A comparison of booster immunisation with a combination DTPa-IPV vaccine or DTPa plus IPV in separate injections when co-administered with MMR, at age 4–6 years

Review of scientific evidence to support recommendations of the full-dose DTaP-IPV vaccination in pre-school age children in Italy

INTRODUCTION

Two vaccine formulations are available to prevent diphtheria, tetanus, pertussis, and poliomyelitis: the pediatric full-dose (DTaP-IPV) and the reduced dose formulation (dTap-IPV). Different immunization schedules are internationally recommended for the pre-school booster dose.

AREAS COVERED

International and Italian recommendations, scientific evidence on immunogenicity and safety of DTaP/dTap vaccines to support the full dose as a pre-school booster and Italian vaccination coverage (VC) up to adolescence.

EXPERT OPINION

The WHO recommends a '3+1' schedule with DTaP vaccine for primary immunization, followed by a pre-school booster with DTaP or dTap vaccine. In Italy, a '2+1' schedule, with no booster in the second year, and a pre-school booster dose are recommended with DTPa-IPV vaccines. Studies showed a non-inferior immunogenicity in dTap vaccinees in pre-school age; nevertheless, the antibody titers were usually greater in children vaccinated with DTaP, while lower frequencies of adverse events were recorded in children receiving dTap. Italian VCs for pre-school and adolescent boosters have not been satisfactory, which further reduced during the COVID-19 period. In Italy, the pre-school booster offers the last chance to receive a full dose of DTaP vaccine, thus, representing the most suitable intervention to provide lasting protection in children.

Safety of routine childhood vaccine coadministration versus separate vaccination

INTRODUCTION

As new vaccines are developed more vaccine coadministrations vaccines are being offered to make delivery more practical for health systems and patients. We compared the safety of coadministered vaccines with separate vaccination for 20 coadministrations by considering nine types of adverse events following immunisation (AEFI).

METHODS

Real-life immunisation and adverse event data for this observational cohort study were extracted from the Oxford-Royal College of General Practitioners Research and Surveillance Centre for children registered in the database between 2008 and 2018. We applied the self-controlled case series method to calculate relative incidence ratios (RIR) for AEFI. These RIRs compare the RI of AEFI following coadministration with the RI following separate administration of the same vaccines.

RESULTS

We assessed 3 518 047 adverse events and included 5 993 290 vaccine doses given to 958 591 children. 17% of AEFI occurred less and 11% more frequently following coadministration than would have been expected based on the RIs following separate vaccinations, while there was no significant difference for 72% of AEFI. We found amplifying interaction effects for AEFI after five coadministrations comprising three vaccines: for fever (RIR 1.93 (95% CI 1.63 to 2.29)), rash (RIR 1.49 (95% CI 1.29 to 1.74)), gastrointestinal events (RIR 1.31 (95% CI 1.14 to 1.49)) and respiratory events (RIR 1.27 (1.17-1.38)) following DTaP/IPV/Hib+MenC+ PCV; gastrointestinal events (RIR 1.65 (95% CI 1.35 to 2.02)) following DTaP/IPV/Hib+MenC+ RV; fever (RIR 1.44 (95% CI 1.09 to 1.90)) and respiratory events (RIR 1.40 (95% CI 1.25 to 1.57)) following DTaP/IPV/Hib+PCV+ RV; gastrointestinal (RIR 1.48 (95% CI 1.20 to 1.82)) and respiratory events (RIR 1.43 (95% CI 1.26 to 1.63)) following MMR+Hib/MenC+PCV; gastrointestinal events (RIR 1.68 (95% CI 1.07 to 2.64)) and general symptoms (RIR 11.83 (95% CI 1.28 to 109.01)) following MMR+MenC+PCV. Coadministration of MMR+PCV led to more fever (RIR 1.91 (95% CI 1.83 to 1.99)), neurological events (RIR 2.04 (95% CI 1.67 to 2.49)) and rash (RIR 1.06 (95% CI 1.01 to 1.11)) compared with separate administration, DTaP/IPV/Hib+MMR to more musculoskeletal events (RIR 3.56 (95% CI 1.21 to 10.50)) and MMR+MenC to more fever (RIR 1.58 (95% CI 1.37 to 1.82)). There was no indication that unscheduled coadministrations are less safe than scheduled coadministrations.

