Lions and domestic cats have a common ancestor but lions don’t devolve to mostly harmless. Immunity to domestic cats (we can just physically dominate them) doesn’t give us any immunity to lions. Lions aren’t a pandemic scourge for other reasons.
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Interesting to consider the difference between a predator and a parasite. Small size and reproductive speed both matter. A lion is big enough that it can’t feed on you indefinitely keeping you alive. Let alone breed in you.
Hmm there are only 45 recognized species of coronavirus total, of which 7 infect humans. For rhino viruses, there are 160 for humans alone. Possibly because rhinoviruses are among the smallest RNA viruses and coronaviruses are among the largest? Makes them less stable maybe?
Sizes:
Rhinoviruses: 30nm
Flu viruses: 80-120nm
Coronaviruses: 120nm but can range from 50 to 200 at extremes
Smallpox: 300nm
Domestic cats, leopards, lions/tigers, cattle.
HIV is also 120nm range
Hmm large mammals are actually a bad comparison. Viruses are as much smaller than bacteria (up to 100x) as insects are smaller than us. So we should map bacteria to predatory mammals and viruses to insects to get a better sense of proportions.
Cholera = 2 μm = 2000nm
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After all some viruses, bacteriophages, infect bacteria. Sometimes making them worse. Apparently the CTXφ bacteriophage makes cholera more severe
en.wikipedia.org/wiki/CTXφ_bacteriophage
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Lol, we’re just a sideshow in the viruses vs bacteria war for the planet .
“It is estimated there are more than 10^31 bacteriophages on the planet, more than every other organism on Earth, including bacteria, combined.”
Wonder if there’s any home-grade experiments or observations you can do with harmless bacteria that don’t require an electron microscope and won’t bring the FBI down on you. Hobby virology should be a thing.
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Hmm
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Replying to @vgr
History for Coronas needn’t exactly repeat
One way natural selection works is an aggressive parasite puts high evolutionary pressure on hosts
It seems our innate immune system tackles most cold viruses well enough that our adaptive immune systems never train on even stable ones
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From first QT, sounds like most cold viruses don’t do enough damage to require adaptive immune response (specific antigens). I guess first response stuff like interferon works well enough?
Replying to
Yet Another N=1 “Hugely Significant” Finding—
I heard today (TWIV 673) That Trump had NO COVID antibodies prior to receiving (on day 7?) REGN-COV2 antibody cocktail
I am NOT an expert immunologist but it *seems* adaptive immunity is not guaranteed v COVID


