Health has identified 84 cases of the variant in the state as of data reported Sunday.

That's compared to 6,505 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.

Cases of the delta variant are roughly doubling every two weeks, a trajectory that has some officials worried.

“We are seeing [the Delta variant] grow here in Chicago. We’ve had at least 70 cases detected here already,” Arwady said last week.

Should you still wear a mask due to the variant?

The World Health Organization on Friday urged fully vaccinated people to continue to wear masks, social distance and practice other COVID-19 pandemic safety measures as the delta variant spreads rapidly, CNBC reported.

"People cannot feel safe just because they had the two doses. They still need to protect themselves," Dr. Mariangela Simao, WHO assistant director-general for access to medicines and health products, said during a news briefing from the agency's Geneva headquarters.

"Vaccine alone won't stop community transmission," Simao added. "People need to continue to use masks consistently, be in ventilated spaces, hand hygiene ... the physical distance, avoid crowding. This still continues to be extremely important, even if you're vaccinated when you have a community transmission ongoing."

Arwady noted, however, that Chicago and Illinois are continuing to follow CDC guidance.

"The WHO is making that recommendation for the whole world. The CDC, on the other hand, has made the recommendation that people who are fully vaccinated do not need to mask, whereas people who are unvaccinated should continue to mask. Of course we see in truth, there are certainly some people here in Chicago who are unvaccinated who have probably dropped their masks, even indoors. And so, right now, while our outbreak remains in very good control locally, even with the delta here, there is not a reason to adjust that guidance, and we would be sticking with the CDC guidance that says if you're fully vaccinated you don't need to be wearing a mask indoors. But... if you're fully vaccinated and you have concerns right- you have an immune system problem, you have kids who aren't vaccinated, you are worried about people in your social network who may not be vaccinated, or you just want to be extra careful - certainly individuals are continuing in some cases to continue wearing that mask and I welcome people to do that."

She noted that an increase in cases in Los Angeles, many of which have been attributed to the delta variant, has led to a new recommendation to continue masking indoors.

"They're not mandating but they did put a recommendation back in place that at least indoors right now, that everybody go back to potentially wearing masks so I don't want to rule out, you know, that this could be something that could be a recommendation again in the future," she said. "We're keeping a really close eye on our local data here, on our genomic surveillance, and if there is a need to make a change to that recommendation it's something we would do. But right now, I think we are feeling good about where we are."

Pritzker, who wore a mask to a recent public event, said he was doing so out of an "abundance of caution" as concerns surrounding the delta variant rise.

He encouraged residents to continue to "use your mask accordingly."

"I would say from my own perspective if you're going into a heavily crowded area, you don't know if somebody is not vaccinated and so you should just bring your mask with you and keep safe," he said.

Vaccines have shown to be largely effective even against more contagious strains of COVID-19, according to studies.

How can the variant be prevented?

Dr. Temitope Oyedele, infectious disease physician at Cook County Health, says that the only way to combat the delta variant is to vaccinate more residents, giving the virus fewer avenues of transmission.

To that end, officials are moving away from mass vaccination sites, with sites like the United Center set to close, and more towards hyper-local, door-to-door type vaccination events to get shots into more arms.

"The lessons here at home and across the world are a harbinger of what could happen here, particularly in low vaccinated areas, if we don't see a higher uptake of the vaccine across Illinois," Pritzker said. "This is very real. I implore all residents, if you have friends and family on the fence, share with them the life-saving benefits of these free vaccines and encourage them to remain masked until they are fully vaccinated."

NBC Chicago/Associated Press
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