CONCLUSION

Real-life RIRs of AEFI justify coadministering routine childhood vaccines according to the immunisation schedule. Further research into the severity of AEFI following coadministration is required for a complete understanding of the burden of these AEFI.

Subcutaneous vaccine administration - an outmoded practice

Subcutaneous vaccine (SC) administration is an outmoded practice which complicates vaccine administration recommendations. Local adverse events following immunization (AEFIs) are a recognized determinant of vaccine hesitancy/refusal which can lead to an increased prevalence of vaccine-preventable disease.

This extensive narrative review provides high-grade evidence that intramuscular (IM) administration of all vaccine types [adjuvanted, live virus and non-adjuvanted (inactivated whole cell, split cell and subunit)] significantly reduces the likelihood of local adverse events. This, combined with moderate grade evidence that IM injection generates significantly greater immune response compared with SC injection, allows a strong recommendation to be made for the IM injection of all vaccines except BCG and Rotavirus.

This will simplify vaccination practice, minimize the inadvertent misadministration of vaccines and potentially improve public trust in vaccination.

A second dose of a measles-mumps-rubella vaccine administered to healthy four-to-six-year-old children: a phase III, observer-blind, randomized, safety and immunogenicity study comparing GSK MMR and MMR II with and without DTaP-IPV and varicella vaccines co-administration

In many countries, a second dose of a combined measles, mumps, and rubella (MMR) vaccine is recommended at 4-6 years of age - similarly to the booster of diphtheria, tetanus, acellular pertussis, and inactivated polio vaccine (DTaP-IPV) and the second dose of varicella vaccine (VV). Vaccine co-administration is generally encouraged if no interferences exist among the vaccines. This phase IIIa, randomized, controlled trial (NCT01621802) evaluated the immunogenicity and safety of MMR-RIT (Priorix, GSK) when given as a second dose with or without co-administration of DTaP-IPV and VV, using MMR II (M-M-R II, Merck & Co Inc.) as comparator. Antibody geometric mean concentrations or titers (GMCs/GMTs) and response rates to the components of all the administered vaccines were assessed. Solicited, unsolicited, and serious adverse events were recorded. Four thousand eleven children aged 4-6 years were enrolled. MMR-RIT elicited immune responses that were not inferior to those of MMR II in terms of GMCs and seroresponse rates when administered alone or when co-administered with DTaP-IPV and VV. The immune responses to the co-administered vaccines in MMR-RIT recipients were non-inferior to those in MMR II recipients. MMR-RIT and MMR II demonstrated similar reactogenicity profiles; the most frequent solicited adverse events across vaccine groups and sub-cohorts were local pain and fever. In conclusion, the immunogenicity and safety profiles of MMR-RIT administered with or without DTaP-IPV and VV were similar to those of MMR II.

Post-marketing surveillance to assess the safety and tolerability of a combined diphtheria, tetanus, acellular pertussis and inactivated poliovirus vaccine (DTaP-IPV) in Korean children

