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Re: Vaccinations

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On 2/8/2017 9:39 AM, David Brown wrote:
> On 08/02/17 15:09, bill.sloman@ieee.org wrote:
>> On Wednesday, February 8, 2017 at 9:22:25 PM UTC+11, Reinhardt Behm
>> wrote:
>>> AT Wednesday 08 February 2017 04:03, John Larkin wrote:
>>>
>>>> On Tue, 7 Feb 2017 11:30:09 -0800, dplatt@coop.radagast.org
>>>> (Dave Platt) wrote:
>>>>
>>>>> In article <6vji9c9ghhj3mhs9odbllotts8m76f0hk5@4ax.com>, John
>>>>> Larkin  <jjlarkin@highlandtechnology.com> wrote:
>>>>>
>>>>>> Most viruses are specific to one or a few species. So most
>>>>>> species are immune to most viruses. It would make sense that
>>>>>> sub-species, namely some individuals, would also be immune to
>>>>>> classes of viruses. That diversity keeps a species from being
>>>>>> wiped out by one nasty virus.
>>>>>
>>>>> Yes, that's entirely plausible.  There are plenty of viral
>>>>> diseases which hit some people quite hard (up to and including
>>>>> lethality), but other people either have only mild symptoms or
>>>>> are entirely asymptomatic.  In some cases the difference can be
>>>>> pinned down to the effect of a single gene - the virus is able
>>>>> to spread effectively only in people with one specific allele,
>>>>> and not in others.
>>>>>
>>>>>> I wonder why every critter isn't immune to all viruses.
>>>>>
>>>>> Immunity to viruses (and bacteria, and rickettsia, and
>>>>> parasites) is always a tradeoff.  The immune system has to
>>>>> distinguish between "self", "non-harmful not-self", and
>>>>> "harmful not-self" molecules... mounting an attack against the
>>>>> latter category, and accepting the other two.  This isn't an
>>>>> easy distinction, and there are plenty of ways that the balance
>>>>> can go wrong one way or the other.  If the body is *too* prone
>>>>> to react, you get allergies (e.g. to peanuts) which can be
>>>>> quickly fatal, and you can also get auto-immune diseases
>>>>> (lupus, rheumatoid arthritis, rheumatic fever, Hashimoto's,
>>>>> Type 1 diabetes).
>>>>>
>>>>> In most cases (as I understand it) the body can't predictively
>>>>> "guess" which sorts of antigens mean "BAD - KILL IT WITH
>>>>> FIRE!".  Instead, the body has to wait until an initial
>>>>> infection occurs... take note of the fact that cells are dying
>>>>> and that they're exhibiting antigen X in the process... and
>>>>> then start manufacturing antibodies against antigen X to (1)
>>>>> cure the disease and (2) react immediately if antigen X shows
>>>>> up again in the future.  Hence, vaccination:  dose the body
>>>>> with a harmless dose of antigen X, plus (in many cases)
>>>>> something to stimulate the "This is harmful, KILL!" immune
>>>>> reaction.
>>>>>
>>>>>> Are viruses so clever?
>>>>>
>>>>> As to viruses being "clever" - I think it's more accurate to
>>>>> say "sloppy".  The virus gene-replication process can be
>>>>> rather error-prone, and errors during replication cause some of
>>>>> the next generation of viruses to be significantly different
>>>>> than the previous.  As everywhere, most of these mutations are
>>>>> either damaging or neutral.  In some cases, the mutated virus
>>>>> has "changed its coat" (i.e. its antigenic structure) enough to
>>>>> avoid recognition by antibodies that were effective against the
>>>>> "old" virus.
>>>>>
>>>>>> Or do viruses have a useful function, like horizontal
>>>>>> transmission of genes? Evolution works way better if there
>>>>>> is horizontal transmission.
>>>>>
>>>>> As to horizontal gene transmission:  you betcha!  Virus
>>>>> transmission of antibiotic-resistance genes plays a significant
>>>>> role in the development of resistant strains of bacteria...
>>>>> it's not the only way bacteria exchange genes but it does
>>>>> happen.
>>>>>
>>>>> Closer to home: the human genome contains a great many
>>>>> sequences which are derived from retroviruses - by one estimate
>>>>> 5-9% of our DNA is these sort of viral "left-overs".  Although
>>>>> none of these HERVs are actually capable of independent
>>>>> replication (they're all badly damaged by genetic drift),
>>>>> several of the HERV-derived genes are still intact and active.
>>>>> There's reason to believe that we, as humans, might not exist
>>>>> if it were not for them: several of these HERVs play a role in
>>>>> the formation of the human (more generally, mammal) placenta.
>>>>>
>>>>> http://schaechter.asmblog.org/schaechter/2014/06/retroviruses-the-
>>>
>>>>>
> placenta-and-the-genomic-junk-drawer.html
>>>>
>>>> It is creepy to think that we are each a walking collection of
>>>> human cells, viruses, mites, bacteria, fungi, parasites,
>>>> symbiotes, jumbles of other critters' DNA and RNA and proteins.
>>>>
>>>> And clothing. Clothes are a major component of our evolution.
>>>
>>> By cells count you consist of more foreign than you own cells.
>>
>> That's mostly the bugs in your gut, and the original calculation
>> seems to have been done on the back of an envelope, and isn't any too
>> reliable.
>>
>
> A ratio of 10 to 1 of gut bacteria to human cells was the original
> estimate.  More refined estimates are lower, but it still outnumber
> human cells significantly.

