Safety and immunogenicity of a toddler dose following an infant series of a hexavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b, hepatitis B vaccine administered concurrently or at separate visits with a heptavalent pneumococcal conjugate vaccine

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.

Determining Which of Several Simultaneously Administered Vaccines Increase Risk of an Adverse Event

INTRODUCTION

Childhood immunization schedules often involve multiple vaccinations per visit. When increased risk of an adverse event is observed after simultaneous (same-day) vaccinations, it can be difficult to ascertain which triggered the adverse event. This methods paper discusses a systematic process to determine which of the simultaneously administered vaccine(s) are most likely to have caused an observed increase in risk of an adverse event.

METHODS

We use an example from the literature where excess risk of seizure was observed 1 day after vaccination, but same-day vaccination patterns made it difficult to discern which vaccine(s) may trigger the adverse event. We illustrate the systematic identification process using a simulation that retained the observed pattern of simultaneous vaccination in an empirical cohort of vaccinated children. We simulated "true" effects for diphtheria-tetanus-acellular pertussis (DTaP) and pneumococcal conjugate (PCV) on risk of seizure the day after vaccination. We varied the independent and interactive effects of vaccines (on the multiplicative scale). After applying the process to simulated data, we evaluated risk of seizure 1 day after vaccination in the empirical cohort.

RESULTS

In all simulations, we were able to determine which vaccines contributed to excess risk. In the empirical data, we narrowed the association with seizure from all vaccines in the schedule to three likely candidates, DTaP, PCV, and/or Haemophilus influenzae type B (HiB) (p < 0.01, attributable risk when all three were administered together: five per 100,000). Disentangling their associations with seizure would require a larger sample or more variation in the combinations administered. When none of these three were administered, no excess risk was observed.

CONCLUSION

The process outlined could provide valuable information on the magnitude of potential risk from individual and simultaneousvaccinations. Associations should be further investigated with independent data as well as biologically based, statistically independent hypotheses.

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.

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 of Co-Administration Versus Separate Administration of the Same Vaccines in Children: A Systematic Literature Review

The growing number of available vaccines that can be potentially co-administered makes the assessment of the safety of vaccine co-administration increasingly relevant but complex. We aimed to synthesize the available scientific evidence on the safety of vaccine co-administrations in children by performing a systematic literature review of studies assessing the safety of vaccine co-administrations in children between 1999 and 2019, in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Fifty studies compared co-administered vaccines versus the same vaccines administered separately. The most frequently studied vaccines included quadrivalent meningococcal conjugate (MenACWY) vaccine, diphtheria and tetanus toxoids and acellular pertussis (DTaP) or tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccines, diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B, inactivated poliovirus and Haemophilus influenzae type b conjugate (DTaP-HepB-IPV/Hib) vaccine, measles, mumps, and rubella (MMR) vaccine, and pneumococcal conjugate 7-valent (PCV7) or 13-valent (PCV13) vaccines. Of this, 16% (n = 8) of the studies reported significantly more adverse events following immunization (AEFI) while in 10% (n = 5) significantly fewer adverse events were found in the co-administration groups. Statistically significant differences between co-administration and separate administration were found for 16 adverse events, for 11 different vaccine co-administrations. In general, studies briefly described safety and one-third of studies lacked any statistical assessment of AEFI. Overall, the evidence on the safety of vaccine co-administrations compared to separate vaccine administrations is inconclusive and there is a paucity of large post-licensure studies addressing this issue.

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.

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

BACKGROUND

DTaP5-HB-IPV-Hib is a fully liquid, hexavalent vaccine containing a 5-antigen pertussis component, approved since 2016 in Europe [Vaxelis; DTaP5-HB-IPV-Hib vaccine: Diphtheria, tetanus, pertussis (5 acellular components: pertussis toxoid [PT], filamentous haemagglutinin [FHA], pertactin (PRN), and fimbriae Types 2 and 3 [FIM]), hepatitis B (recombinant DNA: rDNA), poliomyelitis (inactivated) and Haemophilus influenzae type b conjugate vaccine (adsorbed); MCM Vaccine B.V., The Netherlands] for primary and booster vaccination in infants and toddlers against diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis and invasive diseases caused by Haemophilus influenzae type b. The comparator vaccine (control) was INFANRIX hexa (GlaxoSmithKline Biologics S.A., Rixensart, Belgium) (DTaP3-IPV-HepB/Hib) in European studies and PENTACEL (DTaP5-IPV/Hib) (Sanofi Pasteur, Swiftwater, PA) in US studies.

METHODS

Data from 6 studies were integrated and analyzed to provide a comprehensive safety profile. Numbers and proportions of subjects with adverse events (AEs) were summarized by treatment group. Group differences in proportion of AEs were calculated.

