The present application is generally directed to methods for identifying immunogens from organisms and pathogens, and in particular for identifying immunogens which when administered as vaccines elicit a cellular and/or humoral immune response. The present application is also directed to pneumococcal T-cell immunogens, and vaccine compositions comprising one or a combination of pneumococcal immunogens and methods for treating or preventing pneumococcal infections using the vaccines thereof. The present invention also encompasses use of the pneumococcal immunogens for diagnostic purposes to identify a subject with a pneumococcal infection.
