New perspectives for hexavalent vaccines

A worldwide overview for hexavalent vaccines and a glimpse into Turkiye's perspective

The surge in recommended vaccinations for child's has spurred the development of combination vaccines, notably hexavalent vaccines, which provide multiple immunizations in a single dose. These vaccines offer various advantages, such as streamlining vaccination schedules, minimizing injection-related pain and exposure to preservatives, expanding vaccine coverage, and reducing administration costs. However, the intricate and expensive development of these vaccines presents substantial challenges, requiring increased investment and healthcare provider education to optimize their utilization and sustain high vaccination rates. Turkey, known for its robust vaccine coverage, strategic geographic location, and the influx of refugees, is at a critical juncture for integrating hexavalent vaccines into national programs. This transition is especially relevant given the rising vaccine hesitancy and the potential resurgence of vaccine-preventable diseases. This review assesses the deployment of hexavalent vaccines, examining their benefits and challenges through clinical trials and global experiences, with a specific emphasis on Turkiye's public health context.

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.

Acceptance and willingness to pay for DTaP-HBV-IPV-Hib hexavalent vaccine among parents: A cross-sectional survey in China

DTaP-HBV-IPV-Hib hexavalent vaccine has been used in high-income countries for many years to prevent diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and invasive Haemophilus influenzae type b disease. Currently, no hexavalent vaccines have been approved for use in China. Evidence of parental acceptance and interest in hexavalent vaccines can help policy makers and manufacturers make decisions about entering the vaccine market and the immunization program in China. We measured parental acceptance and willingness-to-pay (WTP) for a hexavalent vaccine to provide such evidence. We conducted a cross-sectional survey of children's caregivers in 16 vaccination clinics in seven cities in China and obtained information on socio-demographics, knowledge of disease, confidence in vaccines, previous vaccination experience, and acceptance of and WTP for hexavalent vaccine. Multivariate logistic regression was used to determine factors influencing acceptance, and multivariate tobit regression was used to identify factors impacting WTP. Between April 28 and June 30, 2023, a total of 581 parents of children aged 0-6 years participated in the survey; 435 (74.87%, 95% CI:71.3%-78.4%) parents indicated acceptance of hexavalent vaccine. Residence location, parents' education level, experience paying for vaccination, and disease knowledge scores were key factors affecting parents' choices for vaccination. Mean (SD) and median (IQR) willingness to pay for full 4-dose course vaccination were 2266.66 (1177.1) CNY and 2400 (1600-2800) CNY. Children's age (p < .001), parents' education level (p = .024), and perceived price barriers (p < .001) were significantly associated with WTP. Parents have high acceptance and willingness to pay for hexavalent vaccine. The less money parents have to pay out of pocket, the more willing they can be to accept the vaccine. Therefore, acceptance may increase even further if the vaccine is covered by medical insurance, provided free of charge by the government, or if its price is reduced. Our results provide reference for optimizing and adjusting immunization strategies in China.

Preferences of healthcare providers in Switzerland for attributes of pediatric hexavalent vaccines: a discrete-choice experiment

OBJECTIVE

To understand the preferences of healthcare providers (HCPs) in Switzerland for pediatric hexavalent vaccine attributes.

METHODS

A discrete-choice experiment included a series of choices between 2 hypothetical pediatric hexavalent vaccines with varying attributes: device type (including preparation time and risk of dosage errors), proportion of infants seroprotected against Haemophilus influenzae type b (Hib) at 11-12 months (pre-booster), packaging size, years on the market, and the thermostability at room temperature. Odds ratios (ORs) and conditional relative attribute importance (CRAI) were calculated using random-parameters logit.

RESULTS

HCPs (150 pediatricians and 40 nursing staff) in Switzerland were unlikely to choose a vaccine conferring 50% (OR 0.00; 95% CI 0.00-0.00) or 70% (OR 0.01; 95% CI 0.00-0.01) of infants with Hib seroprotection at 11-12 months (pre-booster) compared with a vaccine conferring 90% seroprotection. The odds of choosing a vaccine available on the market for more than 3 years were nearly 5 times the odds of choosing a vaccine available on the market for less than 1 year (OR 4.76; 95% CI 1.87-7.65). The odds of choosing a vaccine in a prefilled syringe were nearly 3 times the odds of choosing a reconstituted vaccine (OR 2.77; 95% CI 1.39-4.15), and the odds of choosing a vaccine with a smaller package size were nearly 2 times the odds of choosing a vaccine with larger package size (OR 1.89; 95% CI 1.23-2.55). HCPs were equally likely to choose vaccines that can stay at room temperature for 6 versus 3 days (OR 1.07; 95% CI 0.73-1.42). According to CRAI, the most important attribute was Hib seroprotection, followed by years on the market, device type, and packaging size.

CONCLUSION

Hib seroprotection at 11-12 months was the most important hexavalent vaccine attribute to HCPs in this study.

Penta- and hexavalent vaccination of extremely and very-to-moderate preterm infants born at less than 34 weeks and/or under 1500 g: A systematic literature review

Debate regarding vaccinating high-risk infants with penta- and hexavalent vaccines persists, despite their good immunogenicity and acceptable safety profile in healthy full-term infants. We report the findings of a systematic literature search that aimed to present data on the immunogenicity, efficacy, effectiveness, safety, impact, compliance and completion of penta- and hexavalent vaccination in high-risk infants, including premature newborns. Data from the 14 studies included in the review showed that the immunogenicity and the safety profile of penta- and hexavalent vaccines in preterm infants was generally similar to those seen in full-term infants, with the exception of an increase in cardiorespiratory adverse events such as apnea, bradycardia and desaturation following vaccination in preterm infants. Despite recommendations of vaccinating preterm infants according to their actual age, and the relatively high completion rate of the primary immunization schedule, vaccination was often delayed, increasing the vulnerability of this high-risk population to vaccine-preventable diseases.

