Principles of pediatric combination vaccines and practical issues related to use in clinical practice

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.

Strategies for overcoming protein and peptide instability in biodegradable drug delivery systems

The global pharmaceutical market has recently shifted its focus from small molecule drugs to peptide, protein, and nucleic acid drugs, which now comprise a majority of the top-selling pharmaceutical products on the market. Although these biologics often offer improved drug specificity, new mechanisms of action, and/or enhanced efficacy, they also present new challenges, including an increased potential for degradation and a need for frequent administration via more invasive administration routes, which can limit patient access, patient adherence, and ultimately the clinical impact of these drugs. Controlled-release systems have the potential to mitigate these challenges by offering superior control over in vivo drug levels, localizing these drugs to tissues of interest (e.g., tumors), and reducing administration frequency. Unfortunately, adapting controlled-release devices to release biologics has proven difficult due to the poor stability of biologics. In this review, we summarize the current state of controlled-release peptides and proteins, discuss existing techniques used to stabilize these drugs through encapsulation, storage, and in vivo release, and provide perspective on the most promising opportunities for the clinical translation of controlled-release peptides and proteins.

Real life hexavalent vaccination among children as a practical guide for public health professionals: Four years (from 2016 to 2019) of clinical practice in Sicily, Italy

Hexavalent (HV) vaccination is a priority for newborn protection and in Italy is included in the National Immunization Plan with a three doses cycle at 61, 121 and 301 days of age. A retrospective clinical study has been conducted to evaluate real life clinical practice of HV vaccination in the fourth most populous Italian Region. Data on the completion of the HV cycle, on the interchangeability between the two HV adopted in 2016-2017 (DTaP3-IPV-HB/Hib) and 2018-2019 (DTaP5-IPV-HB-Hib) and on the use above the established age, were collected in five Sicilian Local Health Authorities. Data showed an average 91.5% completion of the vaccination cycle at 24 months of age. The average age of administration was significantly higher in children who switched between the two hexavalent vaccines compared to those who completed the vaccination cycle with the same product (p-value <.01). Interchangeability with one or two doses of HV was also documented in 17.8% (2018) and 16% (2019) of vaccinated infants. Co-administration with other vaccines included in the Sicilian Vaccination Schedule was 85% with anti-pneumococcal vaccination and 65% with anti-rotavirus vaccination. Children vaccinated above recommended age (from 15 to >36 months) significantly after the introduction of mandatory vaccination in Italy (p-value <.001). This retrospective analysis will contribute to manage potential disruptions due to missed routine immunization opportunities, as the pandemic has caused, with strategies such as catch up above recommended age as well as interchangeability. Data could also help to demonstrate the need to optimize vaccine sessions through co-administration, that strongly contribute to increase vaccination coverage rates and respect of timing of vaccination schedules.

A combined DTaP-IPV vaccine (Tetraxim®/Tetravac®) used as school-entry booster: a review of more than 20 years of clinical and post-marketing experience

INTRODUCTION

Routine infant primary series and toddler booster vaccination are associated with waning of antibody levels over time, which can lead to an increased incidence of vaccine-preventable diseases. A diphtheria-tetanus-pertussis (DTP) booster vaccination at school-entry (aged 4-7 years) allows continued protection against these diseases and is included in many national immunization programs.

AREAS COVERED

The available immunogenicity and safety data from 6 clinical studies of a diphtheria-tetanus-acellular pertussis-inactivated poliovirus vaccine (DTaP-IPV [Tetraxim®]) used as a school-entry booster vaccination were identified using a PubMed search or on file at Sanofi. The studies spanned a 15-year period (1995-2010) and were performed in different populations using different study designs, so all data were reviewed descriptively (no meta-analyses were conducted). Additionally, post-marketing experience was reviewed.

EXPERT OPINION

Each vaccine antigen is highly immunogenic, and the safety profile of the vaccine is satisfactory. Post-marketing evaluations have shown the effectiveness of a school-age booster, particularly against increased pertussis disease incidence around the time of school entry and the associated risk of spreading the disease through contact with younger vulnerable infants. School-entry provides an ideal opportunity to implement DTaP-IPV vaccination to close the gap between waning immunity from the previous infant/toddler vaccination and future adolescent vaccination.

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.

Preferences of healthcare professionals regarding hexavalent pediatric vaccines in Italy: a survey of attitudes and expectations

Introduction

In Italy, three hexavalent pediatric vaccines are available: two are ready-to-use (RTU) as pre-filled syringes, while the third must be reconstituted (need-for-reconstitution [NFR]). The formulation is related to the vaccination timing, safety of preparation and administration, and possible errors in immunization. We surveyed Italian healthcare professionals (HCPs) experienced with RTU and NFR vaccines in order to investigate their opinions on key aspects of the vaccines.

