[HN Gopher] Bacteria hijack a meningeal neuroimmune axis to faci...
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       Bacteria hijack a meningeal neuroimmune axis to facilitate brain
       invasion
        
       Author : bookofjoe
       Score  : 104 points
       Date   : 2023-03-12 13:40 UTC (9 hours ago)
        
 (HTM) web link (www.nature.com)
 (TXT) w3m dump (www.nature.com)
        
       | bookofjoe wrote:
       | >Bacterial meningitis hits an immunosuppressive nerve
       | 
       | https://www.nature.com/articles/d41586-023-00540-0
        
       | ramraj07 wrote:
       | This brings up an important point many folks may not realize: our
       | immune system a robust multilayered, highly redundant response
       | against any normal bacterium or virus. Thus, Any pathogen that
       | currently still causes disease by definition has to code multiple
       | specialized workarounds that hack these immune responses.
       | 
       | And importantly, pathogens that cause fatal diseases are
       | typically not very old in evolutionary time scales, it's
       | generally considered to be a bad idea evolutionarily speaking to
       | kill hosts you infect, and most of these pathogens are considered
       | to be in the path towards evolving into more benign invaders of
       | their hosts.
        
         | hammock wrote:
         | Sometimes our immune systems don't work though. In that case we
         | need vaccines. Please don't forget that
        
           | ramraj07 wrote:
           | What's your point? I literally said any pathogen that causes
           | disease in us has to break our immune system first. Of course
           | we need vaccines to help fight those disease.
        
           | originalcopying wrote:
           | sometimes we read people saying dumb things on the internet.
           | in those cases we need censorship. please forget this.
        
           | nick__m wrote:
           | A vaccine works by stimulating the immune system with a
           | pathogen-like substance to produce a response that trains it.
           | Ergo, if the immune system doesn't work, a vaccine is
           | useless!
        
           | krisoft wrote:
           | > Sometimes our immune systems don't work though. In that
           | case we need vaccines.
           | 
           | Sorry, but that sounds a bit confused.
           | 
           | Vaccines bring information to the immune system to train it
           | to recognise something as a threat faster than it would
           | otherwise. Think of it as a "wanted dead or alive" poster.
           | The poster doesn't go out and kill the baddies on its own.
           | The poster is distributed to the sheriffs of the towns, so if
           | the baddie shows up they recognise it for what it is before
           | the baddie robs the bank. In this parallel the baddies are
           | the infectious material (virus, or bacteria), the sherrifs
           | are the immune system, and the poster is the vaccine.
           | 
           | If your immune system don't work, first of all that is very
           | bad, second you don't need a vaccine. Because it won't help
           | you! Same as sending wanted posters to a town with nobody who
           | could act on them wouldn't make the town more secure.
        
             | realjhol wrote:
             | The problem comes if a mimic of the baddies gets attached
             | to hostages e.g. spike proteins attached to heart muscle
             | tissue. In this case, the immune system will attack the
             | "baddies" causing harm to the heart muslcle tissue in the
             | cross-fire. Heart muscle tissue never regenerates, hence
             | the spike in Myocarditis cases.
        
               | Aardwolf wrote:
               | > Heart muscle tissue never regenerates
               | 
               | Given the importance of the heart, that seems like a
               | strange way that this has evolved, given that other
               | tissue does regenerate
        
               | realjhol wrote:
               | Hard to fix a machine that can never ever go offline.
        
           | realjhol wrote:
           | Sometimes, but other times e.g. COVID-19, our immune systems
           | work extremely well in all except the very elderly and obese.
        