Cost minimization analysis of a hexavalent vaccine in Argentina

BACKGROUND

Argentina currently uses a pentavalent vaccine containing diphtheria, tetanus, pertussis (whole cell), Haemophilus influenza type b and hepatitis B antigens, administered concomitantly with the inactivated polio vaccine (IPV) (DTwP-Hib-HB plus IPV) in its childhood vaccination schedule. However, hexavalent vaccines containing acellular pertussis antigens (DTaP-Hib-HB-IPV) and providing protection against the same diseases are also licensed, but are only available with a private prescription or for high-risk pre-term infants in the public health program. We analyzed the cost of switching from the current schedule to the alternative schedule with the hexavalent vaccine in Argentina, assuming similar levels of effectiveness.

METHODS

The study population was infants ≤ 1 year of age born in Argentina from 2015 to 2019. The analysis considered adverse events, programmatic, logistic, and vaccine costs of both schemes from the societal perspective. The societal costs were disaggregated to summarize costs incurred in the public sector and with vaccination pre-term infants in the public sector. Costs were expressed in 2021 US Dollars (US$).

RESULTS

Although the cost of vaccines with the alternative scheme would be US$39.8 million (M) more than with the current scheme, these additional costs are in large part offset by fewer adverse event-associated costs and lower programmatic costs such that the overall cost of the alternative scheme would only be an additional US$3.6 M from the societal perspective. The additional cost associated with switching to the alternative scheme in the public sector and with the vaccination of pre-term infants in the public sector would be US$2.1 M and US$84,023, respectively.

CONCLUSIONS

The switch to an alternative scheme with the hexavalent vaccine in Argentina would result in marginally higher vaccine costs, which are mostly offset by the lower costs associated with improved logistics, fewer separate vaccines, and a reduction in adverse events.

Exploring the optimal vaccination strategy against hepatitis B virus in childhood (Review)

Vaccination against hepatitis B virus (HBV) remains the most effective strategy against HBV infection in humans. The present review summarized the optimal vaccination strategies against HBV in childhood. The following points are discussed: i) When and how the first HBV vaccines were developed; ii) the dosages, schedules and injection routes that are used for HBV vaccination; iii) the contraindications for HBV vaccination in the general paediatric population; iv) the challenges with the use of multivalent vaccines; v) the long-term immunogenicity and duration of protection against HBV; vi) the use of selective HBV vaccination and the hepatitis B immune globulin strategy in HBV-exposed infants; and vii) the effectiveness of the current HBV vaccination schemes. The present review is based on a Paediatric Virology Study Group (PVSG) webinar performed in the context of the 8th Workshop on Paediatric Virology.

Immunogenicity and Safety of a Hexavalent DTwP-IPV-HB-PRP~T Vaccine Versus Separate DTwP-HB-PRP~T, bOPV, and IPV Vaccines Administered at 2, 4, 6 Months of Age Concomitantly With Rotavirus and Pneumococcal Conjugate Vaccines in Healthy Infants in Thailand

BACKGROUND

This study investigated the immunogenicity and safety of a fully liquid, hexavalent, diphtheria (D)-tetanus (T)-whole-cell pertussis (wP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b (PRP-T) vaccine compared to licensed DTwP-HB-PRP~T, IPV, and bivalent oral poliovirus (bOPV) vaccines following co-administration with other pediatric vaccines [pneumococcal conjugate vaccine (PCV13) and rotavirus vaccine].

METHODS

Phase III, randomized, open-label study in Thailand. Healthy infants received DTwP-IPV-HB-PRP~T at 2, 4 and 6 months of age (N = 228), or DTwP-HB-PRP~T and bOPV (2, 4 and 6 months of age) and IPV (4 months of age) (N = 231). All participants received PCV13 (2, 4 and 6 months of age) and rotavirus vaccine (2 and 4 months of age). Immunogenicity for all antigens was assessed using validated assays, and noninferiority post-third dose was evaluated for anti-D, anti-T, anti-pertussis [anti-pertussis toxin (anti-PT) and anti-fimbriae 2/3 (anti-FIM)], anti-polio 1, 2, 3, anti-HB, and anti-PRP~T. Safety was assessed using parental reports.

RESULTS

Noninferiority was demonstrated for each antigen, and overall noninferiority of DTwP-IPV-HB-PRP~T versus DTwP-HB-PRP~T+bOPV+IPV was concluded. Similarity in each group was observed for the GMC ratio for antirotavirus antibodies (20.9 and 17.3, respectively) and anti-PCV13 antibodies (range: 8.46-32.6 and 7.53-33.1, respectively). Two serious adverse events were related to DTwP-IPV-HB-PRP~T (febrile convulsion and acute febrile illness) and 1 was related to DTwP-HB-PRP~T+bOPV+IPV (febrile seizure), but overall there were no safety concerns with similar rates of participants experiencing solicited (99.1% and 98.3%) and unsolicited (19.3% and 19.5%) adverse events in each group.

CONCLUSIONS

This study confirmed the suitability of DTwP-IPV-HB-PRP~T primary series vaccination in combination with rotavirus and PCV13 vaccines.