Methods

In Q1 2018, a qualitative study, ethnographic observations and in-depth interviews were performed in public vaccination settings of three Italian Regions. Data on how the vaccination process was managed and perceptions about the value of the RTU formulation were collected. In Q2 2018, face-to-face interviews were carried out to explore the attitude and preferences of Italian HCPs from nine Regions, assessing advantages and disadvantages of the two formulations from a quantitative point of view. In Q3-Q4 data analysis was carried out, using both qualitative and quantitative methodologies.

Results

The first phase demonstrated the following advantages of the RTU versus the NFR formulation: time-saving, lower probability of needle contamination and needle stick incidents, better handling, simpler procedure, easier disposal of waste. For the survey, 149 HCPs were interviewed; 80% and 40%, respectively, were very satisfied with the RTU and NFR vaccine.

Conclusions

Our study demonstrated that HCPs prefer the RTU formulation, as it simplifies vaccinations, reduces preparation time and minimizes the risk of errors. This formulation also saves time that can be spent on more in-depth counseling.

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.

Stability of Vaccines

Vaccines are considered the most economical and effective preventive measure against most deadly infectious diseases. Vaccines help protect around three million lives every year, but hundreds of thousands of lives are lost due to the instability of vaccines. This review discusses the various types of instability observed, while manufacturing, storing, and distributing vaccines. It describes the specific stability problems associated with each type of vaccine. This review also discusses the various measures adopted to overcome these instability problems. Vaccines are classified based on their components, and this review discusses how these preventive measures relate to each type of vaccine. This review also includes certain case studies that illustrate various approaches to improve vaccine stability. Last, this review provides insight on prospective methods for developing more stable vaccines.

DTwP-HB-Hib: antibody persistence after a primary series, immune response and safety after a booster dose in children 18-24 months old

Background

The new combination of DTwP-HB-Hib vaccines has been developed in Indonesia following World Health Organization (WHO) recommendation and integrated into national immunization program. The aims of the study were to measure 1) antibody persistence 12–18 months after a primary series, 2) immune response and safety after a booster dose of DTwP-HB-Hib.

Methods

This was a multi-center, open-labeled, prospective, interventional study. Subjects who had received complete primary dose of DTwP-HB-Hib vaccine from the previous phase III trial were recruited in this trial. Subjects were given one dose of DTwP-HB-Hib (Pentabio®) booster at age 18–24 months old. Diphtheria, tetanus, pertussis, hepatitis B, Hemophilus influenza type B antibodies were measured before and after booster to determine antibody persistence and immune response. Vaccine adverse events were assessed immediately and monitored until 28 days after the booster recorded with parent’s diary cards.

Results

There were 396 subjects who completed the study. Increased proportion of seroprotected subjects from pre-booster to post-booster were noted in all vaccine antigens: 74.5 to 99.7% for diphtheria; 100 to 100% for tetanus; 40.4 to 95.5% for pertussis; 90.2 to 99.5% for hepatitis B; and 97.7 to 100% for Hib. Common systemic adverse events (AEs) were irritability (23.7–25%) and fever (39.9–45.2%). Local AEs such as redness, swelling, and induration were significantly less common in the thigh group (7.7, 11.3, and 7.1%) than in the deltoid group (28.9, 30.7, and 25%) (P < 0.001). Most AEs were mild and resolved spontaneously within three-day follow-up period.

Conclusions

Booster of DTwP-HB-Hib vaccine at age 18–24 months is required to achieve and maintain optimal protective antibody. The vaccine is safe and immunogenic to be used for booster vaccination.

Trial registration

NCT02095314 (retrospectively registered, March 24, 2014).

Adverse events following immunization with pentavalent vaccine: experiences of newly introduced vaccine in Iran

BACKGROUND

The most important factors that affect the incidence of vaccine-related complications are the constituent biological components of the vaccine, injection site reactions, age and sex. The aim of this study is to determine the incidence rate of adverse events following immunization with pentavalent vaccine (DTPw-Hep B-Hib (PRP-T) vaccine (pentavac) (adsorbed) is manufactured by Serum Institute of India ltd), which was introduced in Iran in November 2014. It is important to monitor vaccine-related adverse events because of the role of vaccine safety in immunization program success.