             | hammock wrote:
             | I'm sorry you are a victim of deplorable disinformation.
             | The vaccines actually prime our immune system to fight the
             | infection, and Covid is killing children not just the
             | elderly and body positive
        
               | realjhol wrote:
               | The evidence is all out in the open now - there's really
               | no hiding from it any more.
               | 
               | In randomized control trials of the mRNA COVID-19
               | vaccines here in the UK, we now know the risk of serious
               | adverse effects was 12.5 per 10,000 vaccinated i.e. a ~1
               | in 800 change of serious adverse effects:
               | 
               | 22-Sep-22 https://pubmed.ncbi.nlm.nih.gov/36055877/
               | 
               | The UK government has now published its estimate of the
               | number of people needed to vaccinate to prevent a
               | COIVD-19 hospitalisation:
               | 
               | 25-Jan-2023 https://assets.publishing.service.gov.uk/gove
               | rnment/uploads/...
               | 
               | For example in the 20-29 year no-risk group, the number
               | needed to vaccinate to prevent one hopitalisation is
               | 168,200. To prevent one serious hospitalisation requiring
               | oxygen or ventilation you would need to vaccinate
               | 706,500.
               | 
               | Even in the at-risk group for 20-29 years, the numbers
               | are 7500 and 59,500 respectively.
               | 
               | In fact there was no group except for 70+ where the risk
               | of hospitalisation (not severe requiring oxygen), came
               | close to the risk associate with vaccine injury.
               | 
               | It's for this reason, that these mRNA vaccines are no
               | longer being offered by the NHS.
               | 
               | Look - I'm sorry you were lied to, but at some point
               | you've just go to hold your hands up and admit the truth
               | of the matter.
               | 
               | Edit: plenty of downvotes, but no refutation.
        
               | ramraj07 wrote:
               | Here's your refutation: many of these results confound
               | pre omicron Covid with omicron Covid - the former was
               | 10-100x deadlier, and totally warranted global mandating
               | of the vaccines even with the published SAR rates. After
               | omicron, it is absolutely true that the adverse reaction
               | rate from mRNA vaccines might not be worth the benefit of
               | avoiding the relatively less fatal omicron variant
               | diseases for young individuals.
               | 
               | I will agree that regulatory agencies and many pro
               | vaccine arguments are doing a disservice by not being
               | thorough about such distinctions. That doesn't mean the
               | choices made pre omicron were invalidated. The mRNA
               | vaccines did a great job and did them in time to protect
               | millions more lives from being lost.
        
               | notahacker wrote:
               | You're comparing apples with oranges.
               | 
               | The majority of the serious adverse effects reported in
               | the original trials the first paper rehashes (15.1
               | effects per 10000 above a 6.4 effect per 10000 placebo
               | baseline with some people reporting multiple effects,
               | after the authors stripped out SAE's where the placebo
               | group reported _worse_ outcomes...) did not involve
               | hospitalisation, never mind intubation.
               | 
               | And a significant proportion of COVID infections that do
               | _not_ require hospitalisation (i.e not counted in the NNV
               | metric) nevertheless involve serious adverse effects
               | including both those credibly associated with vaccine
               | side effects but more commonly in symptomatic COVID
               | patients (myocarditis) and those not thought to have any
               | association with the vaccine such as long term brain fog.
               | The vaccines were found to have a high efficacy at
               | reducing these types of symptomatic infections though....
               | 
               | More generally and unfortunately for the cranks, its
               | noticeable that excess deaths and hospitalisation peaks
               | follow COVID infection spikes, not the ramp up of
               | vaccinations, and have declined considerably since the
               | vaccination programmes began. It's almost like the
               | professionals know better than someone who thinks
               | influenza is a coronavirus...
        
               | MaxfordAndSons wrote:
               | Sorry this is ot, but I can't help but note: replacing
               | "obese" with "body positive" is a wildly Orwellian
               | linguistic move. They aren't remotely synonymous, nor do
               | the groups they actually denote fully overlap (not all
               | obese people are body positive, nor are all body positive
               | people obese).
        
               | groestl wrote:
               | It's so over the top that it actually registered as
               | cynism with me.
        
             | RobotToaster wrote:
             | It's kind of the opposite, the majority of deaths from
             | covid were due to cytokine storm, which is your immune
             | system working _too well_ , and producing too many
             | inflammatory cytokines.
        
             | ramraj07 wrote:
             | 1/1000 people are dead in the US. Much more in places like
             | in India. And yet here we are people still underplaying it.
             | It's amazing seeing rewriting of history right in front of
             | your eyes for sure.
        
