AUTHOR=Silva Pedro H. , Vázquez Yaneisi , Campusano Camilo , Retamal-Díaz Angello , Lay Margarita K. , Muñoz Christian A. , González Pablo A. , Kalergis Alexis M. , Bueno Susan M. 

TITLE=Non-capsular based immunization approaches to prevent Streptococcus pneumoniae infection

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2022.949469

DOI=10.3389/fcimb.2022.949469

ISSN=2235-2988

ABSTRACT=<p><italic>Streptococcus pneumoniae</italic> is a Gram-positive bacterium and the leading cause of bacterial pneumonia in children and the elderly worldwide. Currently, two types of licensed vaccines are available to prevent the disease caused by this pathogen: the 23-valent pneumococcal polysaccharide-based vaccine and the 7-, 10, 13, 15 and 20-valent pneumococcal conjugate vaccine. However, these vaccines, composed of the principal capsular polysaccharide of leading serotypes of this bacterium, have some problems, such as high production costs and serotype-dependent effectiveness. These drawbacks have stimulated research initiatives into non-capsular-based vaccines in search of a universal vaccine against <italic>S. pneumoniae.</italic> In the last decades, several research groups have been developing various new vaccines against this bacterium based on recombinant proteins, live attenuated bacterium, inactivated whole-cell vaccines, and other newer platforms. Here, we review and discuss the status of non-capsular vaccines against <italic>S. pneumoniae</italic> and the future of these alternatives in a post-pandemic scenario.</p>