Estimating the Total Societal Cost of a Hexavalent Vaccine versus a Pentavalent Vaccine with Hepatitis B in South Korea

In South Korea, the ready-to-use hexavalent vaccine (against diphtheria, tetanus, pertussis, poliovirus, Haemophilus influenzae type b, and hepatitis B) is not listed despite its facility of no need to reconstitute. It, therefore, has the potential to augment the efficiency of prevention against the six infectious diseases, and it may reduce vaccine-related errors of reconstitution when compared with the currently used vaccination scheme of the pentavalent vaccine with the additional shots against hepatitis B. Given the assumed clinical equivalence between the two vaccination schemes, a cost-minimization analysis has been performed from a societal perspective including all the medical and non-medical direct and indirect costs when vaccinating one birth cohort. The results indicate that the ready-to-use hexavalent vaccine induces a cost reduction of KRW 47,155 (USD36.22) per infant or 12,026 million Korean Won ($9,236,417) in total for the whole birth cohort with 260,500 children. Using the ready-to-use hexavalent vaccine causes a lower infection rate, has fewer vaccination sessions, and may save much time as compared with the current vaccination scheme in place. The ready-to-use hexavalent vaccine may, therefore, benefit the National Immunization Program by reducing the total societal costs of vaccination while improving convenience of infants, parents, and medical care professionals.

Post-Marketing Safety Surveillance of a Childhood Pentavalent Diphtheria-Tetanus-Acellular Pertussis-Polio and Haemophilus influenzae Type B (DTaP-IPV//Hib) Vaccine in South Korea

INTRODUCTION

PENTAXIM™ (Sanofi), DTaP-IPV//Hib, a pentavalent combination vaccine for protection against diphtheria, tetanus, pertussis, poliomyelitis, and invasive infections caused by Haemophilus influenzae type b, has been licensed in South Korea by the Ministry of Food and Drug Safety (MFDS) on May 9, 2016, and is currently used in routine vaccination. The aim of this phase IV study, conducted as a post-licensure commitment in South Korea, was to evaluate the safety of the DTaP-IPV//Hib vaccine when administered in infants at 2, 4, and 6 months of age in the real-world clinical practice.

METHODS

This multicenter, observational, post-marketing surveillance (PMS) study was conducted in real-world practice in South Korea. Infants aged 2 months or older were enrolled across seven centers from July 31, 2018 to February 11, 2020. The study outcomes included occurrence, time to onset, duration, intensity, and causality assessment (for unsolicited adverse events [AEs] only) for several pre-listed solicited injection-site and systemic reactions, unsolicited AEs, and serious adverse events (SAEs).

RESULTS

Data from 619 participants were included in the safety analysis. Overall, 618 AEs were reported by 273 (44.1%) participants consisting of 121 solicited injection-site reactions (15.4%), 344 solicited systemic reactions (24.6%), and 153 unsolicited AEs (15.7%) of which, 124 were unexpected AEs (12.9%) (regardless of intensity). None of the unsolicited AEs were reported to have a causal relationship with the study vaccine. One SAE of pyrexia (solicited reaction) was reported. Most AEs were of mild intensity, and all participants recovered.

CONCLUSION

This PMS study of the DTaP-IPV//Hib vaccine confirmed its safety profile in a real-life setting in South Korea and justified that the vaccine is well tolerated when used in infants aged 2 months or older for the primary series.

Immunogenicity of a liquid hexavalent DTaP-IPV-HB-PRP∼T vaccine after primary and booster vaccination of term and preterm infants born to women vaccinated with Tdap during pregnancy

BACKGROUND

Vaccination during pregnancy with tetanus, diphtheria, acellular pertussis (aP) (Tdap) antigens is important for early protection of newborn infants against pertussis, particularly for preterm infants. This study evaluated the effect of Tdap vaccination during pregnancy on the immunogenicity of a diphtheria (D), tetanus (T), aP, inactivated poliovirus (IPV), hepatitis B (HB), and Haemophilus influenzae type b (PRP ∼ T) vaccine in term and preterm populations.

METHODS

A prospective, observational study (NCT02511327) recruited women and their infants based on delivery (term or preterm) and vaccination status (vaccinated with a Tdap vaccine [Boostrix™, GlaxoSmithKline] during pregnancy or not vaccinated in the last 5 years). All infants received licensed DTaP-IPV-HB-PRP ∼ T (Hexyon™, Sanofi) (8, 12, 16 week primary series and booster at 13 months of age [preterm infants] or 15 months of age [term infants]). Immunogenicity was evaluated using validated assays. Data were pooled into term (N = 127) and preterm infants (N = 105), and infants of women who received a Tdap vaccine during pregnancy (N = 199) or not (N = 33).

RESULTS

Before primary vaccination, antibody levels were higher for term than preterm infants for anti-D, anti-polio 1, 2, 3, anti-PT, anti-FHA, and anti-PRP, and similar for anti-HBs and anti-T. At this time, infants of Tdap-vaccinated women had higher anti-D, anti-T, anti-PT, anti-FHA, and anti-PRP antibody levels than infants of Tdap-unvaccinated women; anti-HBs and anti-polio antibody levels were similar in both groups. Post-primary, pre-booster, and post-booster, there were only small differences in seroprotection rates (anti-D, anti-T, anti-polio 1, 2, 3, anti-HBs, anti-PRP) and seroconversion rates (anti-PT, anti-FHA), except for anti-HBs ≥ 10 mIU/mL and anti-PRP ≥ 0.15 µg/mL post-primary vaccination (higher for term [98.31 % and 90.91 %, respectively] versus preterm infants [89.80 % and 79.41 %, respectively]).

CONCLUSIONS

These data support the use of DTaP-IPV-HB-PRP ∼ T vaccine for primary and booster vaccination in term and preterm born infants and in infants born to Tdap-vaccinated or Tdap-unvaccinated women.

