This is a prospective observational study assessing the clinical outcomes of children 2 to 59 months of age with both pneumonia and other co-morbidities presenting to a tertiary hospital outpatient setting in Malawi, Africa who are most at risk for mortality or have other complications and thus, are typically excluded from childhood pneumonia studies.

Inclusion Criteria:

• Male or female, 2 to 59 months of age.
• Excluded from enrollment in Innovative Treatment in Pneumonia (ITIP) 1 and ITIP2 clinical trials due to presence of any of the following:
• Hypoxia (SaO2 < 90% on room air, as assessed by a pulse oximeter).
• Severe respiratory distress (e.g., presence of grunting, nasal flaring, head nodding, or severe chest-indrawing).
• Severe malaria, classified by World Health Organization (WHO) guidelines on hospital care for children, including a positive malaria rapid antibody test result.
• Severe anemia, classified by WHO Integrated Management of Childhood Illness (IMCI) guidelines (i.e., severe palmar pallor) only if a positive malaria rapid antibody test result.
• severe acute malnutrition (SAM) (i.e., weight for height/length < -3 SD, mid-upper arm circumference (MUAC) <115, or edema).
• HIV-1 seropositivity or HIV-1 exposure, assessed as follows: An HIV-positive result upon rapid antibody testing.
• If a child is less than 24 months of age and has an HIV-negative result upon rapid antibody test documented from the past three months, the child's biological mother's HIV status will need to be assessed. If the mother is HIV-positive, the child will be included. If the mother does not have documentation of an HIV-negative test result from the past 3 months, she will be tested via rapid antibody testing to determine the child's eligibility for this study.
• Ability and willingness of child's caregiver to provide informed consent and to be available for follow-up (in the inpatient ward, returning to KCH for a scheduled study follow-up visit, and by phone) for the planned duration of the study.

Exclusion Criteria:

• Possible tuberculosis (coughing for more than 14 days).
• Stridor when calm.
• Severe anemia, classified by WHO IMCI guidelines (i.e., severe palmar pallor) if a negative malaria rapid antibody test result.
• Known allergy to penicillin or amoxicillin.
• Receipt of an antibiotic treatment in the 48 hours prior to the study based on caregiver's self-report and/or documentation in child's medical record.
• Living outside Lilongwe urban area, the study catchment area.
• Any medical or psychosocial condition or circumstance that, in the opinion of the investigators, would interfere with the conduct of the study or for which study participation might jeopardize the child's health.
• Participation in a clinical study of an investigational product within 12 weeks prior to enrollment or planning to begin participation during this study.
• Prior participation in ITIP1, ITIP2 or ITIP3 during a previous pneumonia diagnosis.

Children 2 to 59 months of age who present to Kamuzu Central Hospital or Bwaila District Hospital with fast-breathing pneumonia or chest-indrawing pneumonia and other co-morbidities, or severe pneumonia AND are excluded from ITIP1 and ITIP2