I was very surprised when I first heard this, but it seems to depend on 
the fact that bacterial cells are much smaller than human cells. 
Otherwise I think we would be *very* aware of the huge number of foreign 
cells in our body.

-- 

Rick C

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Vaccinations Don Y <blockedofcourse@foo.invalid> - 2017-02-06 17:50 -0700
  Re: Vaccinations bill.sloman@ieee.org - 2017-02-06 16:55 -0800
    Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-06 21:26 -0500
  Re: Vaccinations Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 17:56 -0700
    Re: Vaccinations "dcaster@krl.org" <dcaster@krl.org> - 2017-02-06 17:01 -0800
    Re: Vaccinations Don Y <blockedofcourse@foo.invalid> - 2017-02-06 18:04 -0700
    Re: Vaccinations Sylvia Else <sylvia@not.at.this.address> - 2017-02-07 12:21 +1100
      Re: Vaccinations Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 18:57 -0700
        Re: Vaccinations Sylvia Else <sylvia@not.at.this.address> - 2017-02-07 13:17 +1100
          Re: Vaccinations Rheilly Phoull <rheilly@bigslong.com> - 2017-02-07 10:22 +0800
          Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-06 21:35 -0500
            Re: Vaccinations Sylvia Else <sylvia@not.at.this.address> - 2017-02-07 13:39 +1100
              Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-06 23:31 -0500
          Re: Vaccinations Martin Riddle <martin_ridd@verizon.net> - 2017-02-06 22:47 -0500
          Re: Vaccinations John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-06 20:46 -0800
            Re: Vaccinations bloggs.fredbloggs.fred@gmail.com - 2017-02-07 02:20 -0800
            Re: Vaccinations dplatt@coop.radagast.org (Dave Platt) - 2017-02-07 11:30 -0800
              Re: Vaccinations John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-07 12:03 -0800
                Re: Vaccinations Reinhardt Behm <rbehm@hushmail.com> - 2017-02-08 18:22 +0800
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-08 05:23 -0500
                Re: Vaccinations Reinhardt Behm <rbehm@hushmail.com> - 2017-02-08 18:39 +0800
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-08 06:12 -0800
                Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-08 15:38 +0100
                Re: Vaccinations M Philbrook <jamie_ka1lpa@charter.net> - 2017-02-09 19:27 -0500
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-09 16:59 -0800
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-08 06:09 -0800
                Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-08 15:39 +0100
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-08 17:05 -0500
        Re: Vaccinations Martin Riddle <martin_ridd@verizon.net> - 2017-02-06 22:45 -0500
        Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-07 08:21 +0000
    Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-07 08:19 +0000
      Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-07 04:20 -0500
        Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-07 09:42 +0000
    Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-07 17:57 +0000
      Re: Vaccinations Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-07 11:12 -0700
        Re: Vaccinations "tom" <tmiller11147@verizon.net> - 2017-02-07 15:43 -0500
          Re: Vaccinations krw@notreal.com - 2017-02-07 21:15 -0500
            Re: Vaccinations amdx <nojunk@knology.net> - 2017-02-08 07:46 -0600
              Re: Vaccinations krw@notreal.com - 2017-02-08 12:45 -0500
              Re: Vaccinations dplatt@coop.radagast.org (Dave Platt) - 2017-02-08 11:33 -0800
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-08 17:19 -0500
            Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-08 17:57 +0000
              Re: Vaccinations krw@notreal.com - 2017-02-08 13:16 -0500
