Effect of Infant Immunization on Procalcitonin Levels - A Pilot Study
Condition: Immunization
Study type: Observational

Summary: 
      Fever is a well-known side effect of immunizations. When a febrile infant presents to a
      healthcare site, such as an emergency room, a large number of tests are usually performed,
      which may include a procalcitonin (PCT) level. PCT is being increasingly recognized as an
      inflammatory marker suggestive of serious bacterial infection, and is being used in clinical
      practice in the workup for acute febrile illness. Based on an elevated PCT level, further
      testing may be done, antibiotics may be started, and the patient may get admitted to the
      hospital for observation before identifying the cause of the elevated PCT level. The
      investigators believe that immunizations can cause an increase in PCT levels in the absence
      of an acute infection. Thus, a finding of elevated procalcitonin in a recently immunized
      child may not have the same clinical implication as it does in other clinical scenarios. To
      investigate this, the investigators designed this pilot prospective study to compare PCT
      levels immediately before and forty-eight hours after the administration of routine infant
      immunizations. The investigators will enroll healthy infants presenting for their two, four,
      and six-month well child visits at FamilyCare - Children's Medicine Center and receiving
      routine immunizations as recommended by the Centers for Disease Control.
    

Detailed description: 
      This pilot study is a prospective study enrolling infants who are currently healthy, have no
      acute illness in preceding fourteen days, and were born full term that are presenting at
      FamilyCare - Children's Medicine Center (CMC) for their 2, 4, and 6-month well child visit
      that includes routine immunizations. Following informed consent, a blood sample will be
      obtained from enrolled infants for PCT testing prior to their routine, scheduled
      immunizations. The infants will return to CMC to have their PCT levels re-tested at 2 days
      post immunization. An infant will be included in the study for only one well child visit; if
      an infant presents for a subsequent well child visit falling within our sample visit age, the
      infant is not eligible for study re-enrollment. The parent/guardian will be contacted via
      telephone at week post second blood draw to determine if the infant has experienced symptoms
      or received medical care during that time period. The patient population targeted for this
      pilot study will be infants presenting to their pediatricians at FamilyCare - Children's
      Medicine Center for two, four, or six-month well child visits on a Monday, Tuesday, or
      Wednesday and receiving their vaccines as recommended by the 2014 CDC schedule.10 This is a
      pilot study, and therefore had no power analysis performed to calculate sample size. The
      investigators anticipate that there will be a high rate of patients not returning for the
      second blood draw, approximately 50%, based on prior patient experience of the investigators.
      To achieve the sample of at least 20 patients completing both blood draws and the phone
      interview, the investigators will enroll 45 patients.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The patient population targeted for this pilot study will be infants presenting to their
        pediatricians at FamilyCare - Children's Medicine Center for two, four, or six-month well
        child visits on a Monday, Tuesday, or Wednesday and receiving their vaccines as recommended
        by the 2014 CDC schedule.