               | realjhol wrote:
               | As I say, most of those are in extremely elderly or obese
               | category.
        
               | parasubvert wrote:
               | This is a misunderstanding of how statistics work, and
               | part of the lie that Covid is an old people and obese
               | person's problem. Not that you're directly making this
               | argument, but for posterity: It's not just their problem.
               | Unless you feel cardiology and oncology are also old and
               | fat people's problems, since they die more of cancer and
               | heart disease?
               | 
               | The extremely elderly and obese die of _all causes_
               | disproportionately. But Covid lowers life expectancy and
               | increases mortality of _all age groups_ starting around
               | age 30 even after all mitigating measures (vaccines,
               | masks, etc) are taken in to account.
               | 
               | The young lower their own life expectancy when they
               | betray an inter-generational commitment to the older
               | generations to take care of them. This won't be the last
               | pandemic, and the young won't always be young.
        
               | realjhol wrote:
               | We have no idea what the long term effects of COVID-19
               | infection will be, however there's no reason to think the
               | long-term impact will be any different from any other
               | coronavirus flu.
               | 
               | And given that the virus is endemic, and the vaccines
               | only provided fleeting protection (they're not even being
               | offered by the NHS here in the UK any more), we'll all
               | get it sooner or later. There's no choice about it.
               | Fortunately for the vast majority of people, COVID-19 is
               | a mild disease that they will recover from quickly.
        
               | parasubvert wrote:
               | You have no idea what you're talking about and are
               | spreading misinformation.
               | 
               | 1. SARS-CoV-2 is not influenza.
               | 
               | 2. Influenza is not a coronavirus.
               | 
               | 3. Influenza usually kills 300,000-500,000 people
               | annually
               | 
               | 4. Consensus estimates of excess deaths from COVID-19 are
               | 14 million over the two years of 2020-2021. 2022 isn't
               | looking great either.
               | 
               | 5. All developed countries _highly_ recommend the annual
               | Influenza vaccine even with its variable annual efficacy,
               | as a way of lowering the intensity and spread.
               | 
               | The same will likely continue in many countries for
               | COVID-19, where the recent Bivalent vaccines show reduced
               | but still significant effectiveness against the recent
               | variants of SARS-CoV-2.
               | 
               | 6. COVID-19 has raised all cause mortality and lowers
               | life expectancy across _all age groups_ starting before
               | middle age.
               | 
               | 7. The UK NHS continues to offer standard two dose and
               | 3rd shot booster COVID-19 vaccines (all mRNA now) for
               | children over aged 5 and adults. This has not stopped.
               | 
               | Beyond this, they've limited additional boosters to
               | seasonal programs for target populations that are at
               | greater risk. They had one in the Autumn of 2022 and is
               | staring a new one for Spring of 2023 for the
               | immunocompromised and elderly (75+). The UK also signed a
               | deal with Moderna to begin producing mRNA vaccines within
               | the UK by 2025.
               | 
               | The vast majority of the UK population have COVID
               | antibodies and are at far less risk than they were in
               | 2020, but this continues to be monitored and may require
               | broader seasonal vaccination campaigns if immunity wanes.
               | 
               | 8. As with any disease vector there always is a choice to
               | use mitigations such as masks in crowded indoor spaces,
               | vaccinations, etc. to lower the spread. This is something
               | other countries learned decades ago.
        
