Did COVID improve my sense of smell?

May 5, 2023 7:29 AM

In the weeks following my first COVID vaccinations, I noticed that my sense of smell started to get clearer. Long hampered by allergies and about 10 years of smoking, food and particularly outdoor plant smells were suddenly easier to detect. But correlation ain't causation, right?

But then with each booster, I'd notice a boost to my olfactory sensitivity, especially a few weeks beyond the date of the shot. This would fade over time, yet subsequent shots brought it back. I started noting this in my CDC check-in messages.

I got my first actual COVID infection in March this year. This was in the thick of allergy misery for me, but my allergy sinus congestion and pain evaporated as my immune system had something real to deal with. Didn't lose smell or taste, but it was diminished. Now, about six weeks on, I feel back to normal if a little brain-foggy, spring allergies symptoms about typical for May. But my sense of smell is the most vivid since I was a small child. I can smell people and pets as I walk past them outside, and can smell honeysuckle from 10 meters away, the marshy smell of mud after a downpour, last night's cooking the next day, all those sensory inputs that could make the world seem too intense to a six year old.

So is this a coincidence? I can't find any reference to this kind of side effect, though it's also obviously going to be drowned out by long COVID smell-and-taste problems. Anyone want to take a go at an explanation to investigate or notice something similar in their own experience?

posted by bendybendy to Health & Fitness (9 answers total)

Off the top of my head I would guess that an extended period of wearing a mask has given your nose a respite from the everyday low level irritations as well as the larger ongoing allergy attack and it’s been able to heal back to a level you haven’t known in many years.

Definitely just a guess though.
posted by Tell Me No Lies at 7:40 AM on May 5, 2023 [6 favorites]

(The apparent immediate connection to the vaccinations I would attribute to those drawing attention to what was going on, much like emergency room personnel find themselves believing (incorrectly) that there is a higher incidence of injuries during a full moon.)
posted by Tell Me No Lies at 7:43 AM on May 5, 2023

I had a similar reaction to vaccinations, one that I noticed long before covid. Definitely gave my immune system something real to do besides attack my body over pollen. I agree with the above that masks have also heightened my sense of smell.
posted by Bottlecap at 8:04 AM on May 5, 2023 [2 favorites]

Best answer: Your immune system may have contributed. Smoking and chronic sinusitis (pollution etc etc) inflame/damage the receptors for taste and smell. Your big immune response to the vaccines and virus may have done a cleanup job on some long-term damage. As a former smoker (and chronic sinus-sufferer) myself, I've been interested for a long time about whether that damage ever heals/self-repairs, and the science generally points to yes (as does anecdata - most smokers report significant early improvement and then slower continued improvement over time). You are always growing new taste buds and nose cilia and stuff, and when you stop hurting them they grow back nice and strong, but if you had low-grade chronic inflammation of the tissue where those grow and/or neural pathways that communicate that info to the olfactory processing system, and your immune response finally cleared that up, you could see improvement in that way.

I would not assume that other people's loss of those senses is the same mechanism as your improvement. COVID appears to cause vascular damage, and near-total loss of taste and smell to this commonly-reported extent has previously been primarily associated with brain damage or very serious tissue damage in the mouth and nose (like from radiation for cancer, or high heat inhalation). We do know that the earliest variants of unvaccinated COVID did that kind of lung tissue damage, but I haven't seen any significant reports of, like, unmistakable symptoms of oral/nasal tissue destruction on that level.

So I do think it seems more likely that your immune response solved a problem you already had, rather than either the virus or vaccine causing a problem that accidentally resulted in an improvement for you.
posted by Lyn Never at 8:05 AM on May 5, 2023 [6 favorites]

People have had lots of interesting experiences just after COVID vaccines and infection. Siderea had a fungal infection on her tongue clear up (temporarily). Anecdotally, some people with menstrual systems reported menstrual discharge after getting one of the mRNA shots. So I am inclined to say that yes, there was some kind of cause-and-effect for you where vaccines and infection were among the factors that led to your olfactory changes. But also I would guess that it will be hard to accurately work out the precise mechanisms involved.
posted by brainwane at 8:57 AM on May 5, 2023

Anecdotal, but a man in my art class could not smell anything for many years due to an accident. He got covid and when he did, his sense of smell returned briefly.
posted by Ms. Moonlight at 9:30 AM on May 5, 2023 [1 favorite]

Also anecdotal: my mother has had parosmia ("distorted" sense of smell) since her covid infection two years ago. As she describes it, it's sensitivity to the point of discomfort - the smells aren't wrong but a particularly intense version of what they should be. I would imagine its possible to have a less intense, functionally useful increase in sensitivity.
posted by Ballad of Peckham Rye at 2:46 AM on May 6, 2023

Also anecdotal, but I lost my sense of smell due to COVID (pre-vaccine, for what it's worth), and it returned over the course of about 6-8 weeks. When it came back, everything was almost the same, but specifically onions (and things that smell like onions) smelled different -- more distinctive and more intense, like there was a component of the smell I wasn't picking up before but now am. Very weird.
posted by egregious theorem at 5:36 AM on May 6, 2023 [1 favorite]

Response by poster: Thanks for all the insights and experiences. Now, a month after posting, my sense of smell has returned to it's baseline hampered state, with seasonal pollens and molds doing their job.
posted by bendybendy at 5:50 AM on June 5, 2023 [2 favorites]