A review of the DTaP-IPV-HB-PRP-T Hexavalent vaccine in pediatric patients

INTRODUCTION

Hexaxim is a hexavalent vaccine approved as primary and booster vaccination in infants 6 weeks and older, protecting against diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B and Haemophilus influenzae type b.

AREAS COVERED

To evaluate the immunogenicity and reactogenicity (safety) of Hexaxim (Hexyon, Hexacima) in primary and booster vaccine schedules; long-term antibody persistence; concomitant use with other childhood vaccines and use in immunocompromised infants. Hexaxim was found to be noninferior to other licensed hexavalent vaccines, being highly immunogenic for all toxoids/antigens and with an acceptable safety profile. It can be administered concomitantly with other childhood vaccines. Hexaxim can be given as a booster for infants primed with Infanrix Hexa and given in a pentavalent-hexavalent-pentavalent series. Hexaxim elicits a similar immune response and safety profile in human immunodeficiency virus (HIV) positive infants. It has the benefit of being a ready-to-use liquid formulation, minimizing dosage errors and preparation time.

EXPERT OPINION

Hexaxim has an acceptable safety profile and provides immunity against all six targeted diseases. It is an acceptable alternative to other hexavalent vaccines on the market. Further studies are required on the use of immunocompromised patients as well as the antibody persistence of each of the vaccine components.

Lot-to-lot consistency of a hexavalent DTwP-IPV-HB-PRP∼T vaccine and non-inferiority to separate DTwP-HB-PRP∼T and IPV antigen-matching vaccines at 6–8, 10–12, and 14–16 weeks of age co-administered with oral rotavirus vaccine in healthy infants in India: A multi-center, randomized, controlled study

Background

Combination vaccines reduce the number of pediatric injections but must be as safe, immunogenic, and effective as each of the individual vaccines given separately. Additionally, consistency in manufacturing lots is essential for WHO prequalification. This study aimed to establish the lot-to-lot consistency of a fully liquid, hexavalent diphtheria (D)-tetanus (T)-whole-cell pertussis (wP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b (PRP-T) (DTwP-IPV-HB-PRP∼T) vaccine and to demonstrate non-inferiority to licensed DTwP-HB-PRP∼T and IPV vaccines.

Methods

A Phase III, randomized, active-controlled, and open-label study was conducted at multiple centers across India. Healthy infants who had received a birth dose of oral poliovirus vaccine and hepatitis B vaccine received one of three lots of DTwP-IPV-HB-PRP∼T or separate DTwP-HB-PRP∼T and IPV vaccines at 6–8, 10–12, and 14–16 weeks of age. Oral rotavirus vaccine was co-administered at 6–8 weeks of age and 10–12/14–16 weeks of age. DTwP-IPV-HB-PRP∼T lot-to-lot consistency and non-inferiority (pooled DTwP-IPV-HB-PRP∼T) versus DTwP-HB-PRP∼T and IPV post-third dose were assessed using seroprotection rates (anti-D, anti-T, anti-HBs, anti-PRP, anti-polio 1, 2, 3) and adjusted geometric mean concentrations (anti-PT, anti-FIM). Safety was assessed by parental reports.

Results

Lot-to-lot consistency was demonstrated for DTwP-IPV-HB-PRP∼T and non-inferiority versus DTwP-HB-PRP∼T and IPV was confirmed with 95% CIs for seroprotection rate differences and adjusted geometric mean concentration ratios within pre-defined clinical margins. Pooled seroprotection rate was ≥ 99.7% for anti-D ≥ 0.01 IU/mL, anti-T ≥ 0.01 IU/mL, anti-HBs ≥ 10 mIU/mL, anti-PRP ≥ 0.15 µg/mL, and anti-polio 1, 2, and 3 ≥ 8 (1/dil) and vaccine response rate was 83.9% for anti-PT and 97.7% for anti-FIM. There were no safety concerns.

Conclusions

Immunogenicity of three lots of the fully liquid DTwP-IPV-HB-PRP∼T vaccine was consistent and non-inferior to licensed comparators following vaccination at 6–8, 10–12, and 14–16 weeks of age. There were no safety concerns and no evidence of any effect of co-administration with rotavirus vaccine.

Public health perspective of a pentavalent meningococcal vaccine combining antigens of MenACWY-CRM and 4CMenB

OBJECTIVES

Invasive meningococcal disease (IMD) is a life-threatening disease that can rapidly progress to death or leave survivors with severe, life-long sequelae. Five meningococcal serogroups (A, B, C, W and Y) account for nearly all IMD. Meningococcal serogroup distribution fluctuates over time across the world and age groups. Here, we consider the potential public health impact of a pentavalent MenABCWY vaccine developed to help further control meningococcal disease and improve immunisation rates.

RESULTS

The GSK MenABCWY vaccine combines the antigenic components of MenACWY-CRM (Menveo®) and 4CMenB (Bexsero®), building on a wide body of clinical experience and real-world evidence. Both approved vaccines have acceptable safety profiles, demonstrate immunogenicity, and are broadly used, including in national immunisation programmes in several countries. Since the advent of quadrivalent vaccines, public health in relation to IMD has improved, with a decline in the overall incidence of IMD and an increase in vaccine coverage.

CONCLUSION

A pentavalent MenABCWY has the potential to provide further public health benefits through practical, broad IMD protection programmes encompassing serogroups A, B, C, W and Y, and is currently in late-stage development.

