viral resistance

A Boston Globe article describes COVID-19 patients completing a course of Paxlovid – and then becoming ill again shortly thereafter. Is there something wrong with the drug? Is this something to worry about?
We've just gotten a whole bunch of good news – news we really needed – about finally getting the upper hand against COVID-19. Two vaccines, both more than 90% effective at protecting clinical trial participants against the disease, were announced just seven days apart. These numbers are well beyond expectations, but some critically important questions linger. Here they are. The answers will determine how successful the vaccines will be.