               | realjhol wrote:
               | > You have no idea what you're talking about and are
               | spreading misinformation.
               | 
               | I actually do know what I'm talking about.
               | 
               | > 1. SARS-CoV-2 is not influenza. > 2. Influenza is not a
               | coronavirus.
               | 
               | I know. It's a flu-like respiratory illness from a class
               | of illnesses that humans face every season.
               | 
               | > 5. All developed countries highly recommend the annual
               | Influenza vaccine even with its variable annual efficacy,
               | as a way of lowering the intensity and spread.
               | 
               | No they don't. The UK does not offer flu vaccine for
               | anyone except member of vulnerable groups, young children
               | or medical workers.
               | 
               | > 6. COVID-19 has raised all cause mortality and lowers
               | life expectancy across all age groups starting before
               | middle age.
               | 
               | The all cause mortality has risen. There's every
               | indication that this is due to the mRNA vaccines.
               | 
               | > Beyond this, they've limited additional boosters to
               | seasonal programs for target populations that are at
               | greater risk.
               | 
               | Any why are they doing that?
               | 
               | It's because the likelihood of hospitalisation due to a
               | vaccine injury (1 in 800) [1] is greater than the
               | liklihood of being spared from a hospitalisation due to
               | COVID [2] in every age category except 70+.
               | 
               | [1] https://pubmed.ncbi.nlm.nih.gov/36055877/ [2] https:/
               | /assets.publishing.service.gov.uk/government/uploads/...
               | 
               | > The vast majority of the UK population have COVID
               | antibodies and are at far less risk than they were in
               | 2020
               | 
               | The vast majority of the UK population were at minimal
               | risk of COVID to begin with. I myself recovered from it
               | in less than a day.
               | 
               | 8. As with any disease vector there always is a choice to
               | use mitigations such as masks in crowded indoor spaces,
               | vaccinations, etc. to lower the spread. This is something
               | other countries learned decades ago.
               | 
               | As the Danish mask study shows, the mask mandates were
               | nothing more than securiy theater. The vaccines only
               | offer fleeting protection of a few weeks, so it's not
               | possible to keep the population on a 3-monthly treadmill
               | of boosters.
               | 
               | > This is something other countries learned decades ago.
               | 
               | No the UK had a policy that explicitly recommended
               | against mask mandates - especially paper and cloth masks.
        
               | heretohelp3546 wrote:
               | Hiya, here to help. In reviewing the HN guidelines at the
               | bottom of the page I was reminded that my initial
               | reaction to your performance on this thread here today
               | was uncouth, to be avoided.
               | 
               | Instead I'll take the high road. For an account created
               | ten months ago it seems possible you haven't read the
               | guidelines for commenting. Maybe it will help you
               | understand a bit of why you've been downvoted on this
               | thread today.
               | 
               | https://news.ycombinator.com/newsguidelines.html
               | 
               | My two cents, your mind appears to be made up on this
               | topic. It shows. It also tips your hand as to what media
               | sources you likely consume beyond HN.
               | 
               | Please consider (beyond the emotional reactions
               | associated with this thread on this day) that you could
               | perhaps use some improvement on having constructive
               | discourse in this sort of forum. Chiming in because I
               | like this place and have been here since near the
               | beginning. I'd like to see discourse not devolve into
               | factionalism or whatever more appropriate word could take
               | it's place in this context.
        
               | bitL wrote:
               | > no reason to think the long-term impact will be any
               | different from any other coronavirus flu.
               | 
               | Long covid is real and seems to affect up to 5% of covid
               | patients. We have no clue what the risk will be with
               | repeated infections and 1.05^n is a pretty steep
               | exponential curve when viewed in decades.
        
               | realjhol wrote:
               | > We have no clue what the risk will be with repeated
               | infections and 1.05^n is a pretty steep exponential curve
               | when viewed in decades.
               | 
               | This is fantasy
        
               | bitL wrote:
               | Head over to /r/covidlonghaulers and read it yourself.
        
               | realjhol wrote:
               | There is zero evidence of the exponential growth you are
               | describing.
        
               | concordDance wrote:
               | > The young lower their own life expectancy when they
               | betray an inter-generational commitment to the older
               | generations to take care of them
               | 
               | I get what you're trying to say, but this isn't the
               | correct argument for it. Social precedent relies on
               | people not having any excuses that allow special-casing,
               | which obviously doesn't apply here.
        
               | jimbob45 wrote:
               | Doesn't the US have a population of 330 million? And I
               | think we're at a million dead from COVID? So 1 in 330,
               | right?
               | 
               | Of course, taking into account time, population turnover,
               | and tourists, the ratio may actually be closer to yours
               | depending on how we decide to design the metric.
        