Post-Marketing Surveillance of Tetravalent Diphtheria-Tetanus-Acellular Pertussis and Inactivated Poliovirus (DTaP-IPV) Vaccine in South Korea, 2009 to 2015

Introduction

TETRAXIM™ (Sanofi), a combined diphtheria, tetanus, acellular pertussis, and inactivated poliovirus (DTaP-IPV) vaccine, has been licensed in South Korea since 2009. In accordance with the Ministry of Food and Drug Safety regulations, this post-marketing surveillance (PMS) study evaluated the safety of the DTaP-IPV vaccine in real-world clinical practice in infants and children who received it as either a part of the three-dose primary series dose at 2, 4, and 6 months or school entry booster between 4 and 6 years of age.

Methods

This multicenter, observational, PMS study was conducted in real-world practice in South Korea for 6 years (2009–2015) in participants aged between 2 months and 6 years. The study outcomes included solicited reactions, unsolicited adverse events (AEs)/adverse drug reactions (ADRs), unexpected AEs/ADRs, and serious AEs (SAEs)/ADRs.

Results

Data from 647 participants was included in the safety analysis. Overall, 268 AEs were reported by 181 (28%) participants: 47 (17.5%) solicited reactions, 220 (82.1%) unsolicited AEs, and 1 (0.4%) unsolicited ADR. A total of 48 AEs (including 47 solicited reactions) were reported to have a causal relationship with the DTaP-IPV vaccine and were reported by 36 (5.6%) participants. A total of 212 unexpected AEs were reported by 152 (23.5%) participants, none of which had a causal relationship with the DTaP-IPV vaccine. Neither immediate AEs nor SAEs were reported during the study. Among the participants who reported AEs, 220 (34%) were on concomitant medications. Most AEs were of mild intensity, and all participants recovered.

Conclusion

No safety concerns related to the DTaP-IPV vaccine in a real-world setting were raised in participants aged 2–6 months for the primary series and 4–6 years for the school-entry booster dose in the Korean population. The DTaP-IPV vaccine was well tolerated and can be continued as part of routine immunization programs in infants and children.

Trial Registration: NCT01437423.

Safety and immunogenicity of a hexavalent DTwP-IPV-HB-PRP∼T vaccine versus separate DTwP-HB-PRP∼T and IPV vaccines in healthy infants in India

Background

Multivalent vaccines containing whole-cell pertussis (wP) antigens combined with established diphtheria (D), tetanus (T), hepatitis B (HB), Haemophilus influenzae type b (Hib), and inactivated poliomyelitis (IPV) antigens allow the provision of a high-quality, affordable DTwP-IPV-HB-PRP∼T vaccine.

Methods

Phase I/II, randomized, active-controlled, open-label study in healthy toddlers (Cohort I) and infants (Cohort II). Toddlers in Cohort I who had completed primary series D, T, P, HB, Hib, and polio vaccination received a booster dose of DTwP-IPV-HB-PRP∼T (N = 30) or DTwP-HB-PRP∼T + IPV (N = 15) vaccines at 15–18 months of age. After satisfactory review of safety data in Cohort I, infants in Cohort II received DTwP-IPV-HB-PRP∼T (N = 100) or DTwP-HB-PRP∼T + IPV (N = 50) at 6–8, 10–12, and 14–16 weeks of age. All infants in Cohort II had received previous oral polio and HB vaccines per country recommendations.

Results

Booster and primary series vaccinations were well tolerated with no clinically significant differences between vaccine groups. Most adverse events were mild and resolved spontaneously; there were no vaccine-related serious adverse events and no deaths. In both vaccine groups, anti-D, anti-T, anti-HB, anti-Hib, and anti-polio 1, 2, and 3 seroprotection was 100% post-booster and post-primary series. For the pertussis antigens, booster response rate was > 86% in both groups. For the primary series, vaccine response rate was slightly higher for DTwP-IPV-HB-PRP∼T than DTwP-HB-PRP∼T + IPV for anti-PT (80.2% and 70.8%) and anti-FHA (81.3% and 68.8%), slightly lower for anti-PRN (72.5% and 81.3%), and similar in each group for anti-FIM (95.6% and 97.9%).

Conclusions

This study demonstrated a good safety and immunogenicity profile of the hexavalent DTwP-IPV-HB-PRP∼T vaccine for infant primary series vaccination at 6–8, 10–12, and 14–16 weeks of age and booster vaccination at 15–18 months of age and supported progression to the next development phase.

A Comparison with Adverse Events Following Immunization Associated with Sabin-Strains and Salk-Strains Inactivated Polio Vaccines in Zhejiang Province, China

Objectives: One dose of Sabin-strains inactivated polio vaccine (IPV) was introduced into the Chinese immunization program on 1 May 2016. This study aimed to evaluate the safety of Sabin-strains IPV and provide a comparison with conventional Salk-strains IPV. Methods: Adverse events following immunization (AEFI) records associated with Sabin-strains IPV and Salk-strains IPV were extracted from the national AEFI surveillance system (NAEFISS) from 1 May 2016 to 31 December 2020. The vaccination information on Sabin-strains IPV and Salk-strains IPV during the same period was obtained from the Zhejiang provincial immunization information system. Reporting rates of AEFI were calculated by age, city, severity of AEFI, categories of AEFI, and reaction categories and were compared between Sabin-strains IPV and Salk-strains IPV. Results: In total, 3,861,758 doses of Sabin-strains IPV and 1,018,604 doses of Salk-strains IPV were administered during the study period. The overall AEFI reporting rate for Sabin-strains IPV (3.96/10,000 doses) was significantly lower than that for Salk-strains IPV (5.03/10,000 doses) due to the reporting rate of the minor vaccine product-related reaction following Sabin-strains IPV was significantly lower than that for Salk-strains IPV (2.76/10,000 doses vs. 3.83/10,000 doses). The most frequently reported symptoms/signs were fever, induration/swelling, and rash/urticaria. The most frequently reported serious AEFI with a causal relationship was febrile convulsion, with the reporting rates of 0.10/10,000 doses for Sabin-strains IPV and 0.08/10,000 doses for Salk-strains IPV. No significant difference was found in the reporting rates of the other serious AEFI between the two types of IPV. Conclusion: Most of the AEFI following Sabin-strains IPV and Salk-strains IPV were mild and common adverse reactions. The reporting rate of serious AEFI was not significantly different between Sabin-strains IPV and Salk-strains IPV. Sabin-strains IPV had a favorable safety profile and could be widely used.

