Impact of circulating SARS-CoV-2 variants on mRNA vaccine-induced immunity

i wonder how many people were asymptomatic and thus weren't even aware. maybe those long-covid symptoms get diagnosed as something else if there is no known previous infection.

I wouldn't be so cavalier in assuming that just because you don't die that everything is A-OK and you're 100% fine. Viral infections can do damage that isn't apparent until years later. For example, it's now well-established that HPV infection causes cervical cancer later in life, and HPV is basically symptom-free.

> hardly any 1-4 year olds have died

Yes. The risk of this is pretty miniscule I think.

> Of course, there's "long covid" and all the sort of long tail risks and concerns, but intuitively it feels like if the disease is not that deadly and dangerous when you're that young, there'd also be less risk of all these other side effects we're seeing, which tend to correlate, as far as I can tell, with how severe the disease was for the person in the first place.

Not so much. I'm in a facebook group for long covid sufferers (and anyone who is interested), and there are quite a few people saying their children are suffering from long covid symptoms (less severe in absolute terms compared to adults due to higher baseline energy in children, but still significantly affecting their lives).

I've heard +10% of people are getting long covid, and that it doesn't correlate strongly with the severity of the disease.

Overall I think it is a little tricky to judge with kids. One thing I would add that you may not have considered is that being vaccinated doesn't necessarily preclude gaining natural immunity in future.

> is it worth it to leave her unvaccinated against Covid, at least for now, in order to get some natural immunity?

I have wondered the same, but my uneducated conclusion is that sequencing is important. I want the first exposure to be controlled (e.g. vax) and not random in dosage, etc. So vax and then natural exposure is what I believe to be the ideal order.

Never getting COVID is best.

Hybrid immunity is next best (natural + vaccine).

Vaccine is second best for most cohorts, because it comes with fewer side effects and the side effects typically aren't as bad.

Natural immunity is strong, but for most cohorts is more likely to have side effects compared to a vaccine.

Furthermore, the risk of side effects from COVID are lower if you are vaccinated. Therefore, given that breakthrough cases are still possible, I would suggest vaccinating first, then if they get it they get it and at least you get hybrid immunity in an order that is less risky than natural immunity followed by a vaccine.

For children, all of this is murkier. Also, if the likelihood of you catching Covid is low enough, there's absolutely no point getting vaccinated.

Might I ask why do you not consider the reverse order of events?

Get the vaccine first and then natural immunity should a breakthrough infection occur. Seems like a much safer way to go about it.

The problem in my opinion is accumulating lung tissue damage over a lifetime. I

If you have one covid infection per year with long damage, your life expectancy and quality drops quite a bit, even if covid is not killing you. The damage may only be perceivable to athletes and in later years though.

I think that one argument that does hold some weight is that each new infection is an opportunity for a new mutation and a new variant. This variant could be milder or it could be worse (delta). So in that view, vaccinating young children reduces the risk for all of us of a new variant arising that is much more infectious or even escapes the natural or vaccine induced immunity.

All that being said, one reason I live HN is that this question can be asked in a respectful manner and hopefully garner reasonable and respectful responses. Any other site this would turn into a flame war in 0.2us

Immediate vaccination does not inhibit long term protection. If the vaccine efficacy wanes to a significant degree (which is not a given for each individual), then you are still in a better place than having never been vaccinated. The safest way to get covid is as a vaccinated person. Not the other way round. There is no "tak[ing] one for the team" here.

You want her to get infected first so she then has stronger protection... against getting infected again? Compared to having protection for the (potential) first infection (which would also extremely likely lead to a hybrid immunity afterwards, if it doesn't prevent an infection entirely)? I struggle to see the scenario where that's helpful.

> But if it's true that natural immunity + vaccination) is stronger than vaccination alone, is it worth it to leave her unvaccinated against Covid, at least for now, in order to get some natural immunity

No? If she does not get infected after vaccination the job is done. The goal is not 'theoretical maximum protection' the job is 'not getting sick'.

If she gets infected after vaccination (very possible), she will have less risk during infection and have improved protection after.

Vaccination first and then infection is definitely safer than the other way around.

Ofc the risk for young children is low either way, so going with the low risk of being unvaccinated might be something you are ok with.

But getting infected to get best protection against infection is kinda backwards.

Iceland, Sweden, Denmark and Finland have halted Moderna for young people, pending further investigation of side effects.

If your child is vaccinated - there is a lower chance she gets COVID-19 - the disease. And if she does get it - it will be milder. But she may not get it at all with the vaccine just because the immune system is trained to eliminate it upon entry. In the assumption that vaccine does not have any side effects, the strategy to vaccinate is strictly dominating in game theoretic sense.

Let alone the fact that she has much lesser chance of being the spreader.

There are severe complications possible post covid for children (MIS-C) which makes this a very risky thing to do.

I would not vaccinate my child with an mRNA vaccine unless the consequences of not doing so would negatively affect their lives (cannot attend school in person, prevented from extracurriculars, etc.). At the end of the day it is still an experimental treatment with unknown side effects one year out, but more so because getting sick and allowing their body's natural immune system to do its job is part and parcel of being human. I would not want my children growing up with immune systems that are dependent on man-made vaccines/treatments when the statistics undoubtedly bear out the fact that children's immune system are far and away more than capable of fighting off Covid-19.

Obviously the above all goes out the window if your child has chronic conditions like asthma, diabetes, or nervous system disorders that make them highly susceptible to complications from viral infections.

You're not alone. We sent our K and 1st grade children back to school this fall expecting them to get (possibly asymptomatic) COVID at some point during the year. We're actually counting our blessings that this hit while they're at an age when they are likely to get some natural immunity without serious health complications. My wife and I are vaccinated, so hopefully any household contagion would be / will be moderate.

