The specialized book "Epidemiología de la colonización nasofaríngea" by Ignacio Obando Santaella offers a comprehensive analysis of the role of Streptococcus pneumoniae as a common cause of respiratory infections. It highlights the importance of nasopharyngeal colonization as a crucial step in the development of pneumococcal infections, particularly in preschool children, who exhibit the highest colonization rates. The book examines the various risk factors that influence pneumococcal carriage and their impact on the epidemiology of pneumococcal disease across different age groups. Given the introduction of conjugate pneumococcal vaccines, understanding these dynamics is particularly relevant. Through the analysis of epidemiological surveillance studies, the book makes a valuable contribution to clarifying questions regarding serotypes and antibiotic resistance in the context of vaccine efficacy and the underlying molecular mechanisms.