METHODS

This study was a mixed cohort study that included 1119 children less than 1 year of age. In 2015, the children were referred to Hamadan health centers to receive pentavalent vaccine at 2, 4 and 6 months of age. The data were collected from the parents of the children using a questionnaire that was administered either face-to-face or by telephone. The cumulative incidence of side effects and risk ratio was reported with 95% confidence intervals (CI). Chi-squared tests and logistic regressions were used to investigate the association between the variables.

RESULTS

The cumulative incidence rate of pentavalent-related adverse events during 48 h following immunization was estimated to be 15.8% for swelling, 10.9% for redness, 44.2% for pain, 12.6% for mild fever, 0.1% for high fever, 20.0% for drowsiness, 15.0% for loss of appetite, 32.9% for irritability, 4.6% for vomiting and 5.5% for persistent crying. There is no evidence for the occurrence of convulsion and encephalopathy among children who receive pentavalent vaccines.

CONCLUSION

Further large studies with long time follow up are required to address rare events include convulsions, encephalopathy or persistent crying. However, Findings urge immunization programs to use pentavalent vaccinations and to continue implementing the current immunization program in children under 1 year of age.

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.

Is hepatitis B birth dose vaccine needed in Africa?

This commentary describes the need for a birth dose monovalent hepatitis B virus (HBV) vaccine and an effective programme for the prevention of mother-to-child-transmission (MTCT) of HBV in Africa. Current World Health Organization guidelines recommend routine maternal screening for HBV followed by treatment of highly infectious HBV-infected mothers, and HBV birth dose vaccination and the administration of hepatitis B immunoglobulin for HBV-exposed infants as an effective strategy for the prevention of HBV MTCT. None of these practices are currently in place in most parts of Africa. To date, fewer than 10 African countries vaccinate children at birth against HBV. Despite the hurdles associated with implementing this practice, its expansion to the rest of Africa is feasible and crucial to reducing the global number of new HBV infections by 90% by 2030, as targeted by the current Global Health Strategy for the elimination of viral hepatitis.

Highlights from the 3rd international HIV/viral hepatitis Co-infection meeting - HIV/viral hepatitis: improving diagnosis, antiviral therapy and access

The International AIDS Society convened the 3rd International HIV/Viral Hepatitis Co-Infection Meeting on 17 July 2016 as part of the pre-conference program preceding the 21st International AIDS Conference held in Durban, South Africa. The meeting brought together a diversity of scientific, technical and community interests to discuss opportunities and challenges for increased prevention, diagnosis and treatment of viral hepatitis in people living with HIV, particularly in low- and middle-income settings. The objectives of the meeting were:i.To review the latest therapeutic developments in viral hepatitis;ii.To identify challenges such as high cost of medications for hepatitis C virus (HCV) and risk of developing viral resistance, and successes, such as the provision of HCV treatment in community-based settings, movements to reduce drug costs and increasing access, in relation to scaling up diagnosis, screening, antiviral treatment and prevention of viral hepatitis;iii.To advance the agenda for elimination of viral hepatitis as a public health problem. Discussions centred around the six key interventions outlined by the World Health Organization Global Health Sector Strategy on Viral Hepatitis 2016-2021: hepatitis B virus (HBV) vaccination (including birth dose); safe injection practices plus safe blood; harm reduction among people who inject drugs; safer sex practices; hepatitis B treatment; and hepatitis C cure. This article summarizes the main issues and findings discussed during the pre-conference meeting. One of the recommendations from the meeting delegates is universal implementation of birth dose vaccination for HBV without further delay to prevent mother-to-child transmission of infection. There is also the need to implement screening and treatment of hepatitis among pregnant women. A call was made for concerted efforts to be put together by all stakeholders towards addressing some of the structural barriers, including criminalization of drug use, discrimination and stigma that people living with viral hepatitis face. Finally, the need for greater advocacy was highlighted to enable access to therapy of viral hepatitis at lower cost than currently prevails. Implementation of these resolutions will help in achieving the target of eliminating viral hepatitis as a public health threat.

Analysis of safety data in children after receiving two doses of ProQuad® (MMRV)

BACKGROUND

In randomized clinical studies, over 11,800 children, 12 months to 6 years of age, were administered ProQuad(®), a combination measles, mumps, rubella, and varicella vaccine (MMRV). This paper describes the safety following a 2-dose regimen of MMRV administered to children in the second year of life.

METHODS

Safety data from five clinical studies were combined for all children who were scheduled to receive two doses of MMRV ∼3-6 months apart. All vaccinated children were followed for safety following each dose of MMRV.

