What is the Risk of Long Covid after Vaccination?

post by dawangy · 2021-05-31T19:32:45.760Z · LW · GW · 16 comments

This is a question post.

I received my 2nd shot of the Pfizer vaccine in the middle of April, but I still have some anxieties about some higher risk activities like indoor dining. Mostly, I'm worried about the possibility of long Covid.

This article, although it presents only one anecdote, does show that long Covid is at least possible after being fully vaccinated. As immunity evasive variants grow as a share of new infections, we might even expect this kind of occurrence to become more common as time goes on. A redditor claims that four vaccinated people he knows still ended up symptomatic. He could be lying, but maybe these variants are getting good at their job. 

I wish I could present better sources for my concerns but I'm afraid scrappy anecdotes and self reported data is really all we have to work with on this front right now. Or so I thought, until I ran into this preprint from the folks from JoinZOE and the Covid Symptom Study app. If you take a look at tables 8 and 9, you can see that the authors found no evidence for reduced incidence of symptoms lasting >28 days after vaccination in the younger age group (given that infection did occur, of course). The effect was significant in the older age group. I should add that this was self reported data and not a trial.

What are we to make of this? Do vaccines not protect us against long Covid in the way that we hoped they might? Of course, if we don't get infected, this isn't an issue. But if we are infected, then are we really at equal risk of developing long Covid as someone who was infected without vaccination? What other sources out there discuss this?

Answers

answer by pseudobison · 2021-07-03T14:13:38.370Z · LW(p) · GW(p)

Regarding the comments earlier in this thread suggesting that long Covid is largely misattributed depression, the symptom profile doesn't seem to bear this out. "At five weeks post-infection among Coronavirus Infection Survey respondents testing positive for COVID-19", quite a few are still experiencing symptoms that don't sound much like depression: 11% of individuals are still experiencing cough, 8% loss of taste, 8% loss of smell, 8% muscle pain. It also seems fairly clear from Figure 1a of the first(?) ZOE App long Covid study that a substantially higher proportion of those testing positive, vs. symptom-matched negative controls, have long symptom timecourses. You might take some comfort from the fact that the same figure shows that the proportion still experiencing symptoms continues to drop off markedly as additional time passes, though admittedly part of this might be down to some people eventually tiring of logging symptoms into the app.

That said: Speaking for myself, as someone who has been very cautious throughout the pandemic, after my second vaccination I suspect I will mostly go "back to normal", with some exceptions like continued mask-wearing in certain indoor public spaces subject to case rates. If Covid is going to be endemic at this point, as appears likely, the fact that I am as young as I will ever be, and will be recently fully vaccinated, gives me the best protection I will ever have. So after full vaccination, I suspect that when my immune system eventually gets to practice on "the real thing" - while there would be a small risk of a breakthrough infection (and a small risk of long COVID if one occurs), it seems there might be an equivalently small chance that the experience would increase my adaptive immunity such that I am in a better position if I catch a variant when I am older.

comment by Lukas_Gloor · 2021-07-03T20:43:58.346Z · LW(p) · GW(p)

Yeah, I think it doesn't reflect that well on Lesswrong that the other comment wasn't challenged more earlier. (E.g., since when do depressed people frequently lose their sense of smell??) It seems like the pendulum has swung so much from "we should be extremely cautious" to "people are overreacting" that it's starting to get unreasonable again. 

Also, the other answer here mentions this: 

"My model is that risk of getting seriously ill from COVID for someone in my demographic, after full vaccination, is zero for all practical purposes."

It really depends if we count Long Covid as "serious." Certainly seems serious if people's sense of self-worth is related to being able to do deep work, which you can mostly forget about with Long Covid for >12 months. Doubly vaccinated reduces risks of getting infected by 85%, and a 30% further reduction in Long Covid risk conditional on getting sick. That's a 10x reduction. But case numbers will be up more than 10x compared to large periods of 2020 (e.g., last summer). Therefore, it's not unreasonable to still be concerned and keep an eye on case numbers. 

answer by cata · 2021-05-31T22:17:04.600Z · LW(p) · GW(p)

In areas with a lot of vaccine penetration, case counts mostly are just going to be very low anyway; combined with the vaccine effectiveness against infection (~80-90% for mRNA vaccines) the probability of being infected will be negligible. For example, in my local area and given my demographics, my current best estimate is that I incur around 10 microcovids if I spend an hour indoors breathing right on another random person. (And I am using conservative numbers.) If that's not true in your area, it may well be true in a month or two.

