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Keeping my DW on tamiflu after she fights it off? Seems strange to me, as I thought once you beat most flu viruses, the likely hood of reinfection is minimal. </p>
<p>I thought generally from an epidemiological standpoint, most viruses die off primarily because enough of the population has developed resistance (through successfully outliving the virus) that there are not enough hosts who can infect to prepetuate the bug successfully. After a while (years if not decades), that resistance fades and the virus can then spread more effectively.</p>