RESULTS

Among the DTaP5-HB-IPV-Hib (N = 5223) and 2295 control (N = 2295) groups, solicited injection-site and systemic AEs were very common. Serious AEs were reported by 3.9% of DTaP5-HB-IPV-Hib and 3.7% of control subjects. Vaccine-related serious AEs occurred infrequently, 0.2% for both groups. Most AEs were mild-to-moderate and did not lead to subject withdrawal. Group differences for solicited systemic AEs were small (<3%) and not statistically significant, except for pyrexia (estimated difference 9.4% [95% CI: 6.7%-12%]). The difference was driven by the 2 US studies where the PENTACEL control group had a lower fever rate. Among European studies, there was no significant difference in rates of pyrexia between DTaP5-HB-IPV-Hib and INFANRIX hexa.

CONCLUSIONS

The safety of DTaP5-HB-IPV-Hib is consistent with the safety profile of its components and similar to comparator vaccines, including INFANRIX hexa. The vaccine provides a new, fully liquid and convenient hexavalent vaccination option for use with various vaccination schedules in Europe.

Methods for addressing "innocent bystanders" when evaluating safety of concomitant vaccines

PURPOSE

The need to develop methods for studying the safety of childhood immunization schedules has been recognized by the Institute of Medicine and Department of Health and Human Services. The recommended childhood immunization schedule includes multiple vaccines in a visit. A key concern is safety of concomitant (same day) versus separate day vaccination. This paper addresses a methodological challenge for observational studies using a self-controlled design to investigate the safety of concomitant vaccination.

METHODS

We propose a process for distinguishing which of several concomitantly administered vaccines is responsible for increased risk of an adverse event while adjusting for confounding due to relationships between effect modifying risk factors and concomitant vaccine combinations. We illustrate the approach by re-examining the known increase in risk of seizure 7 to 10 days after measles-mumps-rubella (MMR) vaccination and evaluating potential independent or modifying effects of other vaccines.

RESULTS

Initial analyses suggested that DTaP had both an independent and potentiating effect on seizure. After accounting for the relationship between age at vaccination and vaccine combination, there was little evidence for increased risk of seizure with same day administration of DTaP and MMR; incidence rate ratio, 95% confidence interval 1.2 (0.9-1.6), P value = θ.226.

CONCLUSION

We have shown that when using a self-controlled design to investigate safety of concomitant vaccination, it can be critically important to adjust for time-invariant effect modifying risk factors, such as age at time of vaccination, which are structurally related to vaccination patterns due to recommended immunization schedules.

New perspectives for hexavalent vaccines

With the increase in the number of routine vaccinations the development of pentavalent and hexavalent combination vaccines fitting the routine vaccination schedules became a necessity. In this respect, Europe has taken the lead in comparison with other world regions, and routine vaccination with pentavalent and hexavalent combinations including DTPa, Hib, HepB and IPV has been on European vaccination programs for >15years. Since the marketing authorization of Hexavac® and Infanrix Hexa® in 2000, immunization schedules in most European countries have included hexavalent vaccines. In the last years, two new hexavalent vaccines have been licensed and commercialized worldwide. This paper presents a review of the pharmaceutical profiles of the three hexavalent vaccines currently available. In addition, we aim to review safety, co-administration, tolerability and other practical concerns of their use.

DTaP5-HB-IPV-Hib Vaccine (Vaxelis®): A Review of its Use in Primary and Booster Vaccination

Vaxelis^® is a fully liquid, ready-to-use, hexavalent vaccine approved in the EU for primary and booster vaccination in infants and toddlers from the age of 6 weeks against diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and invasive diseases caused by Haemophilus influenzae type b (Hib). It contains diphtheria and tetanus toxoids, five acellular pertussis antigens, recombinant hepatitis B virus surface antigen produced in the yeast, Saccharomyces cerevisiae, inactivated poliovirus, and the Hib polysaccharide (polyribosylribitol phosphate) conjugated to the outer membrane protein complex of Neisseria meningitidis. In pivotal clinical studies, Vaxelis^® was highly immunogenic for all its component toxoids/antigens when administered by three different schedules. Primary endpoints of seroprotection or vaccine response rates with Vaxelis^® met the predefined acceptability criteria and were noninferior to those with comparator vaccines (Infanrix^® hexa or Pentacel^® plus Recombivax HB^®). Limited data indicate that immune responses to Vaxelis^® in preterm infants were generally similar to those seen in the overall population. Vaxelis^® can be coadministered with a number of common childhood vaccines. In clinical studies, Vaxelis^® was generally well tolerated with a tolerability profile similar to that of the comparator vaccines. Available clinical data indicate that Vaxelis^® is a new hexavalent vaccine option for immunization against several serious childhood infectious diseases.