The only way this is going to change is if a new variant comes around and mucks everything up (in which case the current studies won't be very informative.)

So for myself, I don't really care very much about answering this question right now.

comment by matejsuchy · 2021-06-01T02:18:10.103Z · LW(p) · GW(p)

As for "long covid" itself, my sense from talking with GPs is that it's mostly misattributed. There's the notorious study which showed that 2/3 of "long covid sufferers" had never been infected with C19 to begin with. It seems like it's just somewhat stronger-than-usual depression? All the risk factors for "long covid" seem to just be risk factors for depression.

On the matter of vaccine effectiveness, do we know what the numbers are for obese vs non-obese? Vaccines commonly don't work (well) for the obese, and given how overweight America is I wonder if this is depressing our numbers. Maybe it's like 98% for thin, 70% for overweight, 40% for morbidly obese or something like that?

Replies from: TurnTrout
comment by TurnTrout · 2021-06-02T16:02:25.098Z · LW(p) · GW(p)

There's the notorious study

Do you happen to have a link on hand?

Replies from: matejsuchy
comment by matejsuchy · 2021-06-02T19:50:07.086Z · LW(p) · GW(p)

I'm having trouble finding it. It was a survey done by David Putrino, it's mentioned here:
"By contrast, Putrino told me that in his survey of 1,400 long-haulers, two-thirds of those who have had antibody tests got negative results, even though their symptoms were consistent with COVID-19."

https://www.theatlantic.com/health/archive/2020/08/long-haulers-covid-19-recognition-support-groups-symptoms/615382/

Here is a more vague claim that seems to corroborate:

"Whereas some “long haulers” were found to be positive for SARS-CoV-2 RNA by RT-PCR at symptom onset, many did not fulfill the criteria for testing at the beginning of the pandemic, or tested negative at a time when respiratory symptoms had subsided. In addition, some “long haulers” did not have detectable antibodies to SARS-CoV-2 when the first serological test (Abbott) became available commercially.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/acn3.51350

 

If you look at the demographics of the sufferers, it's also somewhat suspect. Middle-aged well-to-do white women are massively over-represented. If it were a matter of over-active immunity you'd expect young women, and if it were a matter of a weak immunity getting overrun, you'd expect men. So, I'm not sure there's a good reason to suspect this population really would be the main sufferers of some legitimate long-term syndrome. OTOH, middle-aged white women have sky-high rates of depression.

Replies from: romeostevensit
comment by romeostevensit · 2021-06-02T20:14:41.077Z · LW(p) · GW(p)

I expect symptoms-consistent-with is broad enough to interact with a whole lot of stuff that is going on medically and culturally.

answer by Webstir · 2021-07-10T05:02:20.865Z · LW(p) · GW(p)

Seems this thread didn't get too far, but the evidence is pointing to reactivation of Epstein-Barre virus, ie. mono-nucleosis. If you've had mono, and you get covid, the chances seem high you will experience the mono like symptoms that have been dubbed long covid.

answer by Lukas_Gloor · 2021-07-03T20:30:51.496Z · LW(p) · GW(p)

30% lower than without vaccination – according to this study

The King’s College London/ZOE app collaboration is the largest longitudinal study of Covid symptoms in the world. Through our work, we have also examined the impact of vaccines on existing Covid-19 symptoms and the chance of developing Long Covid. While it is now widely known that double vaccination reduces the chance of getting infected by around 85 per cent, our work indicates that on top of this, vaccines also decrease the likelihood, if someone does get infected, of developing Long Covid by up to 30 per cent.

comment by pseudobison · 2021-07-03T21:56:08.756Z · LW(p) · GW(p)

Interesting... although that given that the report you link to is also about the ZOE research, and later seems to elaborate on what they mean by "up to" 30% as by saying that "even if a vaccinated individual goes on to contract Covid-19, that person’s chances of developing Long Covid are reduced by a further 30 per cent in the most at-risk age group", I wonder if this is just a slightly trumped-up way of stating the finding of a significant difference for the older age group alone in the preprint that OP already linked to. (The preprint states: "In the 60+ group, we found lower risk of symptoms lasting for more than 28 days (OR=0.72, 95%CI [0.51-1.00])".)

