Another question about H1N1 - this time, specifically about vaccination & immune systems

So, I’ve been reading up today on the latest swine flu threat, and something keeps bugging me…

It has been noted how the 1918 swine flu outbreak was most problematic for folks with strong immune systems, due to the fact that (if I understand correctly) most deaths were caused by an overly strong reaction by peoples’ immune systems when trying to battle the virus. It has also been noted that this latest virus is behaving an awful lot like the 1918 strain.

The way that current flu vaccines work (again, if I understand correctly) is by exposing recipients to dead or weakened samples of the virus, in order to prompt the immune system to learn how to fight them.

Taking these two things and putting them together creates in my mind a concern that vaccination for this latest virus could, in fact, prompt a given recipient to have a similar immune system overreaction to what was seen back in 1918. If that were true, then it seems like it would follow that rolling out a large-scale vaccination program would be a bad idea.

Now, that’s probably not the case - it seems far more likely that I’m somehow missing the boat. Probably, my concern is really caused by:

a) Unstrung getting his facts wrong
b) Unstrung missing a simple explanation of why his logic ain’t up to par in this case

I’ve done some Google searching, and some digging in past SD threads that mention the virus, but I’m still not getting it (again, probably due to either a) or b)). So, my question is, can someone set me straight here? As mentioned, probably something simple that I’m missing, but if someone could clue me in, I’d appreciate it…


Nothing in your message made any sense at all to me.

Of course vaccinations are still the preferred way to deal with these kinds of outbreaks. Your message is … circuitous and confusing.

It makes sense to me. The OP has heard that a major cause of death from the 1918 virus was too strong an immune response to it. He is wondering whether vaccination will, by increasing the strength of the immune response to the virus, make the virus more dangerous to the vaccinated person.

Just to clarify… Yes - Uncertain summarizes my question exactly.

While I’m clueless about the correct answer to this, can you supply a cite for where I can read about this?

Will do, although I am at a different computer than initially, and my internet connection here is, on a good day, craptacular.

The part about how vaccines work is the easiest to find - from the CDC’s Key Facts About Seasonal Flu Vaccine:

And from the CDC’s 2009 H1N1 Influenza Vaccine Q&A Page:

These lead me to believe that I had the story right on how the H1N1 vaccine works, at least. Bear with me for a bit - I’ll relocate the places where I found info on the 1918 pandemic as soon as possible…

Cutting through the special features of H1N1, with my semi-elderly, attacked-from-all-quarters, immune system I’m more likely to fall to one of the more-normal ones. Fresh, young virii I either find immunologically unimpressive or kicked the ass of 50 years ago.

ETA: If a repeat of the 1918 version came through, I’d expect it to kill me, but I don’t see it in H1N1.

The op refers to the speculation that some of the young adult mortality in the 1918 pandemic was due to something called a cytokine storm.

The op’s question is a good one and the answer is an interesting one in several parts.

First, the possibility that cytokine storm was responsible for the young adult mortality in 1918 is still speculative. There have been other explanations proposed as well.

(And those over 60 today are still moderately well protected from H1N1 based on exposure to a close enough virus over 50 years ago. That’s T-cell memory too.)

Still, the cytokine storm hypothesis is widely believed.

Second (see same link as above),

So vaccines used today raise antibody levels much more than they elevate the cytotoxic response. Although they do some.

Third, the cells that cause a cytokine storm in individuals who get it with influenza are not the T cells anyway. They are not cells that are primed by vaccination at all. They come from the inate response.

More on the way that system works here.

The point is that the inate response is not primed - it is generic. Vaccination does not make it stronger. If enough virus gets into the lungs in an individual with a strong inate response then a cytokine storm results. T cells, which do respond to previous infections and to vaccination (live nasal more than killed injectable however) do however get the viruses out of there faster - and help keep them from getting down onto the lungs in the first place.

So putting this all together - vaccinations produce a strong antibody response which helps reduce the risk of infection in the first place. If cytokine storms were indeed responsible for the excess young adult mortality in 1918, then it was triggered by cells that would have been unaffected by vaccination. The strengthening of the immune response to influenza due to the vaccine strengthens those parts of the system that prevent infection in the first place, prevent as many viruses from getting into the meat of the lungs if an infection does occur in the upper respiratory tract, and helps clear any viruses that do get into the lungs more effectively … all of which causes fewer of the buggers in the meat of the lungs for the fixed inate response to react to, thereby reducing the risk of the excess reaction that is the cytokine storm.

Yeah, more than you ever wanted to know. I know. Sorry.

No actually it was fascinating … and maybe should be turned into a report …

I am always fascinated about the issue, I have been a guinea pig for a testing lab for a while, and have gotten a number of flu shots that were experimental for various reasons so anything about influenza is interesting.

[last years was a sub-q variant instead of IM. I guess it was successful, no flu and i titred out ok]

Nope. As aruvqan said, fascinating and just what I wanted.

…and by “Bear with me for a bit”, I apparently meant “bear with me while I fall asleep at my computer and awaken several hours later, disoriented and drooling on my keyboard”. Luckily, in the meantime, DSeid came in and not only provided the reference info that I hadn’t, but also answered my question extremely well. Many thanks.

Count me in on that response too. Fascinating and informative.

Thank you. I am happy that you found it useful.

Just wanted to add to the chorus of “me too”-s. I got to the point where I was thinking about cytokine storms and gave up after that, so the concise, accessible explanation is appreciated.

I had just learned recently about cytokine storms and so this was definitely a good explanation.
If there was some way to nominate this thing to maybe be pushed to become a “Ask Ceceil” Question I Think it should be done, as it’s topical and interesting…