Antigenuria after immunization with Haemophilus influenzae oligosaccharide CRM197 conjugate (HbOC) vaccine

Area of Science:

• Immunology
• Pediatrics
• Microbiology

Background:

• Haemophilus influenzae type b (Hib) conjugate vaccines, such as HbOC (HibTITER), are highly effective in preventing invasive Hib disease.
• Previous studies in older children indicated minimal or no antigenuria after HbOC vaccination.
• Understanding antigenuria patterns is important for accurate diagnosis and monitoring vaccine response.

Purpose of the Study:

• To investigate the presence and duration of Hib antigenuria in infants following HbOC vaccination.
• To compare antigenuria levels in infants with findings from previous studies in older children.
• To inform diagnostic interpretations of antigenuria in infants post-vaccination.

Main Methods:

• Urine samples were collected from 30 infants (6 weeks to 7 months) at various time points after receiving a standard 10-microgram dose of HbOC vaccine.
• Hib antigenuria was detected using a commercially available latex particle agglutination assay (Directigen).
• Urine samples were collected within 1 hour, 1-3 hours, 24 hours, and at 3, 6, and 9 days post-vaccination.

Main Results:

• Intense Hib antigenuria was detected in infants within 2-3 hours post-vaccination.
• Antigenuria persisted for up to 3 days in some infants, with less intense levels detectable for several days.
• This contrasts with previous studies in older children showing little to no antigenuria.

Conclusions:

• Infants exhibit significant Hib antigenuria for several days after receiving HbOC conjugate vaccine.
• Antigenuria following Hib vaccination could be misinterpreted as evidence of invasive Hib infection.
• Healthcare providers should be aware of this phenomenon to avoid misdiagnosis in infants.