Breakthrough infections of the coronavirus are increasing in Chicago and Illinois, but health experts say it's likely that the symptoms you experience will depend on the vaccine.
Chicago Department of Public Health Commissioner Dr. Allison Arwady, the city's top doctor, said the omicron variant isn't necessarily bringing with it a new set of symptoms, but with vaccines now widely available, many are experiencing milder cases, depending on their vaccination status.
"The symptoms that we're seeing are not different with omicron than they were with delta, than they were with the original. It's just that we are seeing more what we call breakthrough infections," Arwady said Wednesday. "So the vaccines continue to protect, but not as well against infection, although they continue to protect beautifully against severe illness."
Arwady said that now, those who are fully vaccinated aren't necessarily getting "seriously ill and having fevers for days and difficult breathing," but are instead experiencing a more mild illness.
"They may only feel like they have a cold," she said. "That's good because they're not getting seriously sick, they're not threatening the healthcare system, but it's certainly of some concern because they do have the potential to transmit to others."
The unvaccinated, however, are experiencing similar symptoms to early on in the pandemic, Arwady said.
"People who are unvaccinated present in the same way: fevers, cough, chills, shortness of breath," she said.
Arwady's comments echo those of other medical experts who are watching omicron cases.
Dr. Katherine Poehling, an infectious disease specialist and member of the Advisory Committee on Immunization Practices, told NBC News last week that a cough, congestion, runny nose and fatigue appear to be prominent symptoms with the omicron variant. But unlike delta, many patients are not losing their taste or smell.
The evidence so far, according to Poehling, is anecdotal and not based on scientific research. She noted also that these symptoms may only reflect certain populations.
Still, CDC data showed the most common symptoms so far are cough, fatigue, congestion and a runny nose.
In New York, where cases continue to surge, an ER doctor who became known on social media during the pandemic for his documentation of the battle against COVID, reported breakthrough cases he has seen in those with booster shots experienced "mild" symptoms.
"By mild I mean mostly sore throat. Lots of sore throat," Craig Spencer wrote on Twitter. "Also some fatigue, maybe some muscle pain. No difficulty breathing. No shortness of breath. All a little uncomfortable, but fine."
Cases in people who were fully vaccinated with either Pfizer or Moderna's vaccine, but not boosted, remained mild, but slightly more intense.
"More fatigued. More fever. More coughing. A little more miserable overall. But no shortness of breath. No difficulty breathing," he wrote.
For those with Johnson & Johnson who were not boosted, he wrote the patients "felt horrible," with fevers, fatigue, coughs and shortness of breath, but did not require hospitalization or oxygen.
In the unvaccinated, however, the symptoms were more severe.
"Almost every single patient that I’ve taken care of that needed to be admitted for Covid has been unvaccinated," Spencer wrote. "Every one with profound shortness of breath. Every one whose oxygen dropped when they walked. Every one needing oxygen to breath regularly."
Dr. Angelique Coetzee, the South African doctor who first raised the alarm over the new strain, told the BBC that she started to see patients around Nov.18 presenting with "unusual symptoms" that differed slightly to those associated with the delta variant.
"It actually started with a male patient who's around the age of 33 ... and he said to me that he's just [been] extremely tired for the past few days and he's got these body aches and pains with a bit of a headache," she told the BBC.
The patient didn't have a sore throat, she said, but more of a "scratchy throat" but no cough or loss of taste or smell — symptoms that have been associated with previous strains of the coronavirus.
Coetzee said she tested the male patient for COVID, and he was positive, as was his family, and then said she saw more patients that day presenting with the same kinds of symptoms that differed from the delta variant.
Other patients she had seen so far with the omicron variant had also experienced what she described as "extremely mild" symptoms, and she added that her colleagues had noted similar cases.
Similarly, in the first U.S. case, the president's chief medical adviser Dr. Anthony Fauci said the person was vaccinated but had not received a booster shot and was experiencing “mild symptoms.”
Moderna CEO Stephane Bancel told CNBC that omicron symptoms reported in South Africa may not be a good predictor of the variant's virulence in other parts of the world, because the country has a much younger and healthier population than European nations and the U.S.
For now, Arwady urged anyone who has a cold to assume it is COVID until testing proves otherwise.
"I would rather people err on the side of assuming right now, with the numbers like they are, regardless of that new symptom, that it is likely to be COVID," she said.
According to early findings of a study by the U.K.'s Imperial College London, there is no evidence that the omicron variant is any less severe than the delta variant based on reported symptoms.
"The study finds no evidence of omicron having lower severity than delta, judged by either the proportion of people testing positive who report symptoms, or by the proportion of cases seeking hospital care after infection," a research team led by professor Neil Ferguson said Friday in a blog post accompanying the study.
The data included 24 hospitalizations of patients suspected of having the omicron variant, with researchers saying "hospitalisation data remains very limited at this time." The study is yet to be peer-reviewed.
In Illinois, hospitalizations have been rising.
Allan Spooner, CEO of Franciscan Health South Suburban Chicago, said Monday that COVID-19 cases at the system's hospitals have grown four times over the past three weeks - from 10 to 42%. More than 70% of critical care patients have COVID-19, with 30% of them requiring a ventilator, he said.
Physician and staff infections have also risen as the latest surge increases, Spooner said, "exacerbating an already precarious staffing shortage across health care."
Rex Budde, president and CEO of Southern Illinois Healthcare, reinforced a similar message.
"The number one thing that we can do is get vaccinated," he said.
Budde said 40% of the Carbondale hospital's medical beds are occupied with COVID patients. As is the case at other health systems, he said to treat COVID patients, the hospital has had to pull resources from other parts of the facility and delay treatment for others, including stroke and heart care patients.
"People are dying from this virus that don't need to die," he said. "Imagine being a nurse or a physician or a care tech who have to look at this and deal with this every single day. The staff is worn out. Nurses are worn out. Physicians are worn out."
Despite some differences reported between omicron and delta, Chicago experts say looking at the symptoms is not enough.
"The trick is you're not going to be able to tell the difference between omicron, delta, lambda, plain COVID from the beginning," Dr. Emily Landon, infectious disease specialist and chief hospital epidemiologist at University of Chicago Medicine, said. "Influenza or even common rhinovirus causes most of our common colds in the winter. You're not going to know the difference between those if you just look at your symptoms. For many people, those symptoms are overlapping. And while there are some parts of the Venn diagram like taste, loss of taste and smell, or common COVID than these other things, there's a lot of overlap. You're just not going to know especially at the beginning of an illness, what kind of illness you have. You have to get tested."
And getting tested won't necessarily tell you if you have the omicron variant, Landon said.
"When you get a COVID test they're just looking for whether or not you have COVID," she said. "They're not on which kind of in order to figure out the exact strain of COVID. You have to do this thing called sequencing, which takes a lot longer. It's much more intensive. You certainly can't get that back in 24 hours, and it's only done by specialized labs."
Overall, the symptoms for COVID reported by the CDC include:
- Fever or chills
- Shortness of breath or difficulty breathing
- Muscle or body aches
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting