As the world wearies of trying to suppress the SARS-CoV-2 virus, many of us are wondering what the future will look like as we try to learn to live with it. Will it always have the capacity to make us so sick? Will our immune systems learn — and remember — how to cope with the new threat? Will vaccines be protective and long-lasting? “I don’t think we’ll be wearing masks in two to three years — for this virus,” said Vineet Menachery, a coronavirus researcher at the University of Texas Medical Branch in Galveston. Menachery laid out four possible scenarios for how humans might interact with SARS-2 over time — in other words, what kind of immunity we might expect. As Menachery sees it, the possibilities for the future when it comes to Covid-19 and human immunity break down as follows: sterilizing immunity, functional immunity, waning immunity, and lost immunity.