Integrated Safety Profile of a New Approved, Fully Liquid DTaP5-HB-IPV-Hib Vaccine

A phase 4, open-label study to evaluate the safety and immunogenicity of DTaP5-HBV-IPV-Hib in children previously vaccinated with DTaP2-HBV-IPV-Hib or DTaP5-HBV-IPV-Hib (V419-016)

DTaP5-HBV-IPV-Hib (Vaxelis®) is a hexavalent combination vaccine (HV) indicated in infants and toddlers for the prevention of diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and invasive disease due to Haemophilus influenzae type b. Switching between HVs during the childhood vaccination series is sometimes necessary due to, for example, vaccine availability, health-care provider preference, and/or tender awards. The purpose of this study was to describe the safety, tolerability, and immunogenicity of a booster dose of Vaxelis® in participants who previously received a primary infant series of either DTaP2-HBV-IPV-Hib (Hexyon®) or Vaxelis®. Healthy participants approximately 11-13 months of age who previously received a two-dose primary series of Hexyon® (HHV group) or Vaxelis® (VVV group) all received a Vaxelis® booster dose. Immunogenicity was evaluated by measuring antibody levels to individual vaccine antigens approximately 30 days following booster vaccination. Safety was evaluated as the proportion of participants with adverse events (AEs). The proportions of participants with antibody-specific responses for antigens contained in both Vaxelis® and Hexyon® at 30 days post-toddler-booster vaccination with Vaxelis® were comparable between groups, and higher in the VVV group for Vaxelis® antigens PRN and FIM2/3. The overall proportions of participants with AEs were generally comparable between groups. Following a booster dose of Vaxelis®, immune responses were comparable between groups for all shared antigens, and higher in the VVV group for antigens found only in Vaxelis®. The booster was well tolerated in both groups. These data support the use of Vaxelis® as a booster in mixed HV regimens.

Safety evaluation of the DTaP5-IPV-Hib-HepB vaccine: a review

INTRODUCTION

The DTaP5-IPV-Hib-HepB vaccine is the most recently approved combination hexavalent vaccine. In Europe, it is licensed since 2016 for primary and booster vaccination in infants and toddlers above the age of 6 weeks to provide active immunization against diphtheria, tetanus, pertussis, poliomyelitis, invasive diseases caused by Haemophilus influenzae type b and hepatitis B. In the US, DTaP5-IPV-Hib-HepB is approved since 2018 in children 6 weeks through 4 years of age. Its safety profile has been extensively documented in infants and children born at term, and also data in preterm infants are made available.

AREAS COVERED

In this article, we conducted a safety evaluation of the DTaP5-IPV-Hib-HepB vaccine in infants and toddlers considering evidence from clinical trials and post-marketing use, also with regard to data on special populations e.g. preterm infants.

EXPERT OPINION

Based on the available data, the DTaP5-IPV-Hib-HepB vaccine has demonstrated a good safety profile, similar to that of other approved penta- and hexavalent vaccines. Rather, post-marketing data are limited and are frequently reported in combination with other hexavalent vaccines or are not adjusted for shares of vaccines use. Neither relevant interferences with other co-administered pediatric vaccines nor safety issues in premature infants have been shown.

Evolving pharmacovigilance requirements with novel vaccines and vaccine components

This paper explores the pipeline of new and upcoming vaccines as it relates to monitoring their safety. Compared with most currently available vaccines, that are constituted of live attenuated organisms or inactive products, future vaccines will also be based on new technologies. Several products that include such technologies are either already licensed or at an advanced stage of clinical development. Those include viral vectors, genetically attenuated live organisms, nucleic acid vaccines, novel adjuvants, increased number of antigens present in a single vaccine, novel mode of vaccine administration and thermostabilisation. The Global Advisory Committee on Vaccine Safety (GACVS) monitors novel vaccines, from the time they become available for large scale use. GACVS maintains their safety profile as evidence emerges from post-licensure surveillance and observational studies. Vaccines and vaccine formulations produced with novel technologies will have different safety profiles that will require adapting pharmacovigilance approaches. For example, GACVS now considers viral vector templates developed on the model proposed by Brighton Collaboration. The characteristics of those novel products will also have implications for the risk management plans (RMPs). Questions related to the duration of active monitoring for genetic material, presence of adventitious agents more easily detected with enhanced biological screening, or physiological mechanisms of novel adjuvants are all considerations that will belong to the preparation of RMPs. In addition to assessing those novel products and advising experts, GACVS will also consider how to more broadly communicate about risk assessment, so vaccine users can also benefit from the committee’s advice.