RESULTS

Of 3112 children who received a first dose of MMRV, 2780 (89.3%) received a second dose of MMRV. Overall, 70.5% and 57.7% of children reported ≥1 adverse experiences following first and second doses of MMRV, respectively. Injection-site redness was statistically significantly higher postdose 2 than postdose 1, while injection-site pain/tenderness was statistically significantly higher postdose 1 compared to postdose 2. Rashes were statistically significantly lower postdose 2 compared to postdose 1. Ten febrile seizures (8 postdose 1, 2 postdose 2) were reported following MMRV vaccination. The incidence of febrile seizures postdose 1 of MMRV was 0.26% (8/3019) compared to 0.07% (2/2695) postdose 2 of MMRV.

CONCLUSIONS

Administration of two doses of MMRV has an acceptable safety profile in children 12 to 23 months of age. There is a small increase in the risk of febrile seizures following the first dose of MMRV as compared to the component vaccines, but the risk for any individual child is relatively low.

Comparison of acellular pertussis-tetanus-diphtheria vaccines and whole-cell pertussis-tetanus-diphtheria vaccines in infancy

BACKGROUND

In clinical trials, diphtheria, tetanus and acellular pertussis vaccines have been shown to be less reactogenic than whole-cell combination vaccines.

AIM

To evaluate diphtheria and tetanus toxoids combined with acellular pertussis (DTaP) and diphtheria and tetanus toxoids combined with whole-cell pertussis (DTwP) with regard to local, systemic and febrile reactions.

METHODS

This prospective study was undertaken in 2008 when DTwP was replaced by DTaP in Turkey. The study population included infants of 2 (n = 1231), 4 (n = 1294), 6 (n = 1324) and 18 (n = 734) months of age who had received DTaP or DTwP vaccines between 2003 and 2008. Local, systemic and febrile adverse events were monitored by parental observation and recorded on a diary card.

RESULTS

Altogether, 1422 children were vaccinated, 45·2% of whom were male. 4583 doses of DtaP and 198 of DTwP were administered. Local, systemic and febrile reactions were more commonly observed in infants who received DTwP vaccines than in those who received DTaP vaccines (9·09% vs 0·85%, 12·12% vs 1·00% and 26·26% vs 2·58%, respectively, P<0·001). Infants who received DTaP vaccines at 2 months of age had systemic reactions (n = 24, 1·9%) more frequently than those at 4 (n = 12, 0·92%, P<0·001), 6 (n = 8, 0·6%, P<0·001) and 18 months of age (n = 1, 0·13%, P<0·001). Infants who received DTaP vaccination at 4 months of age had febrile reactions (n = 52, 4%) more often than those at 2 (n = 21, 1·7%, P<0·001), 6 (n = 37, 2·7%, P<0·001) and 18 months of age (n = 6, 0·81%, P<0·001). No difference in local reactions associated with number of vaccines was observed in the DTaP group. There was no significant difference in the rates of local, systemic and febrile reactions between the different age groups of children who received DTwP.

CONCLUSIONS

DTaP vaccines were found to have fewer local, systemic and febrile reactions than DTwP vaccines.

A combined diphtheria, tetanus, five-component acellular pertussis, poliovirus andHaemophilus influenzaetype b vaccine

Ideally, combination vaccines should not only be safe and effective, but also integrate smoothly into the vaccination schedule and provide advantages over the use of separately administered vaccines. Pentaceltrade mark (Sanofi Pasteur Ltd., Toronto, Canada), a combination vaccine first licensed in Canada and subsequently in other countries, is immunogenic against diphtheria, tetanus, pertussis, polio and Haemophilus influenzae type b when administered at 2, 4, 6 and 15-18 months of age. In published studies, the safety, immunogenicity and effectiveness of this combination vaccine were comparable with those of separately administered vaccines, with the advantage of a simplified dosing schedule.

Comparative immunogenicity and safety of different multivalent component pertussis vaccine formulations and a 5-component acellular pertussis vaccine in infants and toddlers: a randomized, controlled, open-label, multicenter study

BACKGROUND

Pentavalent and quadrivalent combination vaccine formulations from the same manufacturer (DTaP-IPV/Hib [PENTA], DTaP-IPV [QUAD]) were investigated as to whether they were sufficiently interchangeable to tailor use to local preference or availability.