Infanrix-IPV (GSK, Belgium) is a diphtheria, tetanus, acellular pertussis, and inactivated poliovirus combination vaccine (DTaP-IPV) licensed in many countries including Korea. In accordance with Korean regulations, we conducted a post-marketing surveillance (PMS) to evaluate the safety of DTaP-IPV administered to Korean children in routine immunization schedules. Children aged <7 years receiving at least one dose of DTaP-IPV either as part of a primary (3-dose) vaccination series or as a subsequent booster were enrolled. Adverse events (AEs), adverse drug reactions (ADRs) and serious AEs (SAEs) were recorded after each dose during the 30-day post-vaccination follow-up period. Among a total of 639 children, 289 subjects (45.2%) experienced AEs, mostly (79.2%) assessed as being unlikely to be related to the vaccination. ADRs were reported in 13.0% of subjects. Fever was the most commonly reported expected AE (11.9% of subjects) and also the most commonly reported expected ADR (8.5% of subjects). No obvious association between AE incidence and vaccine dose sequence was apparent. An unexpected AE was seen in 32.9% of children, and unexpected ADRs were far less common (1.9%). Thirty-four SAEs were recorded in 26 subjects (4.1%), in two of whom a causal association with the vaccine could not be excluded, although both resolved quickly. Data from this PMS indicate that DTaP-IPV has an acceptable safety profile when given to Korean children in accordance with local prescribing recommendations in routine childhood immunization. ClinicalTrials.gov identifier: NCT01568060

Transiently increased IgE responses in infants and pre-schoolers receiving only acellular Diphtheria-Pertussis-Tetanus (DTaP) vaccines compared to those initially receiving at least one dose of cellular vaccine (DTwP) - Immunological curiosity or canary in the mine?

BACKGROUND

Several previous studies have highlighted the strong Th2-polarising and IgE-promoting activity of the DTaP vaccine, but there is no evidence that this has pathological consequences and accordingly there is no current interest amongst vaccine developers in reformulating DTaP to attenuate these properties. In light of an apparent resurgence in pertussis in many countries, and emerging evidence from other areas of paediatric immunology of IgE-mediated interference with host defence mechanisms, this issue requires more detailed clarification.

METHODS

We have re-evaluated the impact of DTaP-only versus mixed DTwP/DTaP vaccination on Th2-dependent "bystander" IgE responses in three cohorts of children under different priming conditions, encompassing both vaccine-targeted and unrelated antigens including food allergens.

RESULTS

We confirm the generalised IgE-trophic activity of the DTaP vaccine in pre-schoolers and demonstrate similar (albeit transient) effects in infants. We additionally demonstrate that use of an alternative mixed infant priming schedule encompassing an initial dose of DTwP significantly attenuates this property.

INTERPRETATION

Central to our interpretation of these findings are studies demonstrating: (i) mixed DTwP/DTaP priming improves resistance to pertussis disease and attenuates the IgE-stimulatory component of long term vaccine-specific memory; (ii) IgE-mediated mechanisms can interfere with innate antiviral immunity and accordingly exacerbate airway symptoms in infected children. These observations, taken together with the data presented here, suggest a plausible mechanistic link between baseline pertussis-specific IgE titres in DTaP vaccinees and susceptibility to pertussis disease, which merits testing. Retrospective IgE analyses on sera collected from children at the time of presentation with pertussis could resolve this issue.

Safety of diphtheria, tetanus, acellular pertussis and inactivated poliovirus (DTaP-IPV) vaccine

BACKGROUND

In 2008, a diphtheria, tetanus, acellular pertussis, and inactivated poliovirus combined vaccine (DTaP-IPV) was licensed for use in children 4 through 6 years of age. While pre-licensure studies did not demonstrate significant safety concerns, the number vaccinated in these studies was not sufficient to examine the risk of uncommon but serious adverse events.

OBJECTIVE

To assess the risk of serious adverse events following DTaP-IPV vaccination.

METHODS

The study was conducted from January 2009 through September 2012 in the Vaccine Safety Datalink (VSD) project. In the VSD, electronic vaccination and encounter data are updated and aggregated weekly as part of ongoing surveillance activities. Based on previous reports and biologic plausibility, eight potential adverse events were monitored: meningitis/encephalitis; seizures; stroke; Guillain-Barré syndrome; Stevens-Johnson syndrome; anaphylaxis; serious allergic reactions other than anaphylaxis; and serious local reactions. Adverse event rates in DTaP-IPV recipients were compared to historical incidence rates in the VSD population prior to 2009. Sequential probability ratio testing was used to analyze the data on a weekly basis.

