Smooth_Imagination t1_is71v6k wrote
Is typical for respiratory viruses influenza can do this too.
But it would also explain the anosmia as an early symptom, the olfactory bulb gets infected and then it can go up the nerve. The anosmia being presumably triggered by the immune response after recognising an infection.
Anthrogal11 t1_is7khyw wrote
I’m curious- if you happen to know, if the olfactory nerve is already inflamed could that potentially impede initial infection as well as transmission to the brain? I ask because some studies have suggested those with allergic rhinitis have lower risks of Covid 19 infection.
ZSpectre t1_is7m1zd wrote
Ooh, I actually really like this question. I'm no expert in immunology, but I'd suspect that because a lot of the immune system cells are involved with allergies (to our detriment), it's making me wonder here if all of those different white blood cells, complement systems, and antibodies that may or may not be involved with allergic rhinitis may somehow provide enhanced immunity(?). My educated guess is that the innate immune system may likely be involved, but I can't remember how that's affected by something like allergic rhinitis. Looking forward to someone passing by to either confirm, clarify, or refute this :)
MoreTrueStories t1_is85li9 wrote
Allergies are one of the leading causes of sinus infections (which are typically caused by viruses). That suggests that inflammation will not impede, but rather precipitate the infectivity of SARS-CoV-2.
Following infection, a systemic immune response is mounted, characterized by increased serum concentrations of chemokines and pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor (TNF), and the appearance of activated monocytes, followed by SARS-CoV-2-specific immunoglobulin M (IgM), IgA, and IgG antibodies and interferon-γ-producing T cells. This concerted action of the immune system controls the replication of SARS-CoV-2.
With that said, the question is whether or not the preexisting inflammation would also result in the immune system detecting the virus earlier than it would in subjects without active allergies. It does seem likely that patients with already elevated levels of immunoglobulin would help detect the virus sooner and would likely result in better outcomes (i.e. no PACs 'long covid).
/u/Anthrogal11 my hypothesis is that you would have a higher rate of infection but also be more likely to present as asymptomatic. Something that may confound the above is if your allergies are so bad that they significantly restrict airflow through your sinuses.
ZSpectre t1_isauhp8 wrote
Thanks a ton for the reply. If I'm getting what you're saying correctly (and this may be a fun review of immunology for me since I was no big fan of the subject back in the day), I'm first thinking of an analogy comparing the difference between a walled fortress with a few soldiers versus one that would only have a small fence but a ton more soldiers, weapons, and tracking devices. For those passing by, the walled fortress would be like the blood vessel's "normal state" while the latter would be the "inflamed" state seen both in allergies and active infection.
While someone with allergies would have the latter state much more often with the weakened barrier (inflammation causes more porous blood vessels likely to function as a means to let more white blood vessels come in), I'm first guessing that this would be the main reason why it would precipitate the infectivity of viruses that happen to come by (as said in your first point).
In other words, all viruses that get into the upper nose may have an easier time getting through the small fence. And while the ones that cause allergic rhinitis may have an easier time evading the soldier's detection systems (perhaps more nimble / more stealthy), the question all 3 of us are talking about is whether or not SARS-CoV-2 may have a more difficult time avoiding getting tagged by the soldier's detection systems despite more easily getting in. (compared to a normal person who starts out with the walled fortress, maybe the virus may have a tougher time coming in, but if they ever do, the soldiers would have to go through "normal protocol" of calling for back up, weapons, and tagging systems, which all could take up extra time)
And to translate your hypothesis, perhaps much more SARS-CoV-2 viruses get in with a weak fence, but they likely won't do much after that since perhaps getting tagged more easily would make the rest the soldiers in the other fortresses much more aware of their presence (even if they get to other parts of the body, they have a shining beacon on them). The confounder is how allergies may just so happen to supplement the weak fenced compound with a big wall of slime.
FascistFeet t1_isiwdkm wrote
Good metaphor. Thank you.
