Q&A: How will omicron affect long COVID?
The omicron variant of SARS-CoV-2 now accounts for 95% of COVID-19 cases in the United States, CDC Director Rochelle P. Walensky, MD, MPH, said during a White House briefing on Wednesday.
If omicron causes less severe disease than the delta variant, could any lasting effects of COVID-19 also be less serious?
We asked Ziyad Al-Aly, MD, FASN, a physician at the VA St. Louis Health Care System who studies long COVID, to answer this and other lingering questions about the variant.
Healio: Will people who develop long COVID from omicron experience less severe long COVID symptoms than people who were infected with other variants?
Al-Aly: So, the short answer is that there is still a lot of uncertainty. We don't really know. Omicron, itself, is really new in the U.S. and in the world. Even in South Africa, it's still relatively new.
But what we know about long COVID so far, from all the prior variants, is that the severity of long COVID seems to be a function of the severity of acute illness. What we have so far learned about omicron is that it tends to be milder or a little bit less severe. I’ll caveat that by saying that we're also still learning about omicron. Maybe in the next few weeks, we'll learn that death rates will go up — hopefully, that's not going to be the case. But so far, our knowledge is that omicron seems to be a bit milder than delta. And if that really holds, it may translate into less risk of long COVID.
It does not mean zero risk. It does not mean people should go ahead and get infected with omicron, and not worry about long COVID — that's not the case. But it may translate to less risk, if the idea that it results in less severe acute disease actually holds over time.
Healio: Will the incidence of long COVID be different than with other variants?
Al-Aly: Again, if the acute disease that is brought on by the omicron variant is indeed confirmed to be less severe — what that tells us actually, from prior experience and our prior understanding how of long COVID works, is that it will be associated with less risk, and then subsequently, less incidence of long COVID.
So, again, the major [unknown] here is if omicron is indeed less severe in the acute phase — which, some reports are suggesting it is less severe and doesn't really affect the lungs as much. Clinically and generally, we are seeing sort of less severe infections with omicron. So that, generally, may bode well for long COVID and may show us a reduced risk and reduced incidence for long COVID.
Healio: Is there existing evidence that the symptoms or incidence of long COVID differ depending on which variant caused a patient’s illness?
Al-Aly: So far, with omicron, we still don't know. As we know, with long COVID, symptoms arise or persist for weeks after the initial infection. Generally, with prior variants, what we've seen with long COVID is that the most important feature that that will materially affect the risk of long COVID is really the severity of the infection, whether it's delta or other variants.
The severity of the infection — whether people during the acute phase of the disease, in the first 30 days, actually need to be in the hospital or not — that actually changes the risk profile dramatically. If they needed to be on a ventilator or in the ICU, that increases the risk even further.
Healio: Has your work on long COVID revealed anything new over the past few months that you can share?
Al-Aly: Everybody knows that long COVID is associated with brain fog and fatigue, and you hear about it a lot. But we really clearly now know that long COVID can also affect the kidneys. And so, we published that report recently.
The other thing we are working on is cardiovascular disease and long COVID, and that should come out in the next month or so. We think that will be newsworthy, but it's not really ready for discussion at this point. So, it will be probably in a matter of months.
The major thing was really to shed light on long COVID and the kidneys because a lot of people don't think of the kidneys when they think of long COVID. The most visible to people and patients when they come to the clinic with complaints is fatigue. There is less focus on cardiometabolic consequences, specifically kidney disease. So that's what we highlighted in that report.