Demonstration of durable hepatitis B immune memory in children vaccinated with a DTaP5-IPV-HepB-Hib infant-toddler series 7 to 8 years previously

Vaccination against hepatitis B (HepB) provides long-term protection against infection. This is despite a reduction in HepB surface antibody (anti-HBs) concentrations over time to levels below the well-accepted correlate of protection of ≥10 mIU/mL. Continued evidence of immune memory and protection despite declined anti-HBs concentrations can be demonstrated by HepB virus surface antigen challenge studies. Long-term immune memory and protection against HepB infection has not been demonstrated previously for the pediatric hexavalent vaccine DTaP5-IPV-HepB-Hib. This phase 3, multicenter, single-group, open-label challenge study (NCT04490499; EudraCT: 2020–000126–26) evaluated immune memory against HepB infection in children who had received DTaP5-IPV-HepB-Hib at 2, 4, and 11–12 months of age, or at 2, 3, 4, and 12 months of age. At age 8–9 years, they were each challenged with 5 μg of monovalent HepB vaccine. Anti-HBs levels were measured on pre-challenge day 1 and post-challenge day 30. At baseline, 45.4% (93 of 205) had anti-HBs levels ≥10 mIU/mL. On post-challenge day 30, 99.5% (201 of 202) had anti-HBs levels ≥10 mIU/mL, regardless of initial vaccination schedule. Post-challenge, geometric mean concentrations increased 71-fold over baseline and 96.0% of children had a ≥4-fold rise in anti-HBs concentrations with similar results across both dosing schedules. The challenge dose was well tolerated. The robust anti-HBs responses after a single 5-μg dose of HepB vaccine confirm the persistence of a HepB immune memory and demonstrate that DTaP5-IPV-HepB-Hib provides long-term protection against HepB.publishedVersionPeer reviewe

Safety and immunogenicity of a fully-liquid DTaP-IPV-Hib-HepB vaccine (Vaxelis™) in premature infants

Background: Immune immaturity may put premature infants at increased risk for infections. DTaP-IPV-Hib-HepB vaccine (Vaxelis™), a hexavalent vaccine studied in >6,800 children, has acceptable safety and immunogenicity profiles generally similar to control vaccines. Here we evaluate safety and immunogenicity of DTaP-IPV-Hib-HepB vaccine in premature infants. Methods: Premature infants were identified using prior medical conditions terms “premature baby/delivery” and/or “low birth weight baby”. Immunogenicity and safety data were summarized across one Phase II and four Phase III randomized, active-comparator-controlled clinical trials (Protocol 004 in Canada [Control: PENTACEL™]; Protocols 005 and 006 in the US [Control: PENTACEL™]; and Protocols 007 and 008 in the EU [Control: INFANRIX™ hexa]) and one Phase III clinical trial in the UK (PRI01C); no formal statistical comparisons were performed. Results: Overall, 160 infants were considered premature (DTaP-IPV-Hib-HepB = 111 Control = 49). The incidence of adverse events (AEs) for DTaP-IPV-Hib-HepB was comparable between overall and premature populations for all AEs days 1–15 postvaccination (Overall = 96.3%; Premature = 97.3%;), solicited injection-site AEs days 1–5 postvaccination (Overall = 84.1%; Premature = 75.5%), and solicited systemic AEs days 1–5 postvaccination (Overall = 93.7%; Premature = 94.5%). A high percentage of premature infants mounted protective immune responses to antigens contained in DTaP-IPV-Hib-HepB vaccine. Response rates in preterm infants for all antigens (80-99%) were in a similar range to all infants (80-99%) for both DTaP-IPV-Hib-HepB and control vaccines. Conclusions: DTaP-IPV-Hib-HepB vaccine has a low incidence of AEs, an acceptable safety profile, and elicited satisfactory immune responses in premature infants comparable to the overall study population. These findings support vaccination with DTaP-IPV-Hib-HepB vaccine in healthy premature infants

Safety and immunogenicity of a fully-liquid DTaP-IPV-Hib-HepB vaccine (Vaxelis™) in premature infants

Background: Immune immaturity may put premature infants at increased risk for infections. DTaP-IPV-Hib-HepB vaccine (Vaxelis™), a hexavalent vaccine studied in >6,800 children, has acceptable safety and immunogenicity profiles generally similar to control vaccines. Here we evaluate safety and immunogenicity of DTaP-IPV-Hib-HepB vaccine in premature infants. Methods: Premature infants were identified using prior medical conditions terms “premature baby/delivery” and/or “low birth weight baby”. Immunogenicity and safety data were summarized across one Phase II and four Phase III randomized, active-comparator-controlled clinical trials (Protocol 004 in Canada [Control: PENTACEL™]; Protocols 005 and 006 in the US [Control: PENTACEL™]; and Protocols 007 and 008 in the EU [Control: INFANRIX™ hexa]) and one Phase III clinical trial in the UK (PRI01C); no formal statistical comparisons were performed. Results: Overall, 160 infants were considered premature (DTaP-IPV-Hib-HepB = 111 Control = 49). The incidence of adverse events (AEs) for DTaP-IPV-Hib-HepB was comparable between overall and premature populations for all AEs days 1–15 postvaccination (Overall = 96.3%; Premature = 97.3%;), solicited injection-site AEs days 1–5 postvaccination (Overall = 84.1%; Premature = 75.5%), and solicited systemic AEs days 1–5 postvaccination (Overall = 93.7%; Premature = 94.5%). A high percentage of premature infants mounted protective immune responses to antigens contained in DTaP-IPV-Hib-HepB vaccine. Response rates in preterm infants for all antigens (80-99%) were in a similar range to all infants (80-99%) for both DTaP-IPV-Hib-HepB and control vaccines. Conclusions: DTaP-IPV-Hib-HepB vaccine has a low incidence of AEs, an acceptable safety profile, and elicited satisfactory immune responses in premature infants comparable to the overall study population. These findings support vaccination with DTaP-IPV-Hib-HepB vaccine in healthy premature infants

Endocarditis Caused by Culture-Negative Organisms Visible by Brown and Brenn Staining: Utility of PCR and DNA Sequencing for Diagnosis

Two cases of culture-negative endocarditis with cocci seen in valve vegetations are presented. The organisms were identified by molecular analysis using broad-range PCR primers complementary to the 16S rRNA gene, sequencing, and database search using BLAST software. The results and utility of this method are discussed