If you’ve tested positive for COVID in the past three months, the odds are that you’ve been infected with Omicron. According to the Centers for Disease Control and Prevention, this subvariant accounts for essentially all COVID infections right now. Cases of the Delta variant, which struck several states particularly hard in the summer and fall of 2021, have now decreased and are essentially zero. But just because Delta infections have declined doesn’t mean many aren’t still experiencing the variant’s effects. Often referred to as “long haulers,” some report still experiencing COVID symptoms months after testing positive. According to data taking into account almost 2 million people who tested positive for COVID-19, 23 percent reported post-COVID health conditions. With Omicron spreading more easily than the original COVID-19 virus and Delta, it certainly makes you wonder if it means millions more people in the U.S. will be experiencing long-haul symptoms as well. Since Omicron has only existed for a few months, it’s certainly too early to know for sure what to expect from it long-term, but infectious disease doctors are identifying key ways it differs from Delta, which is leading to some interesting predictions.
How Omicron and Delta compare in the short-term
While many people are reporting that Omicron symptoms are not as severe as Delta’s, Dr. Sonali Advani, MBBS, an assistant professor of medicine at Duke University School of Medicine and the co-medical director of the Duke Infection Control Outreach Network, says it is inaccurate to refer to it as “mild.” “Omicron is not mild,” she says. “[It’s more accurate] to use the term ‘less severe’ because we know that while the vaccinated population has done relatively well tolerating Omicron, there have been some severe cases and the hospital rate of children with COVID during Omicron is five times the rate of what it was with Delta,” she says. Dr. Advani explains that individuals who are vaccinated are less likely to get infected with Omicron (or Delta, for that matter), and if they do get it, are less likely to experience severe symptoms. Dr. William Lago, MD, a family practice doctor with Cleveland Clinic, says that for this reason, the best defense from long haul from either variant is to get vaccinated and boosted. If you have tested positive for COVID, it’s impossible to know for sure which variant you have, though some people are reporting a slight difference in how the symptoms manifest. “With Omicron we are seeing less complaints of losing taste and smell than what we saw with Delta,” Dr. Lago says. Some reports also link headaches being more tied to Delta while Omicron symptoms are similar to cold-like symptoms. But Dr. Advani warns against using symptoms to try to figure out which variant you have. “The data can be biased because it’s self-reported,” she says, adding that this type of data is unreliable. When it comes to symptoms like trouble breathing, heart palpitations, dizziness, brain fog, fatigue, and shortness of breath, both experts say these are symptoms the variants have in common. All the symptoms named here—including the loss of smell and taste more correlated with Delta—can linger months past testing positive for COVID. As more time passes, researchers are learning more about how both Omicron and Delta could affect people long-term.
What researchers know about the long-term effects of Omicron and Delta
When thinking about the long-term effects of either variant, both doctors say it’s important to keep in mind just how new they are; not enough time has passed in either case for anyone to truly understand the long-term effects. Dr. Advani says this is particularly true for Omicron, which is only a few months old. “Something else that makes it complicated is that there is not yet an agreed-upon definition of what ‘long COVID’ is,” she says, adding that the more accurate term is “post-acute sequelae of SARS CoV-2," or PASC. “Even the CDC and World Health Organization have slightly different definitions,” she says. Dr. Advani says PASC is used as an umbrella term and three categories fall within this umbrella. “One is new or ongoing symptoms that persist for more than four weeks after a COVID-19 infection. The second is multi-organ involvement, which is called Mother System Inflammatory Syndrome. And the third is post-intensive care unit illness, [describing] when you get a severe illness after COVID,” she says. These categories apply to both Omicron and Delta when it comes to referring to post-COVID symptoms. Currently, Dr. Advani says that there is not enough data to confirm whether having Omicron makes someone more likely to experience PASC, or “long haul COVID” than Delta. But Dr. Lago says he expects to see more cases of post-COVID from people with Omicron. “This is because what we’ve seen in the past is that it wasn’t just people with severe COVID cases who got long haul syndrome,” he says, reiterating that it’s too early to know for sure what will happen. New studies are emerging connecting COVID to changes in brain structure as well as increased risk for cardiovascular disease. Again, it’s too early to know if both Omicron and Delta could have these long-term effects but Dr. Advani says it’s something researchers are currently looking into. “Seeing studies like these is scary for patients and it’s scary for physicians as well,” she says. She emphasizes that the key is for researchers, physicians, and patients to all continue learning about the virus’s lingering effects, adding that the CDC, WHO, and Infectious Disease Society of America, are all good places to stay informed. Whether you had the original COVID-19 virus, the Delta variant, or Omicron, both experts say that if you are experiencing any long-term symptoms, it’s important to see your primary care doctor. “It’s important to make sure there’s nothing else going on, and if [other factors] have been ruled out, then your doctor can connect you to a long-haul clinic for possible solutions on how to improve your symptoms,” Dr. Lago says. Dr. Advani says these clinics are particularly helpful because they take an interdisciplinary approach, taking the entire body into account. Since so little is known about long-haul syndrome—particularly when it comes to Omicron—both experts say the best defense is doing what you can to prevent getting COVID in the first place, which means getting vaccinated if you aren’t already. Dr. Advani also says that recent data suggests that being fully vaccinated and boosted does reduce your chance of getting post-COVID. If you have already had COVID and are experiencing lingering symptoms, the best course of action is to keep your doctor informed of your symptoms and not to ignore them. The bottom line is that everyone is still learning about COVID’s long-term effects together. “The more time that passes, the better understanding we’ll have of COVID,” Dr. Advani says. She says that this is beneficial not only when it comes to Delta and Omicron, but for other new variants that may arise in the future. You could say that when it comes to figuring out the answers, researchers are in it for the long haul. Next up, get familiar with the risk factors that make it more likely to experience long COVID.
Sources
Dr. Sonali Advani, MBBS, assistant professor of medicine at Duke University School of Medicine; co-medical director of the Duke Infection Control Outreach NetworkDr. William Lago, MD, a family practice doctor with Cleveland Clinic