RESULTS

During the study period, 201,116 children received DTaP-IPV vaccine. Ninety-seven percent of DTaP-IPV recipients also received other vaccines on the same day, typically measles-mumps-rubella and varicella vaccines. There was no statistically significant increased risk of any of the eight pre-specified adverse events among DTaP-IPV recipients when compared to historical incidence rates.

CONCLUSIONS

In this safety surveillance study of more than 200,000 DTaP-IPV vaccine recipients, there was no evidence of increased risk for any of the pre-specified adverse events monitored. Continued surveillance of DTaP-IPV vaccine safety may be warranted to monitor for rare adverse events, such as Guillain-Barré syndrome.

Parental reports of adverse events following simultaneously given dT-IPV and MMR vaccines in healthy 9-year-old children

In the Netherlands, children at 9 years of age receive a booster dT-IPV together with their second measles, mumps, and rubella (MMR) vaccination within the national immunization program. Safety is monitored continuously by enhanced passive surveillance. This population-based study was conducted to obtain more information on adverse events after vaccination at 9 years of age. Questionnaires on local and systemic reactions were distributed 1 and 3 weeks after vaccination, respectively, to parents of 1,250 healthy children who received their MMR and diphtheria, tetanus, and inactivated poliovirus injection (dT-IPV) vaccination as scheduled. Response to the questionnaires was 57.0% and 46.5%, respectively. Local reactions occurred in 86.5% of the children within 7 days after vaccination, more often at the dT-IPV (83.4%) than at the MMR site (32.7%). Pain was the most reported symptom (80.8% at the dT-IPV site; 29.1% at the MMR site). Systemic events occurred in 33.4% children within 7 days after vaccination, with headache as the most frequently reported (20.8%). Systemic events occurred in 20.8% children 8-21 days after vaccination. Children with local reactions at only the dT-IPV site had significantly more systemic events (19.3%) than those without local reactions (3.4%, p < 0.01). Such difference was not found for the MMR site. No serious adverse events were reported. Medical intervention was applied to 133 children (130 used analgesics and for three children the GP was consulted by phone). In conclusion, the frequency of reported local reactions is high, especially at the dT-IPV site, but all symptoms were transient. However, the use of reduced antigen content vaccines in association with the occurrence of adverse events is meaningful to explore. Furthermore, the overall rates are useful for monitoring variations in adverse events rates in the general population.

New Combination Vaccines: DTaP-IPV (Kinrix) and DTaP-IPV/Hib (Pentacel)

Objective:

To evaluate the clinical utility of diphtheria and tetanus toxoids and acellular pertussis adsorbed and inactivated poliovirus vaccine ([DTaP-IPV]; Kinrix) and diphtheria and tetanus toxoids and acellular pertussis adsorbed, Inactivated poliovirus and Haemophilus b conjugate (tetanus toxoid conjugate) vaccine ([DTaP-IPV/Hib]; Pentacel) in the schedule for pediatric immunizations.

Data Sources:

PubMed was searched (1966–April 2009) using the key words Kinrix and Pentacel. Subject headings included vaccines, combined; diphtheria-tetanus-pertussis vaccine; diphtheria-tetanus-acellular pertussis vaccines; poliovirus vaccine, inactivated; and Haemophilus influenzae type b polysaccharide vaccinetetanus toxin conjugate. The search was limited to English-language publications involving humans. Product labeling was obtained from GlaxoSmithKline and Sanofi Pasteur. The Centers for Disease Control and Prevention (CDC) Web site was searched for relevant recommendations published June 2008–October 2009.

Study Selection And Data Extraction:

Phase 2 and 3 clinical trials evaluating immunogenicity and safety of DTaP-IPV and DTaP-IPV/Hib were reviewed. Published trials were supplemented with abstracts, review articles, manufacturer product labeling, and CDC recommendations.

