Validity of self-reported pneumococcal vaccination status in the elderly in Spain

José María Bayas, Conchita Izquierdo, Laura Ruiz, Xavier Sintes, Dolores Sousa, José Miguel Celorrio, Wenceslao Varona, Jordi Carratalà, Manel Nebot, Joan Batalla, Silvia Sugrañes, Adriana Manzur, Ángel Terren, Carmen García, Esperanza Clemente, Susana Rivera, Isabel Justo, Ana Arévalo, Lluís Salleras, Ángela Domínguez