Protective immune responses against Haemophilus influenza type b elicited by a fully-liquid DTaP-IPV-Hib-HepB vaccine (VAXELIS™)

BACKGROUND

DTaP-IPV-Hib-HepB is a fully-liquid, hexavalent combination vaccine (Vaxelis™) approved for vaccination against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B, and invasive disease due to Haemophilus influenzae type b (Hib). Hib capsular polysaccharide, polyribosylribitol phosphate (PRP), is conjugated to Neisseria meningitidis outer membrane protein complex (OMPC). Safety and immunogenicity of DTaP-IPV-Hib-HepB were evaluated in 6 Phase III clinical studies including > 5,200 children. Studies included vaccination schedules in the United States (2, 4, 6 months of age) and Europe (2, 3, 4, 12 months of age and 2,4,11-12 months of age).

METHODS

Data pertaining to anti-PRP responses of DTaP-IPV-Hib-Hep B compared to control vaccines from 5 Phase III studies are summarized.

RESULTS

Post-infant series, the percentage of participants that achieved protective antibody thresholds for PRP (anti-PRP titer ≥ 0.15 μg/mL and ≥ 1.0 μg/mL, respectively) were higher in DTaP-IPV-Hib-HepB recipients compared to recipients who received control vaccines. A high level of protective responses (96.6% at ≥ 0.15 μg/mL [95% CI:94.8, 97.9%]; 72.9% at ≥ 1.0 μg/mL [95% CI:69.2,76.4%]) were seen post-dose 2 of the 2 + 1 vaccination schedule and met superiority criteria over comparator, p-value < 0.001. In the same schedule, prior to administration of the toddler dose (in the second year of life), anti-PRP titers were higher in DTaP-IPV-Hib-HepB recipients (91.4% at ≥ 0.15 μg/mL; 46.8% at ≥ 1.0 μg/mL) as compared to recipients who received control vaccines (63.4% at ≥ 0.15 μg/mL; 17.1% at ≥ 1.0 μg/mL). One-month post-toddler dose, high levels of anti-PRP titers were achieved in both DTaP-IPV-Hib-HepB recipients (99.8% at ≥ 0.15 μg/mL; 96.6% at ≥ 1.0 μg/mL) and recipients who received control vaccines (99.5% at ≥ 0.15 μg/mL; 94.9% at ≥ 1.0 μg/mL).

CONCLUSIONS

These results support that DTaP-IPV-Hib-HepB induces a robust and sustained early Hib response. During the high-risk period for Hib disease after the infant vaccine and prior to the toddler dose; >90% of recipients maintained superior protective anti-PRP levels compared to control.

Technological approaches to streamline vaccination schedules, progressing towards single-dose vaccines

Vaccines represent the most successful medical intervention in history, with billions of lives saved. Although multiple doses of the same vaccine are typically required to reach an adequate level of protection, it would be advantageous to develop vaccines that induce protective immunity with fewer doses, ideally just one. Single-dose vaccines would be ideal to maximize vaccination coverage, help stakeholders to greatly reduce the costs associated with vaccination, and improve patient convenience. Here we describe past attempts to develop potent single dose vaccines and explore the reasons they failed. Then, we review key immunological mechanisms of the vaccine-specific immune responses, and how innovative technologies and approaches are guiding the preclinical and clinical development of potent single-dose vaccines. By modulating the spatio-temporal delivery of the vaccine components, by providing the appropriate stimuli to the innate immunity, and by designing better antigens, the new technologies and approaches leverage our current knowledge of the immune system and may synergize to enable the rational design of next-generation vaccination strategies. This review provides a rational perspective on the possible development of future single-dose vaccines.

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.

DTaP5-HBV-IPV-Hib pediatric hexavalent combination vaccine for use in children from 6 weeks through to 4 years of age

Introduction: Combination vaccines reduce the number of injections received by children, hence improving timeliness and coverage, and general acceptability among caregivers and health-care providers. The most recent hexavalent vaccine, DTaP5-HBV-IPV-Hib, has been also approved by the FDA.Areas covered: DTaP5-HBV-IPV-Hib has demonstrated good immunogenic and safety profiles, not inferior to other hexavalent vaccines already in use in the European market. Either (2p+1/3p+1) immunization schedules can be used with no significant differences. A low incidence of severe adverse events has been shown, similar to other combination vaccines. No issues have arisen when concomitantly administered with other vaccines.Expert opinion: The inclusion of two additional acellular pertussis components (FIM2 and FIM3) might yield better protection against the disease, but this remains to be clinically proven. The new vaccine uses Hib with unique protein carrier (PRP-OMPC) which elicits higher earlier immune response without compromising safety. Compliance with the immunization schedules is expected to increase by decreasing the number of injections needed in combined vaccines for a single visit. In addition, the improvements on the ease-of-use by its liquid-formulation, makes the vaccine preparation more acceptable for use in clinics and may reduce the odds of administration errors.