Data Synthesis:

DTaP-IPV is immunogenic compared to its component vaccines, with no effect of concomitantly administered measles, mumps, and rubella vaccine. Although injection site pain has occurred more with the combination vaccine, its use would reduce by 1 the number of injections given when a child is 4–6 years old. DTaP-IPV/Hib is immunogenic and safe compared to separate vaccines. Immunogenicity to 7-valent pneumococcal conjugate vaccine and hepatitis B (HepB) vaccine is not affected by concomitant administration. DTaP-IPV/Hib decreases injections by up to 7 when given at 2, 4, 6, and 15–18 months of age. It fits into the schedule more easily than DTaP-HepB-IPV (Pediarix), the other DTaP-containing combination vaccine indicated for the primary infant series.

Conclusions:

DTaP-IPV and DTaP-IPV/Hib combination vaccines are immunogenic and safe when given to infants and children. They reduce the number of required injections. Combination vaccines are encouraged to promote timely vaccination and complete immunization schedules.

Kinrix: a new combination DTaP-IPV vaccine for children aged 4-6 years

Combination vaccines allow the administration of multiple vaccine antigens without the need for multiple injections. Recently, a combined diphtheria toxoid, tetanus toxoid, acellular pertussis and inactivated poliomyelitis vaccine (DTaP-IPV), Kinrix, has been licensed in the USA for use as the fifth DTaP dose and fourth IPV dose in children 4-6 years of age. Clinical trials have shown Kinrix to be immunogenic in 4-6-year-old children, with a safety profile comparable with that of separate DTaP and IPV vaccination. The use of Kinrix reduces by one the number of injections required to provide this age group with all recommended immunizations. Strategies such as the use of combined vaccines can help to maintain high levels of coverage against diphtheria, tetanus, pertussis and poliomyelitis diseases.

Diphtheria-tetanus-acellular pertussis and inactivated poliovirus vaccines given separately or combined for booster dosing at 4-6 years of age

BACKGROUND

In the United States, diphtheria-tetanus-acellular pertussis (DTaP) and inactivated poliovirus (IPV) booster vaccinations are recommended for children 4-6 years of age. A combined DTaP-IPV vaccine is being developed, which would reduce by one the number of injections in this age group.

METHODS

Children 4-6 years of age were randomized (1:1:1:1) to receive booster vaccination with 1 of 3 combined DTaP-IPV lots plus the measles, mumps, and rubella vaccine (N = 3156 for pooled lots) or separate doses of DTaP + IPV + measles, mumps, and rubella vaccine (N = 1053). Immunogenicity was assessed in a subset of children (N = 1331). Safety (solicited and unsolicited symptoms) including detailed assessment of local swelling reactions, was assessed in all children.

RESULTS

Increases in antibody geometric mean concentrations/titers 1 month after vaccination were observed for the diphtheria, tetanus, acellular pertussis, and polio antigens. At least 92.2% of combined DTaP-IPV subjects and 92.6% of separate DTaP + IPV subjects had a postvaccination booster response for one or more DTaP antigens. Booster responses to one or more poliovirus antigens were observed in at least 96.6% of combined DTaP-IPV subjects and 92.8% of separate DTaP + IPV subjects. The combined DTaP-IPV vaccine was noninferior to separately administered DTaP and IPV vaccines with respect to DTaP antigen booster response rates and poliovirus antibody geometric mean titers ratios. Reporting of solicited local and systemic events was comparable between both groups.

CONCLUSIONS

The combination DTaP-IPV vaccine provided immunogenicity and reactogenicity that is comparable to separately administered DTaP and IPV vaccines, with the advantage of requiring one less injection.

Ultrasound examination of extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis immunization in preschool-aged children

OBJECTIVE

The aim of this study was to determine the site, extent, and resolution of tissue involvement when extensive limb swelling occurred in the injected limb for children who received diphtheria-tetanus-acellular pertussis or reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine at 4 to 6 years of age.

