RESUMEN
OBJECTIVE@#To study the effect of pertussis vaccination on the clinical manifestations of infants and young children with pertussis.@*METHODS@#A retrospective analysis was performed to investigate the differences in clinical manifestations and peripheral blood cell levels between pertussis children with different pertussis vaccination status.@*RESULTS@#A total of 1 083 children with pertussisat at age of < 3 years were enrolled, with 551 children in the unvaccinated group and 532 in the vaccinated group. Of all the children, 392 had an age of onset of < 3 months (372 were unvaccinated and 20 were vaccinated) and 691 children had an age of onset of ≥ 3 months (179 were unvaccinated and 512 were vaccinated). Compared with the vaccinated group, the unvaccinated group had a longer length of hospital stay and a higher incidence rate of respiratory failure (@*CONCLUSIONS@#Pertussis vaccination can reduce the incidence of severe pneumonia and respiratory failure and alleviate the severity of respiratory complications in infants and young children with pertussis.