Recommendation for use of diphtheria and tetanus toxoids and acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b conjugate, and hepatitis B vaccine in infants

In April 2020, the Ministry of Food and Drug Safety licensed a hexavalent combined diphtheria and tetanus toxoids and acellular pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib) conjugated to tetanus protein, and hepatitis B (HepB) (recombinant DNA) vaccine, DTaP-IPV-Hib-HepB (Hexaxim, Sanofi Pasteur), for use as a 3-dose primary series in infants aged 2, 4, and 6 months. The DTaP-IPV-Hib-HepB vaccine is highly immunogenic and safe and provides a long-term immune response based on studies performed in a variety of settings in many countries, including Korea. This report summarizes the Committee on Infectious Diseases of the Korean Pediatric Society guidelines for the use of this newly introduced hexavalent combination vaccine.

Hib Vaccines: Their Impact on Haemophilus influenzae Type b Disease

Haemophilus influenzae serotype b (Hib) is an important cause of serious, invasive infections, particularly in young children. Since 1985, a series of vaccines composed of the type b capsular polysaccharide polyribosylribitol phosphate (PRP), followed by PRP conjugated to various proteins, have been licensed for use in the United States and worldwide. The conjugated vaccines offer increased immunogenicity and prolonged durability of immune protection compared to the plain PRP vaccine and increasingly are combined with other childhood vaccines for decreased cost and increased ease of vaccination. Hib vaccines have a very favorable safety profile, have been found to be either cost-saving or cost-effective by many public health agencies, and, in most countries, are initiated during early infancy as part of routine childhood immunization programs. As a result of widespread use of the vaccines, the incidence of Hib infections, and their associated morbidity and mortality, has fallen dramatically across the globe. Yet, many children remain unimmunized or underimmunized against Hib, particularly in limited-resource countries. Future efforts to further reduce the disease burden of Hib infections remain a high priority.

Surveillance of adverse events following the introduction of inactivated poliovirus vaccine made from Sabin strains (sIPV) to the Chinese EPI and a comparison with adverse events following inactivated poliovirus vaccine made from wild strains (wIPV) in Jiangsu, China

One dose of inactivated poliovirus vaccine (IPV) was introduced into the Chinese Expanded Program on Immunization (EPI) in 2016. IPV made from Sabin strains (sIPV) was newly licensed in China and its safety has been concerned. This study aimed to evaluate the safety of sIPV and provide a comparison with conventional IPV made from wild strains (wIPV). We collected all IPV-related AEFI reports in Jiangsu from the Chinese National Adverse Events Following Immunization Information System (CNAEFIS) for 2016-2019. We obtained the administered doses of IPV from the Jiangsu provincial Electronic Immunization Registries System (JSEIRS). The AEFI reporting rates per 100,000 doses of vaccine administered were compared for sIPV and wIPV. A total of 699 sIPV and 908 wIPV AEFI cases were collected by CNAEFIS in Jiangsu during 2016-2019. The overall AEFI reporting rates were 53.02 per 100,000 doses and 41.25 per 100,000 doses for sIPV and wIPV, respectively (P < .001). For both sIPV and wIPV, the AEFIs were mainly classified as common adverse reactions. The reporting rate of common adverse reactions was higher for sIPV than for wIPV (P < .001). The most frequently reported symptoms/signs were fever, persistent crying, injection site erythema/swelling, rash, and injection site induration. Only 1.14% of sIPV-associated and 2.31% of wIPV-associated AEFI cases were diagnosed as serious. No difference in reporting rate was observed for serious AEFIs (P = .272). sIPV has a favorable safety profile, although it exhibits a slightly higher reporting rate of common adverse reactions than wIPV.

Hexavalent vaccines in infants: a systematic literature review and meta-analysis of the solicited local and systemic adverse reactions of two hexavalent vaccines

Introduction: The hexavalent vaccine DT3aP-HBV-IPV-Hib (Infanrix hexa, GSK) was first licensed in Europe in 2000. DT2aP-HBV-IPV-Hib (Hexyon/Hexacima/Hexaxim, Sanofi Pasteur), and DT5aP-HBV-IPV-Hib (Vaxelis, MCM Vaccine Company) were licensed in the EU in 2013 and 2016, respectively, based largely on studies demonstrating non-inferiority to DT3aP-HBV-IPV-Hib for immunogenicity and comparable reactogenicity profiles.Methods: We conducted a systematic literature review looking for direct head-to-head trials comparing DT2aP-HBV-IPV-Hib and DT5aP-HBV-IPV-Hib with DT3aP-HBV-IPV-Hib. The incidence of solicited local and systemic reactions following primary series administration of DT3aP-HBV-IPV-Hib or DT2aP-HBV-IPV-Hib were meta-analyzed.Results: A total of 317 unique records were retrieved from the search; nine met the predefined inclusion criteria; seven reported studies comparing DT3aP-HBV-IPV-Hib and DT2aP-HBV-IPV-Hib. Six trials assessing outcomes of the primary vaccination series were identified. Odds ratios and 95% confidence intervals (OR; 95%CI) were computed for DT3aP-HBV-IPV-Hib, using DT2aP-HBV-IPV-Hib as reference, for redness (0.72; 0.63-0.83), pain (0.74; 0.62-0.89), swelling (0.86; 0.74-0.99) at injection site, fever (0.67; 0.54-0.83), persistent crying (0.72; 0.61-0.84), drowsiness (0.82; 0.71-0.94), irritability (0.82; 0.69-0.98), anorexia (0.83; 0.72-0.95), and vomiting (0.96; 0.83-1.11).Conclusion: ORs of analyzed local and systemic solicited adverse reactions after primary vaccination with DT3aP-HBV-IPV-Hib appear to be slightly lower than with DT2aP-HBV-IPV-Hib.