METHODS

Children who had experienced an injection site reaction at 18 months of age were assigned randomly to receive an intramuscular injection of either reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine or diphtheria-tetanus-acellular pertussis vaccine between 4 and 6 years of age. Children who developed extensive limb swelling were recruited for assessment by clinical examination; ultrasound studies of the affected and opposite (control) arms were performed 24 to 48 hours after immunization and 48 to 96 hours later.

RESULTS

Twelve children with extensive limb swelling were enrolled in the study. Ultrasound examinations demonstrated swelling of both the subcutaneous and muscle layers of the vaccinated arm. Ultrasound assessment showed that the swelling exceeded the clinical measurements of skin redness and swelling. Subcutaneous and muscle tissues expanded to 281% and 111% of the tissue thicknesses of the control arm, respectively. Repeat ultrasound examinations after 48 to 96 hours showed considerable resolution of muscle swelling, compared with subcutaneous tissue swelling. There was no significant difference in the extent of swelling detected between children who received diphtheria-tetanus-acellular pertussis vaccine and those who received reduced-antigen content diphtheria-tetanus-acellular pertussis vaccine.

CONCLUSION

Extensive limb swelling reactions after diphtheria-tetanus-acellular pertussis or reduced-antigen content booster immunizations involved swelling of subcutaneous and muscle tissues with swelling and duration more marked in subcutaneous tissue.

Immunogenicity and safety of a combined DTaP–IPV vaccine compared with separate DTaP and IPV vaccines when administered as pre-school booster doses with a second dose of MMR vaccine to healthy children aged 4–6 years

Combination vaccines represent one solution to the problem of increased numbers of injections during single clinic visits. A combined DTaP-IPV (Infanrix-IPV) vaccine has been developed for use as a pre-school booster. Four hundred healthy children aged 4-6 years previously primed with 4 doses of DTaP vaccine (Infanrix), 3 doses of poliovirus vaccine and 1 dose of MMR vaccine were randomized to receive single doses of either the combined DTaP-IPV vaccine or separate DTaP and IPV vaccines in a Phase II trial (DTaP-IPV-047). All children also received a second dose of MMR vaccine. Immunogenicity was assessed in serum samples taken before and 1 month after booster administration. Safety was actively assessed for 42 days post-vaccination. Non-inferiority of the DTaP-IPV vaccine to separate DTaP and IPV vaccines was demonstrated for all DTaP antigen booster response rates and poliovirus geometric mean titers of antibody ratios. Post-vaccination, > or =99.4% of children in both groups had seroprotective levels of anti-diphtheria and anti-tetanus antibodies (> or =0.1IU/mL) and seroprotective anti-poliovirus antibody titers (> or =1:8). All children in both groups were seropositive for measles, mumps and rubella antibodies, with similar post-vaccination geometric mean concentrations/titers. No significant differences were observed in the incidence of solicited local or general symptoms, unsolicited symptoms and serious adverse events between the two groups. This combined DTaP-IPV appeared safe and immunogenic when given as a booster dose at 4-6 years of age. The DTaP-IPV vaccine had no negative effect on the response to co-administered MMR vaccine, making it well-suited for use as a pre-school booster.

Safety and immunogenicity of a combined DTPa–IPV vaccine administered as a booster from 4 years of age: A review

A combined DTPa-IPV booster vaccine was administered as a 4th or 5th dose after DTPa or DTPw priming. Over 99% vaccines developed antibody levels considered to be protective to diphtheria, tetanus and poliovirus, and >95% mounted a response to acellular pertussis antigens. Rectal temperature >39.5 degrees C was observed in at most 3.2% of vaccinees. Swelling >50 mm occurred in 24% of DTPa-primed compared to 5.5% of DTPw-primed children. Large swelling involving the entire upper arm (extending to involve the elbow joint) was reported for up to 1.2% of DTPa-primed subjects, which is consistent with literature reports for other DTPa vaccines.