Wikipedia:Reference desk/Archives/Science/2020 October 8

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October 8

Do different persons' immune system create the same anti-bodies?

Let say that 2 persons get the same pathogen. Does their immune system will create the same anti-bodies (given that they won't die)?--Exx8 (talk) 13:57, 8 October 2020 (UTC)

The fourth paragraph of Antibody answers your question in considerable detail.--Shantavira|^{feed me} 14:50, 8 October 2020 (UTC)

I do not see that it does. There is no discussion of different individuals. In a Vigenère cipher, there is a tremendous variety of encryption keys. Yet, if two cryptanalysts crack the same encrypted text, they will have found the same key to decrypt it – which is because only one key will do the job. The answer to the OP's question is "no" because in this case there can be many different antibodies for the same pathogen, and it is a matter of chance which among these many candidates an individual's immune system happens to find. They may even bind to the same antigen while not being the same; if they bind to different antigens on the same pathogen they are bound to be different.  --Lambiam 20:21, 8 October 2020 (UTC)

So that's a "no", if you can't be bothered to look it up. See Antibody#Immunoglobulin diversity for even more detail. Michael D. Turnbull (talk) 14:54, 8 October 2020 (UTC)

Commonly, even a single individual produces different antibodies against the same pathogen. That's because it's not just one cell at a time trying its antibody; different immune cells will come up with different antibodies. See also polyclonal antibodies. Icek~enwiki (talk) 11:18, 10 October 2020 (UTC)

Generally speaking the immune system doesn't create antibodies against a specific antigene except in a metaphorical sense, but every cell of the immune system generates at random its own antibody variant, some of which by chance will recognize some given antigene or part of it or several similar antigenes or parts of them. That said, the answer should be more a clear 'maybe' I think: there are some 3 x 10^11 possible variants of standard antibodies according to [1] (but only 3.5 × 10^6 according to [[2]]) while in every human body there are about 2 × 10^12 lymphocytes [[3]] so it seems to me not impossible for two lymphocytes in a person and for any two different persons on Earth to possess some identical antibodies. 2003:F5:6F11:9700:E535:8213:E93C:4006 (talk) 17:56, 10 October 2020 (UTC) Marco PB