Replies from: max-dalton
comment by Max Dalton (max-dalton) · 2021-07-04T09:06:15.142Z · LW(p) · GW(p)

Yeah, If I'm reading the preprint correctly, the effect is insignificant in the under 60 group, and the overall odds ratio (of long covid conditional on infection, I think) is basically 1 (Figure 3). I'm not sure if this is about the study being underpowered, or if there's just no effect.

answer by gareth · 2021-05-31T19:46:58.790Z · LW(p) · GW(p)

The risk of death from covid after vaccination is near zero and this seems to be the case despite the variants. The vaccines all seem to be holding up well against the variants so your friends info is anecdote not data. If you’re still worried, keep wearing a mask, taking vitamin d and avoid large gatherings with people of unknown vaccination status. Apart from that, assuming you are living in an area with high vaccinations rates, just get on with your life. I would suggest that the risk to your mental health from continued isolation is higher than the risk of long covid.

comment by Neel Nanda (neel-nanda-1) · 2021-05-31T19:52:51.912Z · LW(p) · GW(p)

The risk of death from covid after vaccination is near zero and this seems to be the case despite the variants

This seems to be true, but this doesn't obviously imply the risk of long COVID is significantly decreased. As far as I'm aware, no one has really studied this. On priors I'd guess that vaccines help a bunch, but I don't understand what's going on here very well.

And I think this is an important question, long COVID seems to represent a lot of the harm of COVID to young people. If case rates in your area aren't that low, this definitely seems like a valid question to ask

Replies from: dawangy
comment by dawangy · 2021-05-31T20:08:11.976Z · LW(p) · GW(p)

My thoughts exactly. The only explanation (with the assumption that long Covid risk as a proportion of infections is actually lower in vaccinated individuals) that I can think of for why the JoinZOE paper may have found no significant effect in the reduction of long Covid as a proportion of cases (despite strong priors in favor of the opposite) is that perhaps people think of Covid less now and are more likely to drop off using the app if their symptoms don't persist than they were in say, December 2020 or January 2021. 

comment by dawangy · 2021-05-31T19:52:55.635Z · LW(p) · GW(p)

tbh, I would just ignore the anecdotes and focus on the JoinZOE paper preprint I linked in the post. I'm not worried about death from Covid as much as I am about the long haul symptoms. Death from Covid, as you have noted, is very rare among vaccinated individuals.

I still wear a mask almost everywhere I go. Only exception is for outdoor dining, where it's not possible. But hey, it's outdoors.

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comment by mingyuan · 2021-06-01T06:13:38.336Z · LW(p) · GW(p)

This doesn't address the exact question you asked, but I think it's important to say. (But it's 1 AM, so I'm not going to say it very well.)

(I'm largely using the general 'you' here rather than specifically calling out OP.)

COVID has put us in a state of fear that doesn't always respond appropriately to new data. It has always been true that you can get sick from being around other people. In fact, it's always been true that you can contract an as-yet-uncurable chronic disease from being around other people.

Is your post-vaccination risk of contracting long COVID significantly higher than that baseline risk? For that matter, what actions do you take every day that have a higher risk of death than contracting COVID does? Do you drive?

How much do you value activities like indoor dining, or concerts? If you didn't really care about going to restaurants or concerts in the first place, then sure, maybe it's costless to continue avoiding them. But if concerts are one of the things you enjoy most in the world, that's a magnitude of sacrifice to your fear that I don't think it makes sense to continue making post-vaccination.

My model is that risk of getting seriously ill from COVID for someone in my demographic, after full vaccination, is zero for all practical purposes. And my point here is, there have always been viscerally terrifying tail risks, like splitting your lip and having your face devoured by flesh-eating bacteria, but fear of flesh-eating bacteria doesn't control your life. You might get seriously injured in a car accident, but if you live somewhere where cars are an everyday necessity, you still drive.

So yes, maybe there is some not-exactly-zero probability of contracting COVID and becoming chronically ill post-vaccination. But going by all of the quantitative models I've internalized over the past 15 months, that probability is still very close to zero, and in any case nowhere near high enough that you should continue avoiding activities because of it. 

You're probably just avoiding activities because you've become so used to it, and now you're putting an unreasonably high burden of proof on the question of whether you should do things that used to seem normal to you. Like, you used to do certain things, then you stopped doing them because of COVID. Now the threat of COVID has been neutralized by the vaccine, so logically you should go back to your Before Times state. But your system 1 doesn't really get this, because it's settled into a new normal where every activity is by default unsafe until proven otherwise. Consider that probably, now that you're vaccinated, all activities are almost exactly as safe as they were before COVID.

As I said this was not particularly well-argued. But I hope I got across the general point.