My impulse is that you’re trading one thing where the long term side effects are not 100% known (mrna vaccine) for two things where the long term side effects are not 100% known (covid and the mrna vaccine), and that there’s substantially more reason to believe long covid is a thing than that there are long term side effects to the vaccine.

Bigger issue though is that there’s no way to know exactly how long natural immunity will be effective either, as we know it also can wane in regards to this coronavirus. Giving a child covid now may be pointless to the goal of giving stronger protection to a more problematic strain later, if the strain comes along after the natural immunity has faded.

Realistically though, given current stats, the only statically valid reason to get babies vaccinated is to help lower community spread. Whether that’s asking a baby to “take one for the team” or reasonable depends on how much of a risk you view the vaccine as to children given the current data. (My personal belief is that long covid is a marginally higher risk than vaccine side effects so there’s no reason not to also lower community spread, but there’s no reason to think the baby won’t be fine either way).

We'll be vaccinating our young kids as soon as FDA provides EUA. If it's approved then it's safer than doing nothing in their age group. The risks of infection with no vax, vaccinated infection, or reinfection ("natural immunity") are all tiny in kids; we're more interested in protecting the grownups they spend their time around.

One angle that I don't see discussed a lot is what parents will plan to do if ACIP doesn't recommend any SARS-CoV-2 vaccine for very young kids (i.e. not until they're 5+ or maybe even 12+). It's very possible they could find the tiny risks from vaccination outweigh the tiny risks from infection.

There could in principle be an interesting moral question. If vaccinating very young kids is almost but not quite harmless -- like it raises their risk of mortality from the equivalent of driving 100 road miles to driving 110 road miles -- but it dramatically reduces the risk that their adult caregivers will die, should they be vaccinated? If ACIP ends up looking at the data and saying that vaccinating the youngest kids is worse I don't think I'll be giving them a non-approved vaccine. I can see why people would do it, though; the magnitude of the risks could be similar to those incurred with air travel as a lap infant vs. being secured in a carseat.

Please don't take medical advice from HN.

When you look at small children data, mind that there are some very high risk children out there. "Data from the first 12 months of the pandemic in England shows 25 under-18s died from Covid. [...] Around 15 had life-limiting or underlying conditions, including 13 living with complex neuro-disabilities." Another example, on TWiV 811 Dr. Daniel Griffin stated that risk of hospitalization is 4x for children with Down syndrome.

Where I get unease is the fact that there is no long term data of vaccine safety and effectiveness, in spite of the constant barrage of officials implying the contrary. What is the best path for kids to grow up, have their own children and have to ask themselves the same question? Is the answer 25 booster shots, one each year? How do vaccines interact with long term immune system? What about variants that have not evolved yet? We don't know.

Some choose 'if it ain't broken, don't fix it'. Some choose to put their faith in vaccines, 'the vaccine definitely helps in the short term, and there are minuscule downsides'. Some Amish refuse the vaccine on principle. Given the limited information we have, not sure there is a guaranteed right answer.

https://www.bbc.com/news/health-57766717

https://www.microbe.tv/twiv/twiv-811

Please also consider:

    Multisystem inflammatory syndrome in children (MIS-C) was first identified in April 2020 by doctors at children’s hospitals in the United States and the United Kingdom. The condition has also been called pediatric inflammatory multisystem syndrome (PIMS). MIS-C is an illness that can occur after COVID-19 infection and affects mostly school-age children. While the syndrome is rare, it can be dangerous.

https://www.hopkinsmedicine.org/health/conditions-and-diseas...

>Is it worth it to leave her unvaccinated against Covid, at least for now, in order to get some natural immunity?

Isn't the point of immunity against COVID to prevent COVID? What's the logic of getting COVID to get immunity against COVID?

From 2020 to October 6th 2021, there were 58,167 deaths in the age group 0-17. 499 of those deaths are related to COVID-19. That's 0.86% (or: 99.99% of deaths happened due to other causes) [1]

The leading cause of deaths in this age group are accidents [2]. A lot of these accidents are preventable [3].

[1] https://www.cdc.gov/nchs/nvss/vsrr/covid_weekly/index.htm

[2] https://www.cdc.gov/nchs/fastats/child-health.htm

[3] https://www.nhs.uk/conditions/baby/first-aid-and-safety/safe...

But why not just take the vaccine? That way you reduce the number of bodies the disease can breed in and spread. That’s how you eradicate something.

Yes, and in that order (first infection, then vaccine).

Another study: https://www.nature.com/articles/s41586-021-04005-0?f

I think that's somewhat expected, and basically analogous to "defense in depth". The mRNA vaccines only code for the characteristic spike protein, but an actual infection can result in developing antibodies against multiple features on the surface of the virus. Both being better than either alone is reasonable result of that.

The problem with natural immunity is that it can be so variable. Some people would develop better immunity from being infected than they would from just the vaccine, but some would develop much weaker immunity from the infection.

Does "fare better" include the risk of the first infection? Otherwise it seems somewhat contrived.

It's also hard to actually compare those things because there's an enormous literal survivor bias here. The living population of previously infected people have already demonstrated the ability to survive COVID.

If you took those same people, and magically made them immunologically naive, they would fare better than a random sample.

The difficulty is that the immune system is not linear. I am far from being an expert, but terms like ADE and original antigenic sin are part of the literature. This is not to say which approach is better, it is only a caveat that thinking in additive terms is just an approximation.

There is substantial evidence that the vaccines make a first infection less dangerous and not really much evidence that they inhibit later immunity, so you might want to take a step back and reexamine things.