         | groestl wrote:
         | > it's generally considered to be a bad idea evolutionarily
         | speaking to kill hosts you infect
         | 
         | That sound's like it's giving some kind of agency to the
         | pathogen ;) when in fact it's more like: everyone that's
         | severly infected isolates or dies, so the more harmless
         | variants of the pathogen can replicate faster.
        
           | kyleyeats wrote:
           | Prions are so hyper-intelligent that they've even hacked this
           | "the host dying kills you too" problem.
        
           | originalcopying wrote:
           | it's merely a different way to lay down the explanations.
           | 
           | it's not "in fact" like you say; you merely provide an
           | alternative way to understand what's going on and to describe
           | it.
           | 
           | it's incorrect to claim that either is wrong because of the
           | other.
           | 
           | in the end, we gotta learn to have multiple ways to explain
           | the same things and it's best to shift between these
           | 'theories' of what is going on as it serves our purposes.
           | It's stupid to have this alternatives "fighting each other";
           | see? I just have agency to the ways to conceptualize,
           | understand, and explain phenomena.
        
             | Silverback_VII wrote:
             | When it comes to viruses, I think it is important to
             | understand that they simply replicate because they can. The
             | virus has no interest in keeping you alive or killing you;
             | it just infects cells and that's it.
        
           | Waterluvian wrote:
           | It's just an abstraction used to ease the conversation. If a
           | disease is inclined to behave like X, that's just a shortcut
           | to say, "it's evolutionarily advantageous if the mutations
           | result in X behaviour."
        
         | fnordpiglet wrote:
         | Rabies is generally fatal and is not new or genetically novel,
         | and like the article linked, is a CNS infection that travels
         | the peripheral nervous system. First recorded case was 4000
         | years ago, suggesting it's likely ancient through pre-history.
        
           | pvaldes wrote:
           | Rabies most probably evolved from a virus from plants so is
           | very "alien" to animals. As long as can hide in their main
           | host, it does not care about killing everybody else (if
           | accidentally ends in the wrong place). This can be also and
           | advantage and selected by evolution in some cases ("enemy of
           | my host is my enemy" situations).
        
           | kevviiinn wrote:
           | AFAIK is also isn't super contagious, less opportunity for it
           | to evolve
        
             | fnordpiglet wrote:
             | It's super contagious in the reservoir species. But it's
             | not in humans. The point made above was about age if the
             | pathogen not infectiousness.
        
           | ramraj07 wrote:
           | Viruses like rabies are interesting because they are actually
           | not as serious in the species they evolved to infect; just
           | turns out they rapidly kill some other species (us) that they
           | don't care about.
           | 
           | Make no mistake, rabies virus also has multiple immune
           | evading mechanisms that are unluckily supercharged in humans.
        
             | fnordpiglet wrote:
             | Yeah I expect that's the case - the bubonic plague spread
             | via the reservoir fleas and rats, etc.
        
           | echelon wrote:
           | How many humans get rabies per year versus how many that get
           | influenza?
        
             | pvaldes wrote:
             | Is not really designed for surviving outside. Very long
             | filaments are fragile out of vascular systems.
        
             | fnordpiglet wrote:
             | I'm not sure that's relevant? I didn't see anything stated
             | about rates of infection. Absolutely if influenza were as
             | fatal as rabies we would be extinct. But we also wouldn't
             | be posting on hacker news about it either. The statement
             | was about longevity of the pathogen and fatality.
        
               | echelon wrote:
               | > Absolutely if influenza were as fatal as rabies we
               | would be extinct.
               | 
               | The chance that it would evolve to be as infectious would
               | be greatly reduced. They teach this in first semester
               | immunology.
        
               | unsupp0rted wrote:
               | Not necessarily. What would be reduced is the likelihood
               | of showing any symptoms while still being infectious.
        
           | RobotToaster wrote:
           | Tuberculosis is likewise at least 5000 years old, and kills
           | around 50% of those infected.
        