Control of vaccine preventable diseases in Australian infants: reviewing a decade of experience with DTPa-HBV-IPV/Hib vaccine

The combined vaccine against diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and Haemophilus influenzae b (DTPa-HBV-IPV/Hib, Infanrix Hexa, GSK) has been used for childhood immunization in Australia according to a two-, four-, six-month schedule since 2009. We reviewed data available in the Australian National Notifiable Diseases Surveillance System, annual vaccination coverage reports, the Database of Adverse Event Notifications, and peer-reviewed literature to assess vaccine coverage rates, incidence of all six vaccine preventable diseases, and the safety profile of DTPa-HBV-IPV/Hib vaccine in Australian infants over a period of ten years of exclusive use. Between 2009 and 2018 vaccine coverage for infants aged 12 months increased from 91.7% to 94.0% and from 84.9% to 92.6% for all and for Indigenous infants, respectively. Over the same time period, there were no reports of poliomyelitis, diphtheria or tetanus in infants <12 months of age. The incidence of hepatitis B among Australian infants <12 months of age remains 10 to 20-fold lower than the national average. Control of Haemophilus influenzae b (Hib) and pertussis disease has continued to be challenging. Timely administration of the primary series, as well as increasing coverage rates, particularly among Indigenous children, has contributed to improvements in Hib and pertussis disease control. The incorporation of additional strategies such as adjustment of the first vaccination encounter to six weeks of age, parental cocooning, and most recently maternal vaccination has further reduced the burden of pertussis, particularly during the first six months of life. The frequency of the ten most common adverse events related to the DTPa-HBV-IPV/Hib vaccine demonstrates an acceptable safety profile. Data collected over ten years of consistent, exclusive use of the DTPa-HBV-IPV/Hib vaccine in Australia highlights combination vaccination as a cornerstone in maintaining infant health.

Biomaterials as Tools to Decode Immunity

The immune system has remarkable capabilities to combat disease with exquisite selectivity. This feature has enabled vaccines that provide protection for decades and, more recently, advances in immunotherapies that can cure some cancers. Greater control over how immune signals are presented, delivered, and processed will help drive even more powerful options that are also safe. Such advances will be underpinned by new tools that probe how immune signals are integrated by immune cells and tissues. Biomaterials are valuable resources to support this goal, offering robust, tunable properties. The growing role of biomaterials as tools to dissect immune function in fundamental and translational contexts is highlighted. These technologies can serve as tools to understand the immune system across molecular, cellular, and tissue length scales. A common theme is exploiting biomaterial features to rationally direct how specific immune cells or organs encounter a signal. This precision strategy, enabled by distinct material properties, allows isolation of immunological parameters or processes in a way that is challenging with conventional approaches. The utility of these capabilities is demonstrated through examples in vaccines for infectious disease and cancer immunotherapy, as well as settings of immune regulation that include autoimmunity and transplantation.

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.

Hexavalent vaccines in preterm infants: an update by Italian Society of Pediatric Allergy and Immunology jointly with the Italian Society of Neonatology

Hexavalent vaccines, protecting against six diseases (diphtheria, tetanus, pertussis [DTaP], poliovirus, hepatitis B virus [HBV], and Haemophilus influenzae type b [Hib], are routinely the standard of care in Europe. The use of combined vaccines allows the reduction of number of injections and side effects, the reduction of costs, and the increase in adherence of the family to the vaccination schedule both in terms of the number of doses and timing. The safety profile, efficacy and effectiveness of hexavalent vaccines have been extensively documented in infants and children born at term, and data are accumulating in preterm infants. Hexavalent vaccines are particularly important for preterm infants, who are at increased risk for severe forms of vaccine preventable diseases. However, immunization delay has been commonly reported in this age group. All the three hexavalent vaccines currently marketed in Italy can be used in preterm infants, and recent data confirm that hexavalent vaccines have a similar or lower incidence of adverse events in preterm compared to full-term infants; this is likely due to a weaker immune system response and reduced ability to induce an inflammatory response in preterm infants. Apnoea episodes are the adverse events that can occur in the most severe preterm infants and / or with history of respiratory distress. The risk of apnoea after vaccination seems to be related to a lower gestational age and a lower birth weight, supporting the hypothesis that it represents an unspecific response of the preterm infant to different procedures. High seroprotection rates have been reported in preterm infants vaccinated with hexavalent vaccine. However, a lower gestational age seems to be associated with lower antibody titres against some vaccine antigens (e.g. HBV, Hib, poliovirus serotype 1, and pertussis), regardless of the type of hexavalent vaccine used. Waiting for large effectiveness studies, hexavalent vaccines should be administered in preterm infants according to the same schedule recommended for infants born at term, considering their chronological age and providing an adequate monitoring for cardio-respiratory events in the 48–72 h after vaccination, especially for infants at risk of recurrence of apnoea.

