n****4
发帖数: 12553 | 1 据说有两种免疫系统，一种是本征性的，比如小朋友的，自动立即对所有外物进行排斥
。另一种叫适应性的，主要是成年人的，对特定环境特定异物进行排斥，需要训练，所
以反应慢。千老们来说说
The innate immune system is the first line of defense against pathogens.
Cells in that system respond immediately to foreign invaders. (The adaptive
immune system, by contrast, learns to recognize specific pathogens, but
takes longer to join the battle.) If the innate immune response is stronger
in children exposed to 2019 nCoV, they may fight off infection more readily
than adults, suffering only mild symptoms.
Other coronaviruses, including SARS and MERS, also show this pattern, said
Krys Johnson, an epidemiologist at the Temple University College of Public
Health.
"The case we're seeing with the [emerging] coronaviruses is not that the
children are not having any symptoms at all, they're actually having viral
pneumonia," Johnson told Live Science, referring to the presence of infected
fluid in the lungs. "But because their immune systems are so robust, it
doesn't lay them out the way it would as an adult."
Similarly, Johnson said, adults are 25 times more likely to die from
chickenpox than children are. And though influenza can be devastating for
infants, older children usually make it through with more ease than adults,
Johnson said. Seasonal flu death rates in adults are 10 times that of death
rates in children. |
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