Paediatricians require more information before they routinely co-administer the meningococcal B vaccine with routine infant vaccines

AIM

The four-component meningococcal serogroup B (4CMenB) vaccine was licensed by the European Medicines Agency in 2013. We evaluated current practice regarding multiple vaccines and the attitudes of paediatricians towards the 4CMenB before it became available in Austria in 2014.

METHODS

We sent 1624 Austrian paediatricians an email invitation to participate in our nationwide web-based survey and 231 responded.

RESULTS

Most participants regarded the 4CMenB vaccine as a long-needed and necessary tool against meningococcal B disease. However, most participants would not co-administer this vaccine with other routine infant vaccines. The survey showed that 58.9% of paediatricians already co-administered the hexavalent vaccine with the pneumococcal conjugate vaccine, but most of them would not add a third vaccine at the same visit. This was mainly due to lack of experience with the vaccine and also because they assumed that parents would not consent. Importantly, paediatricians said they wanted an explicit recommendation in the Austrian Immunisation Plan on the timing of the 4CMenB vaccine before they would confidently and routinely use it for infants.

CONCLUSION

Paediatricians required more information for themselves and for parents before routinely co-administering the 4CMenB vaccine. They also requested a national recommendation on its timing.

Hepatitis B: are at-risk individuals vaccinated if screened and found negative for HBV? Results of an online survey conducted in six EU countries

INTRODUCTION

Vaccination is the best way to prevent hepatitis B infection and its consequences. The aim of the present study is to analyze the current vaccination practices within various population subgroups who are offered screening for hepatitis B, when found negative, in Germany, Hungary, Italy, the Netherlands, Spain and the UK.

METHODS

Online surveys were conducted in the six countries. In total, 1181 experts from six different health professions were invited to participate. Descriptive analyses of data were performed.

RESULTS

Less than half of the respondents in the Netherlands, only about 1/4 in Germany and none in Hungary reported that the vaccine is commonly offered to people who inject drugs. Less than half of the respondents in Germany reported vaccinating sex workers or HIV positive patients against hepatitis B as common practice. None in Hungary stated that vaccinating sex workers is common practice, and only according to a minority (17%) HIV patients are commonly vaccinated. 1/4 to 1/3 of respondents in Germany, the Netherlands, Italy, Hungary and the UK, indicated that HCV positive patients are only sporadically immunized. Only in Spain almost half of the respondents reported that migrants from hepatitis B endemic areas who are screened negative are commonly vaccinated. Widespread uncertainty about vaccination practices for asylum seekers was reported.

CONCLUSIONS

By showing the gaps between current practices and policies in place, our findings can help to increase the success of future vaccination programmes. Implementation of training for health care professional, e.g. introducing vaccinology and vaccination policy courses in the medical and paramedical curriculum, could contribute to a more homogenous application of the recommendations regarding immunization against hepatitis B. Our results show, nonetheless, that the universal vaccination approach, coupled with targeted programmes for immigrants, represents the only way to make the elimination of hepatitis B a foreseeable, realistic objective.

Timely versus delayed early childhood vaccination and seizures

BACKGROUND

Little is known regarding the timing of childhood vaccination and postvaccination seizures.

METHODS

In a cohort of 323 247 US children from the Vaccine Safety Datalink born from 2004 to 2008, we analyzed the association between the timing of childhood vaccination and the first occurrence of seizure with a self-controlled case series analysis of the first doses of individual vaccines received in the first 2 years of life.

RESULTS

In infants, there was no association between the timing of infant vaccination and postvaccination seizures. In the second year of life, the incident rate ratio (IRR) for seizures after receipt of the first measles-mumps-rubella vaccine (MMR) dose at 12 to 15 months was 2.65 (95% confidence interval [CI] 1.99-3.55); the IRR after an MMR dose at 16 to 23 months was 6.53 (95% CI 3.15-13.53). The IRR for seizures after receipt of the first measles-mumps-rubella-varicella vaccine (MMRV) dose at 12 to 15 months was 4.95 (95% CI 3.68-6.66); the IRR after an MMRV dose at 16 to 23 months was 9.80 (95% CI 4.35 -22.06).

CONCLUSIONS

There is no increased risk of postvaccination seizure in infants regardless of timing of vaccination. In year 2, delaying MMR vaccine past 15 months of age results in a higher risk of seizures. The strength of the association is doubled with MMRV vaccine. These findings suggest that on-time vaccination is as safe with regard to seizures as delayed vaccination in the first year of life, and that delayed vaccination in the second year of life is associated with more postvaccination seizures than on-time vaccination.