             | meindnoch wrote:
             | >Roughly one-quarter of the world's population has been
             | infected with M. tuberculosis, with new infections
             | occurring in about 1% of the population each year. However,
             | most infections with M. tuberculosis do not cause disease,
             | and 90-95% of infections remain asymptomatic.
             | 
             | https://en.wikipedia.org/wiki/Tuberculosis#Epidemiology
        
         | somewhereoutth wrote:
         | Pathogens will evolve to best survive and replicate - for
         | fitness. If a pathogen kills a patient quickly before much
         | chance of spread then yes they wouldn't be very fit and
         | mutations delaying death would be beneficial.
         | 
         | However this certainly does _not_ imply that all pathogens
         | evolve to become  'mild'. Killing the host (or permanently
         | incapacitating them) is not necessarily incompatible with
         | effective spread.
         | 
         | Indeed, we have _no_ strong evidence of a pathogen evolving to
         | become milder. We do have lots of examples of hard won
         | population immunity reducing the harmfulness of pathogens.
         | 
         | Unfortunately it has become a bit of a 'natural is best' trope
         | that viruses necessarily become weaker, but in fact nature will
         | quite happily slaughter us, and it is our artificial
         | interventions that keep us fit and healthy.
        
         | jfowief wrote:
         | > And importantly, pathogens that cause fatal diseases are
         | typically not very old in evolutionary time scales, it's
         | generally considered to be a bad idea evolutionarily speaking
         | to kill hosts you infect, and most of these pathogens are
         | considered to be in the path towards evolving into more benign
         | invaders of their hosts.
         | 
         | This isn't necessarily true.
         | https://abcnews.go.com/Health/debunking-idea-viruses-evolve-...
         | 
         | How sad that chatgpt does a better job than most of the
         | commenters here.
         | 
         | >> ChatGPT: There are a few issues with this:
         | 
         | The statement that "Any pathogen that currently still causes
         | disease by definition has to code multiple specialized
         | workarounds that hack these immune responses" is not entirely
         | accurate. While many pathogens have evolved strategies to evade
         | or suppress the immune system, not all pathogens rely on these
         | mechanisms to cause disease. Some pathogens may cause disease
         | by producing toxins, disrupting host tissues, or interfering
         | with cellular processes, without necessarily having to evade
         | the immune system.
         | 
         | The claim that "pathogens that cause fatal diseases are
         | typically not very old in evolutionary time scales" is not
         | necessarily true. While some pathogens that cause fatal
         | diseases may be relatively new, others have been around for a
         | long time and have co-evolved with their hosts. For example,
         | malaria is caused by a protozoan parasite that has been
         | infecting humans for millions of years.
         | 
         | The statement that "it's generally considered to be a bad idea
         | evolutionarily speaking to kill hosts you infect" is an
         | oversimplification. While it is generally true that pathogens
         | that kill their hosts too quickly may be less successful at
         | spreading to new hosts, this is not always the case. Some
         | pathogens may benefit from causing rapid, severe disease if it
         | increases the likelihood of transmission to new hosts.
         | 
         | The claim that "most of these pathogens are considered to be in
         | the path towards evolving into more benign invaders of their
         | hosts" is also not entirely accurate. While it is possible for
         | some pathogens to evolve to become less virulent over time,
         | this is not a universal trend, and many pathogens may continue
         | to cause severe disease for extended periods of time.
         | Additionally, the evolution of a pathogen is influenced by a
         | wide range of factors, including the host population, the
         | environment, and the selective pressures imposed by the immune
         | system.
        
           | ramraj07 wrote:
           | No single statement I made was absolute for a reason which is
           | that exceptions exist, and while what gpt wrote is quite
           | amazing you can see how you can't trust it yet. I'm not
           | communicating to an audience that's well versed in
           | immunology, but to one that's new to it. Exposing them to
           | some common ideas and thoughts of why biological systems are
           | the way they are to give them better understanding without
           | overloading them with the vagaries of biological variety.
           | 
           | The reply from the bot sounds more like the smug 1st year
           | graduate student sitting at the back of the lecture who
           | thinks they're smart because they made a technically correct
           | counter point. Technically correct yes, but you won no fans
           | here for sure.
        
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