                Re: Vaccinations Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-08 18:32 +0000
                Re: Vaccinations Don Y <blockedofcourse@foo.invalid> - 2017-02-08 12:09 -0700
        Re: Vaccinations John Devereux <john@devereux.me.uk> - 2017-02-07 21:08 +0000
          Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-08 12:45 +0100
            Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-08 18:00 +0000
              Re: Vaccinations krw@notreal.com - 2017-02-08 13:16 -0500
                Re: Vaccinations Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-08 11:28 -0700
                Re: Vaccinations krw@notreal.com - 2017-02-08 20:33 -0500
              Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-08 17:26 -0500
                Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-08 23:09 +0000
                Re: Vaccinations Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 15:33 -0800
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-08 15:42 -0800
                Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-08 23:43 +0000
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-08 20:56 -0500
                Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-09 10:58 +0100
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-09 05:35 -0500
                Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-09 12:54 +0100
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-09 07:20 -0500
                Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-09 13:38 +0000
                Re: Vaccinations David Brown <david.brown@hesbynett.no> - 2017-02-09 14:56 +0100
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-09 17:47 -0500
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-09 17:16 -0800
                Re: Vaccinations Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-02-09 16:40 +0000
                Re: Vaccinations amdx <nojunk@knology.net> - 2017-02-09 11:04 -0600
                Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-09 17:46 -0500
                Re: Vaccinations amdx <nojunk@knology.net> - 2017-02-09 09:15 -0600
                Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-10 16:36 +0000
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-10 16:41 -0800
          Re: Vaccinations John Larkin <jjlarkin@highlandtechnology.com> - 2017-02-08 09:12 -0800
            Re: Vaccinations Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 09:36 -0800
              Re: Vaccinations John Larkin <jjlarkinxyxy@highlandtechnology.com> - 2017-02-08 12:40 -0800
            Re: Vaccinations Don Y <blockedofcourse@foo.invalid> - 2017-02-08 11:51 -0700
            Re: Vaccinations John Devereux <john@devereux.me.uk> - 2017-02-09 15:02 +0000
              Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-09 17:46 -0500
                Re: Vaccinations Cursitor Doom <curd@notformail.com> - 2017-02-10 16:52 +0000
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-10 16:46 -0800
              Re: Vaccinations krw@notreal.com - 2017-02-09 21:12 -0500
                Re: Vaccinations bill.sloman@ieee.org - 2017-02-09 19:01 -0800
                Re: Vaccinations John Devereux <john@devereux.me.uk> - 2017-02-10 08:23 +0000
                Re: Vaccinations krw@notreal.com - 2017-02-10 12:23 -0500
                Re: Vaccinations John Devereux <john@devereux.me.uk> - 2017-02-10 18:09 +0000
      Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-07 16:31 -0500
  Re: Vaccinations artie <artie.m@gNOSPAMmail.com> - 2017-02-06 17:28 -0800
    Re: Vaccinations Don Y <blockedofcourse@foo.invalid> - 2017-02-06 19:11 -0700
      Re: Vaccinations rickman <gnuarm@gmail.com> - 2017-02-06 21:34 -0500
  Re: Vaccinations Frank Miles <fpm@u.washington.edu> - 2017-02-07 01:52 +0000

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