Anthrogal11 t1_is7myux wrote
Thanks! I’m super curious both as an academic and because I have pretty awful allergic rhinitis all year (I know, the jokes write themselves). I’m triple vaxxed but I had just graduated at beginning of pandemic and worked in a service capacity throughout. My son got it and we live in close quarters. There was no isolation. I’ve managed to not catch it (so far). I’m so curious if the curse of severe allergies has potentially provided a benefit in terms of avoiding Covid. Thanks for your response and insights!
sgnirtStrings t1_is85na2 wrote
I'm 4x original vax and 1 new bivalent vax. Never gotten it before. Also a sufferer of severe allergies and allergic rhinitis for >10 years. That's my random data point.
Random aside: I've been doing allergy shot immunotherapy for ~4 months and holy hell it works. My shallow research into a couple papers reveal a theory of how it might work: I'm simply exhausting the differentiated immune cells that I have for each specific allergen. And then after a certain length of time being consistently exposed, the cells start going "whoops I guess I give up, time to die". And that's possibly why allergic immunotherapy can cure people's allergies.
Just mentioning that because I wish someone told me about the treatment 10 years ago! Used to take 1-2 antihistamines a day. Now I take none. (And I'm talking allergies to 40+ different pollens in the area).
Anthrogal11 t1_is9si16 wrote
Thanks! I have talked to my allergist about this because I’m on prescription antihistamines twice a day. I’ll talk to them further. I appreciate your insights!
Smooth_Imagination t1_is7p9v7 wrote
Why thankyou for bringing that to my attention. I did not know allergic rhinitis was associated with reduced risk.
Well, I'm going to pour out some thoughts. Different densities of eosinophils, also release of histamine, these have been noted altered in COVID19.
It could be so many things, such as production of more neutralising mucous, different viscosity.
Mast cell stimulation is involved in allergy and these two play a key role in antigen presentation and viral recognition.....
Neutrophils too are a key part of COVID.
https://pubmed.ncbi.nlm.nih.gov/22918213/
Pendrin is also upregulated in asthma like allergic rhinitis and asthma seems also protective in COVID.
https://www.jimmunol.org/content/181/3/2203
It should induce antiviral effects by increasing the export of natural antiviral compounds including chloride ion and SCN.
https://www.atsjournals.org/doi/full/10.1165/rcmb.2018-0304OC
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3208616/
I would assume that the environment is already rather hostile to viruses. The existing inflamed neutrophils and the increased presence of other immune cells, the change in the thickness of the mucosal tissue in allergic rhinitis and the possible production of more antiviral mucous may be involved in a faster early response.
It might alter the chances of developing symptoms, it might alter chances of the virus establishing an infection. I would imagine it leads to a heavier early response and reduced permisiveness to infection, which protect against heavier infection.
Presumably the change in the nose is not just seen there but affects the upper and lower airway too.
Anthrogal11 t1_is7py3w wrote
Thanks so much for your thorough and informative response! I appreciate your insights and the links. I’ll definitely take the time to review.
dinguskhanbmon t1_isdjmgf wrote
Always confused me why loss of smell is seen as almost pathognomonic for Covid. Lots of other colds/flus make you lose your smell/taste.
moronic_imbecile t1_is7n42d wrote
Do you have a citation for the influenza brain invasion? Not that I don’t believe you would it would be nice to see.
I wonder how much of this is confounded by (a) the obscenely massive dose they were given which is 2.5x10^6 plaque forming units which is a metric fuckload of virus, and (b) the fact that the monkeys were killed while having an active infection. Doesn’t the BBB break down during death? Couldn’t euthanizing them explain some viral infiltration?
BlewByYou t1_is8e30c wrote
As a retired firefighter/paramedic (29 yrs) this completely changes how I thought of “Rescue Mung” the yearly “kick you ass flu/bronchitis” we got yearly. Crap. And I was worried about cancer before this (re: cancer in the fire service)
UrbanFootprint t1_is7rrvg wrote
You seem very knowledgeable in this area. I’ve had no taste or smell now for 3 months since my infection. It was my only symptom and the only way I knew I even had Covid. Is there any way to ease this immune response to ease the anosmia?
Larnak1 t1_is9xhn7 wrote
I'd assume it's less a question of easing the immune response, as more about healing the damage that virus and immune response have dealt.
Typically, viruses infect cells, and the immune system identifies those cells and kills them before they can produce more virus.
I didn't look into the background of this, but there's certainly a possibility that not all of the damage is always reversible.
sotoh333 t1_is8fblf wrote
No, it's not. Influenza doesn't do this.
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