Just finished Vectors, that was much better. Felt like an actual plague was going on, and the setting of Terok Nor was great, seeing familiar faces and places but in a totally different context.
I did get the impression that not only was it a sequel to Infection but to another book as well. Kira was making constant references to something happening last year that required her to infiltrate the station. In fact Kira was probably the only let down in the book, and that was just I wanted to see more of her investigation on the planet.