This literature marketed report as described by the authors in the published article refers to a 6-year-old boy. The patient immunization status included vaccination with 4 doses of conjugated Hib vaccine at the recommended timing and dosing interval. (Date, dose, lot number not reported). On an unspecified date the 6 year old boy was brought to the emergency room with a 2-day history of sore throat, neck pain, tactile fever, and 1 episode of vomiting. Prior to the event onset it was reported that on an unknown date patient was vaccinated with 4 dose of conjugated Hib (manufacturer unknown) recommended timing and dose intervals. On physical examination, he was afebrile and well-appearing. He had an injected oropharynx without tonsillar hypertrophy or exudate. A group A streptococcus rapid antigen detection test was negative, and a throat culture was performed. In the emergency department, he was treated with given acetaminophen and ondansetron, tolerated oral intake, and was discharge to home with a diagnosis of viral pharyngitis. Four hours later the patient returned to emergency department with cough and respiratory distress. His mother reported that he developed a high-pitched sound when he breathed and that he felt like there was something stuck in his throat. He had not eaten food since leaving the emergency department and was able to tolerate liquids with difficulty. On examination, he had a heart rate of 166, a temperature of 37.1 degrees C, and a respiratory rate of 24. He was noted to have nasal flaring and accessory muscle use. On lung exam he had transmitted upper airway sounds. He had no stridor or wheezing. He received humidified oxygen, decadron 10 mg PO, and racemic epinephrine without improvement. A chest x-ray was normal. A lateral neck film was obtained. The patient's respiratory distress increased and he developed inspiratory and expiratory stridor. Albuterol and ATROVENT nebulizer treatments were given without improvement. Laboratory tests were drawn, including a complete blood count (revealing a white blood cell count of 23 300, 74% segmented neutrophils, 20% band forms, hemoglobin 12.9 g/dL, platelets 299 000), Basic Metabolic Panel (BMP), and blood culture and ENT was consulted. The attending radiologist review the lateral neck films and noted the enlargement of the epiglottis and thickening of the aryepiglottic folds. The patient received ceftriaxone and vancomycin, and he was emergently transferred to the operating room for direct laryngoscopy and intubation. In the operating room, a very swollen, beefy red epiglottis and swollen vocal cords were visualized. Cultures of the upper airway were obtained. He was intubated and transported to the pediatric intensive care unit for further management. The patient was diagnosed with epiglottitis. The patient was treated with steroids, ceftriaxone, and vancomycin initially. He remained intubated for 3 days as his airway swelling gradually decreased. On the third day of admission, sputum cultures grew Staphylococcus aureus and Haemophilus influenzae, type B (Hib). Blood cultures from admission also grew Hib, resistant only to ampicillin. Respiratory viral panel was negative. He was initially treated with intravenous ceftriaxone. Following consultation with the infectious disease team, the patient was discharged to home with an additional 7 days on cefdinir, for a total of a 14-day course of antibiotics. Further investigation into the patient's immunization status confirmed that the patient had received 4 doses of the conjugate Hib vaccine at the recommended timing and dosing intervals. Hib antibody titers drawn during his admission revealed inadequate response to these vaccines, with a Hib antibody titer of 0.6 micro-g/mL (<1.0 micro-g/mL is indicative of an antibody response that is not protective). Pneumococcal serology was sent and he was found to have several positive titers, suggesting that he responded well to other encapsulated organisms. He was discharge to home to follow-up with the infectious disease team as an outpatient for further immune workup. The outcome of event was considered as recovering. The event of epiglottitis was considered to be related to vaccination failure since the author stated that despite the success of vaccination programs in developed countries, cases of Hib epiglottitis still occur. Factors include failure of age-appropriate immunization, underimmunization (waning immunity in the absence of boosters), and vaccine failure. The conjugate Hib vaccine has proven to be very effective at decreasing the incidence of invasive Hib disease, with efficacy rates of 93% to 100% after 3 doses. Therefore, rare vaccine failures should prompt further investigation. Hib invasive disease is considered a true vaccine failure after obtaining lot numbers of the vaccines administered and investigating whether improper storage and administration of the vaccines has occurred. Additional information has been requested.