Comparison of Pattern of Lower Respiratory Tract Infection in Children Below 12 Years of Age With Their Immunization Status

Abstract

Background: Lower respiratory tract infections (LRTIs) remain one of the leading
causes of morbidity and mortality in children under 12 years. Immunization plays a
critical role in reducing the incidence and severity of LRTIs, yet incomplete or
delayed vaccination continues to affect outcomes, especially in resource-limited
settings.
Objective: To compare the clinical pattern, severity, and outcome of LRTIs among
fully immunized, partially immunized, and unimmunized children aged below 12
years.
Methods: This cross-sectional observational study included 180 children aged 1
month to 12 years admitted with LRTIs over a 1-year period. Immunization status
was verified using vaccination cards and caregiver history. Children were categorized
as fully, partially, or unimmunized per national immunization schedule. Clinical
features, duration of symptoms, severity (based on WHO classification), and
outcomes were compared.
Results: Among 180 children, 54.4% were fully immunized, 30.6% partially
immunized, and 15% unimmunized. Severe LRTI (e.g., pneumonia requiring oxygen
or ICU care) was significantly higher among unimmunized (74%) and partially
immunized (53%) compared to fully immunized children (19%) (p < 0.001).
Duration of hospital stay and complication rates were also higher in the
unimmunized group.
Conclusion: Incomplete or absent immunization is significantly associated with
increased severity and worse outcomes in pediatric LRTI cases. Strengthening
immunization coverage and parental awareness remains crucial in reducing the
burden of respiratory infections in children.