New Horizons of National Immunization Calendar

Containment, prevention and elimination of infectious disease is the state duty for citizens. Development of the National Immunization Calendar as well as challenges in preventive vaccination system both are significant investment into the future. Advantages of vaccination are not limited only by infection diseases control. Experts of World Health Organization recognize positive influence of immunization on economic. Vaccines give unprecedented opportunities on alleviation of human sufferings but it can be possible only due to perfect work of immunization calendar. It is necessary to estimate our National Immunization Calendar alongside with suggested by World Health Organization and professional associations plans. It is essential to estimate experience and facilities of modern vaccinology. This entailed the optimal preventive vaccination schedule, which can be implemented in the structure of existing national calendar.

Evaluation of a Hexavalent-Pentavalent-Hexavalent Infant Primary Vaccination Series Followed by a Pentavalent Booster Vaccine in Healthy Infants and Toddlers

BACKGROUND

This study assessed a pediatric mixed hexavalent diphtheria (D)-tetanus (T)-acellular pertussis (aP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b [polyribosylribitol phosphate (PRP-T)]-pentavalent (DTaP-IPV//PRP-T)-hexavalent primary series schedule followed by a pentavalent booster.

METHODS

Healthy infants (N = 265) who had received a prior HB vaccination received a fully liquid, hexavalent vaccine (DTaP-IPV-HB-PRP-T) at 2 and 6 months of age and a reconstituted pentavalent vaccine (DTaP-IPV//PRP-T) at 4 months of age. Coadministered vaccines were pneumococcal vaccine at 2 and 4 months (and optionally at 6 months of age), rotavirus vaccine at 2, 4, 6 months and meningococcal serogroup C vaccine at 2 months. At 18 months, participants received DTaP-IPV//PRP-T and pneumococcal vaccine boosters. Immunogenicity was assessed using validated assays and safety by parental reports.

RESULTS

For the hexavalent and pentavalent vaccines, the primary series and booster immune responses in terms of seroprotection and vaccine response rates were high for all antigens (generally > 99% and > 95% for the primary series and booster, respectively) and prebooster antibody persistence was good for all antigens (in particular, 92.4% of participants had prebooster anti-HB antibody ≥ 10 mIU/mL). The incidence of solicited reactions was lower after the booster vaccination (56.9%-73.1%) than the primary series (76.6%-97.4%); there were few vaccine-related unsolicited adverse events (1.9% and 1.5% for the primary series and booster, respectively), none led to participant discontinuation and none was serious.

CONCLUSIONS

This study provides data that allow recommending authorities to consider the use of a sequential hexavalent-pentavalent-hexavalent primary vaccination series followed by a pentavalent booster in coadministration with other common childhood vaccines.

DTaP-IPV-HepB-Hib Vaccine (Hexyon®): An Updated Review of its Use in Primary and Booster Vaccination

Hexyon^® is a fully-liquid, ready-to-use, hexavalent vaccine approved in the EU since 2013 for primary and booster vaccination in infants and toddlers from age 6 weeks against diphtheria, tetanus, pertussis, hepatitis B (HB), poliomyelitis, and invasive diseases caused by Haemophilus influenzae type b (Hib). While the source of HB antigen in Hexyon^® is different from other vaccines, the rest of its valences have been extensively used in other approved vaccines. Hexyon^® is highly immunogenic for all its component toxoids/antigens when used as primary and booster vaccine in infants and toddlers, irrespective of vaccination schedule. It provides durable protection against hepatitis B. Hexyon^® can be used for a mixed primary series of hexavalent-pentavalent-hexavalent vaccines or as a booster in infants primed with Infanrix hexa™ or pentavalent (whole-cell or acellular pertussis) vaccines. Coadministration of Hexyon^® with other common childhood vaccines did not affect immune response to any vaccines. Hexyon^® has a good reactogenicity/safety profile. The immunogenicity and safety profile of Hexyon^® was similar to that of several approved vaccines, including Infanrix hexa™. However, Hexyon^® offers the convenience of full-liquid, ready-to-use formulation, which may minimize vaccination errors and preparation time. Thus, Hexyon^® is a convenient, useful option for vaccination against childhood diseases caused by six major pathogens.

Hexavalent vaccines: characteristics of available products and practical considerations from a panel of Italian experts

Combination vaccines represent a valuable technological innovation in the field of infectious disease prevention and public health, because of their great health and economic value from the individual, societal, and healthcare system perspectives. In order to increase parents' and healthcare professionals' confidence in the vaccination programs and maintain their benefits to society, more information about the benefits of innovative vaccination tools such as combination vaccines is needed. Purpose of this work is an examination of available hexavalent vaccines, that protect against Diphtheria, Tetanus, Pertussis, Poliomyelitis, Hepatitis B and Haemophilus influenzae type b infections. From the epidemiological updates of vaccine preventable diseases to the vaccine development cycle, from the immunogenicity of antigenic components to the safety and co-administration with other vaccines, several aspects of available hexavalent vaccines are discussed and deepened. Also a number of practical considerations on schedules, age of employment, strategies for vaccination recovery, vaccination in at-risk births are issued, based on the recommendations of Italian Ministry of Health, Italian Society of Pharmacology (SIF), Italian Society for Pediatrics (SIP), Italian Federation of Family Paediatricians (FIMP) and Italian Society of Hygiene, Preventive Medicine and Public Health (SItI).