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Covid-19
SARS-CoV-2is following the evolutionary rule book
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The theory goes like this. At first, such a patient’s lack of natural immunity relaxes pressure on the virus, permitting the multiplication of mutations which would otherwise be
culled
by the immune system. However, treatment for chronic covid-19 often involves what is known as
convalescent plasma
.This is
serum
gathered from recovered covid patients, which is therefore rich in antibodies against sars-cov-2.As a therapy, that approach frequently works. But administering such a cocktail of antibodies applies a strong selection pressure to what is now a diverseviral population in the patient’s body. This, the cog-uk researchers reckon,may result in the success of mutational combinations which would not otherwise have seen the light of day. It is possible that b.1.1.7 is one of these.
cull
verb
to kill some animals of a group, usually the weakest ones,especially so that the size of the group does not increase too much
从〔一群动物中〕剔出，杀掉〔最弱者，以防止动物种群过多〕
convalescentplasma
康复血浆
se
·
rum
noun (plural serums or sera)
medicala liquid containing substances that fight infection orpoison, that is put into a sick person's blood
〔用于治疗的〕免疫血清
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