Walker Books - The Quiet at the End of the World

How would if feel to be the last remaining human? Lowrie and Shen are the youngest people in the world after a virus caused global infertility. When the virus mutates to become even more deadly, the pair face a future entirely alone unless they can find a cure. But how can two teenagers succeed where the great scientists have failed? It feels as though there is no hope for humanity until they discover a secret that turns their entire world upside-down.