Alfayate Miguélez, SantiagoYague Guirao, GenovevaMenasalvas Ruíz, Ana ISánchez-Solís, ManuelGonzalez-Camacho, FernandoOrtíz Romero, M MarEspejo García, PilarGuerrero Gómez, CarmenIofrío de Arce, AntonioMoreno Parrado, LauraSánchez Andrada, Rosa MCascales Alcolea, EvaLorente García, SebastiánParedes Reyes, PedroCasquet Barceló, ÁngelaLópez Yepes, M LuisaVigueras Abellán, Juan JoséSanz Mateo, GonzaloDomenech Lucas, MirianMurcian Pneumococcal Study Group2021-01-262021-01-262020-12-28Vaccines (Basel). 2020 Dec 28;9(1):E14.2076-393Xhttp://hdl.handle.net/20.500.12105/11672Background: An epidemiological study of Streptococcus pneumoniae nasopharyngeal carriage in healthy children was carried out five years after the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13). Objectives: Study the impact of pediatric vaccination with PCV13, and other associated epidemiological factors on the status of nasopharyngeal carriage, the circulating pneumococcal serotypes, and the antibiotic susceptibility to more frequently used antibiotics. Methods: A multi-center study was carried out in Primary Health Care, which included 1821 healthy children aged 1 to 4 years old. All isolates were sent to the Spanish Pneumococcal Reference Laboratory for serotyping and antimicrobial susceptibility testing. Results: At least one dose of PCV13 had been received by 71.9% of children and carriage pneumococcal prevalence was 19.7%. The proportion of PCV13 serotypes was low (14.4%), with an observed predominance of non-vaccine serotypes, 23B, 11A, 10A, 35B/F, and 23A were the five most frequent. A high rate of resistance to penicillin, erythromycin, and trimethoprim sulfamethoxazole was found. Conclusions: A low proportion of PCV13 serotypes were detected, confirming the impact of pediatric vaccination for reducing the serotypes vaccine carriage. High resistance rates to clinically important antibiotics were observed.engVoRhttp://creativecommons.org/licenses/by/4.0/Streptococcus pneumoniae nasopharyngeal carriageAntimicrobial susceptibilityConjugate vaccinesAtribución 4.0 Internacional333792359110.3390/vaccines9010014Vaccinesopen access