Immunity is a matter of degrees, not absolutes and that lies at the heart of many of the COVID-19 pandemic’s biggest questions. Why do some people become extremely ill and others don’t? Can infected people ever be sickened by the same virus again? How will the pandemic play out over the next months and years? Will vaccination work?
The new coronavirus seems to rely on early stealth, somehow delaying the launch of the innate immune system, and inhibiting the production of interferons—those molecules that initially block viral replication. “I believe this delay is really the key in determining good versus bad outcomes,” says Akiko Iwasaki, an immunologist at Yale. It creates a brief time window in which the virus can replicate unnoticed before the alarm bells start sounding.
Immune responses are inherently violent. Cells are destroyed. Harmful chemicals are unleashed. Ideally, that violence is targeted and restrained; as Metcalf puts it, “Half of the immune system is designed to turn the other half off.” But if an infection is allowed to run amok, the immune system might do the same, causing a lot of collateral damage in its prolonged and flailing attempts to control the virus.
This is apparently what happens in severe cases of COVID-19. “If you can’t clear the virus quickly enough, you’re susceptible to damage from the virus and the immune system,” says Donna Farber, a microbiologist at Columbia. Many people in intensive-care units seem to succumb to the ravages of their own immune cells, even if they eventually beat the virus. Others suffer from lasting lung and heart problems, long after they are discharged. Such immune overreactions also happen in extreme cases of influenza, but they wreak greater damage in COVID-19.
This is precisely what I experienced with Avian flu 4yrs ago. It ran into double pneumonia, sepsis then septic shock, my lungs, kidneys & heart failed & rounded it off nicely with severe ARDS. I was on the ultra vulnerable list for 2 months after waking from 2 month coma, crashing regularly & constantly monitored for stroke, clotting, seizures etc etc etc. Long term cognitive dysfunction, weakness, fatigue, neuropathy, myopathy- you name it, ‘Covid’ isn’t special when it comes to leaving behind unwelcome friends.
I’ll never know whether the pleural effusion last year was because of weakness left by ARDS or its my CLL, I’ll never know if the forgetfulness is Ibrutinib or normal cognitive dysfunction associated with intensive care, weakness, fatigue ditto - bit of a mine field, forgetting the pseudo RT for a second, why did I fit a couple of month ago? CLL related? Medication intolerance? Sepsis legacy? Critical care legacy?
Atleast I can start crossing things back off list, diabetes 2 is under control and has possibly ‘flipped back’.
An excellent and highly informative read Jackie. I love the complexities of the immune system but would appreciate its exquisite complexity much more if my body didn’t have a flawed one!
At an academic level I read this material in awe but it also reminds me that we have cancer of the B cell lymphocytes which hits at the most fundamental building blocks of human protection. During a pandemic like this, how unfortunate we are to have a virus that relies on a sturdy innate system producing pathogen killing T and B cells which also produce the antibodies that ‘mop up’ very selectively in the adaptive system and create ‘memory protection’. My first line of defence is looking better in that treatment has partially restored my bone marrow function allowing it to start producing the necessary cells. However, I’m aware my adaptive system is severely compromised by having hypogammaglobulinaemia (low immunoglobulins/antibodies).
This is a very scary scenario to take our unpredictable, wonky and malfunctioning immune systems into but as they say, the immune system is very complex so we have no way of knowing what the true response or outcome might be.
It’s a sneaky virus for sure that doesn’t play fair even with healthy people, let alone us CLLers with our wonky systems 😕
I read somewhere the words that it is‘exquisitely adapted’ to infect humans and evade our immunological defence mechanisms. Strange considering it’s a bat virus.
Oh yes, I know this is humanising it and lightheartedly crazy ( too much isolation) but COVID-19's "exquisite and intricate" adaption make me feel it has some sort of sentient identity - " find the right host and go for it " in order to survive. Maybe they were Transylvanian bats en route to humans? 😃
I share your concern about your wacky immune system or lack there of....I hope you are back to the IVIG on a regular basis. I have no immune system of my very own and I rely on the IVIG I receive every 4 weeks. It has taken nearly 3 years to get my IgG’s into a low normal range and that is good, however, I have no IgD, IgA is <3 and the IgM is <5. I have read that during this Covid period that those receiving IVIG do better and have a lesser case and the thought is that as more people developed antibodies and donate blood we just may benefit there as well. We can only hope! I am doing GREAT and I am being very cautious. Hope you are hanging in there!
Thanks for posting this Jackie. It is understandable for those of us who don’t have your level of expertise/training. It reminds me of when I first met my CLL Specialist (this occurred after I had a less than optimal first line treatment experience at another institution with a general oncologist) he asked what do you know about SLL/CLL and why are you here? I rattled off some of the basics I learned here and then I said I’m here because this is a complex disease and you're an expert. He nodded approvingly and said something along the lines of it’s hard to put into words just how complex this disease is but I’ll do my best to simplify it for you and he has done just that over the past couple of years. The writer of this article also successfully translated this complex topic into something that is understood by the average person.
Couldn't agree more... Interesting article...Two weeks into Lockdown I started going out as a rational decision for me! I said "for me!" Since then I have continued, using trains and buses without the slightest issue. Everywhere I go, I see people NOT wearing masks. I have empirically demonstrated that the CLL Immune reaction is both in theory and practice, a gradation from completely useless to completely useful...BUT obviously don't recommend anyone here to follow my example. However I am living proof that some CLL patients don't need to shield at all, and on a CLL forum, that fact is possibly of interest to some. Apparently I am shielding far less than my doctors!!!!!
Jackie, thanks for posting. Excellent overall explanation of how our immune system works, with everything, not just the COVID virus. I actually understood most of the article.
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