From the Guidelines
A patient who has been vaccinated for Haemophilus influenzae type b (Hib) can still contract the disease due to waning immunity, incomplete vaccination series, or infection with non-vaccine strains, and treatment typically involves prompt antibiotic therapy. When a vaccinated patient contracts Hib, the primary concern is to initiate effective treatment to prevent morbidity and mortality. The treatment options available for such patients include:
- Antibiotic therapy with a third-generation cephalosporin, such as ceftriaxone or cefotaxime, as the first line of treatment 1
- Alternative antibiotics, such as chloramphenicol or a fluoroquinolone, for patients with beta-lactam allergies
- Supportive care, including management of fever, maintaining hydration, and monitoring for complications
- Hospitalization, especially for invasive disease, to closely monitor the patient's condition and prevent secondary cases
- Prophylactic antibiotics, typically rifampin, for close contacts of the patient to prevent secondary cases, as recommended by guidelines such as the UK Joint Specialist Societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults 1. It is essential to note that vaccination does not guarantee complete protection against Hib, and breakthrough infections can occur. Therefore, prompt antibiotic therapy and supportive care are crucial to prevent morbidity and mortality in vaccinated patients who contract Hib. In addition to treatment, it is also important to investigate the cause of the breakthrough infection, such as waning immunity or infection with a non-vaccine strain, to determine the best course of action for the patient and their close contacts.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Contracting Hib Despite Vaccination
- A patient can still contract Haemophilus influenzae type b (Hib) despite being vaccinated due to primary vaccine failure, which can be caused by immunoglobulin (Ig) deficiency, particularly IgG2 subclass deficiency 2.
- Transient hypogammaglobulinemia of infancy (THI) is another possible cause of primary Hib vaccine failure, characterized by low IgG and IgA levels in the first three years of life 2.
Treatment Options
- Cefotaxime and ceftriaxone are effective in eliminating nasopharyngeal carriage of Hib, with Hib being eliminated within 2 days in 92% of patients and in all patients after the third day of antibiotic treatment 3.
- Third-generation cephalosporins, such as ceftriaxone and cefotaxime, are valid therapeutic alternatives to conventional drugs in the treatment of severe Hib infections, with high activity against Hib strains 4.
- High-dose ceftriaxone administration may be a considerable choice for the treatment of beta-lactamase-negative ampicillin-resistant (BLNAR) Hib meningitis, as seen in a case report where a patient recovered completely without any sequelae 5.
Vaccine Effectiveness
- Hib vaccines have a very favorable safety profile and have been found to be either cost-saving or cost-effective by many public health agencies, with a significant reduction in the incidence of Hib infections and their associated morbidity and mortality 6.
- Despite the effectiveness of Hib vaccines, many children remain unimmunized or underimmunized against Hib, particularly in limited-resource countries, highlighting the need for continued efforts to reduce the disease burden of Hib infections 6.