SAN DIEGO – Predictions at the International Conference on Antimicrobials and Chemotherapy and the International Congress of Chemotherapy (ICAAC/ICC) 2015 annual meeting tend to be of the dire sort, warning of a return to the pre-penicillin era. So it was a pleasant exception to listen to Glaxosmithkline plc’s Rino Rappuoli brim with optimism during his plenary talk on challenges and opportunities of vaccines.