METHODS

A randomized, controlled, open-label, 4-armed, multicenter study in healthy, full-term infants (42-89 days of age) was conducted in 38 centers across the United States. Participants were randomized 1:1:1:1 to a control vaccine group (3 doses DTaP, IPV, and Hib and at Dose 4 DTaP and Hib) and 3 combination vaccine groups: (1) 3 doses PENTA, then Dose 4 DTaP and Hib; (2) 4 QUAD doses and Hib; (3) 4 PENTA doses. Participants (N=2167) were immunized at 2, 4, and 6 months of age, Dose 4 participants (N=1832) at 15 months of age. Immunogenicity was assessed before Doses 1 and 4 and after Doses 3 and 4. Safety was assessed 30 days after each dose and through 180 days Post-Dose 4.

RESULTS

Antibody responses and geometric mean concentrations/geometric mean titers (GMCs/GMTs) elicited by each combination vaccine were noninferior (upper-bound 90% confidence interval of GMC/GMT ratios <1.5) to control vaccines except pertactin GMCs were higher after 4 control DTaP doses (157.46 EU/mL) than after Dose 4 with DTaP and Hib (after a PENTA infant series) (111.70 EU/mL) and after 4 PENTA doses (98.00 EU/mL). Fever rates in the combination vaccine groups were noninferior (upper bound 95% CI of combination vaccine group fever rate minus control vaccine group fever rate <10%) to the control vaccine group except the rate after 4 QUAD and Hib doses (23.5%) was higher than after 4 control DTaP doses (13.9%).

CONCLUSIONS

PENTA and QUAD had similar safety profiles and no clinically important differences in immunogenicity compared with separately administered control vaccines. ClinicalTrials.gov (NCT ID: NCT00255047).

Immunogenicity and safety of an investigational hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-hepatitis B-Haemophilus influenzae B conjugate combined vaccine in healthy 2-, 4-, and 6-month-old Argentinean infants

BACKGROUND AND AIMS

Assessment of a new, fully liquid, investigational hexavalent DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim, Sanofi Pasteur), containing the same active ingredients as Pentaxim (DTaP-IPV//PRT-T) and 10 μg Hansenula polymorpha-derived recombinant hepatitis B (Hep B) surface antigen, Sanofi Pasteur, in Argentinean infants.

METHODS

Infants born to Hep B surface antigen seronegative mothers were randomized to receive the DTaP-IPV-Hep B-PRP-T vaccine or Pentaxim and Engerix B Pediatrico (Hep B monovalent) vaccines at 2, 4, 6 months of age. Antibody titers were measured before and 1 month after 3-month primary vaccination. Noninferiority analyses were performed on seroprotection/seroconversion rates. Safety was evaluated descriptively up to 1 month after primary vaccination.

RESULTS

A total of 624 participants were enrolled, 312 participants were randomized to each group, and 604 participants completed the trial. The DTaP-IPV-Hep B-PRP-T vaccine was demonstrated as noninferior to the Pentaxim and Hep B monovalent vaccines with seroprotection/seroconversion rates 1 month postdose 3 for each valence. The anti-Hep B geometric mean titer 1-month postdose 3 for the investigational DTaP-IPV-Hep B-PRP-T primary series was similar to the monovalent Hep B control. The overall incidence of adverse events was similar among the 2 groups.

CONCLUSIONS

The new, fully liquid, investigational DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim) is highly immunogenic and safe when compared with licensed comparators, warranting further development.

Combination vaccines

The combination of diphtheria, tetanus, and pertussis vaccines into a single product has been central to the protection of the pediatric population over the past 50 years. The addition of inactivated polio, Haemophilus influenzae, and hepatitis B vaccines into the combination has facilitated the introduction of these vaccines into recommended immunization schedules by reducing the number of injections required and has therefore increased immunization compliance. However, the development of these combinations encountered numerous challenges, including the reduced response to Haemophilus influenzae vaccine when given in combination; the need to consolidate the differences in the immunization schedule (hepatitis B); and the need to improve the safety profile of the diphtheria, tetanus, and pertussis combination. Here, we review these challenges and also discuss future prospects for combination vaccines.

The immunogenicity and safety of a reduced PRP-content DTPw-HBV/Hib vaccine when administered according to the accelerated EPI schedule

Background

Combination vaccines improve coverage, compliance and effectively introduce new antigens to mass vaccination programmes. This was a phase III, observer-blind, randomized study of GSK Biologicals diphtheria-tetanus-whole cell pertussis vaccine combined with hepatitis B and Haemophilus influenzae type b vaccines, containing a reduced amount of polyribosyl-ribitol-phosphate (PRP) and a DTPw component manufactured at a different site (DTPw-HBV/Hib_2.5 [Kft]). The primary aim of this study was to demonstrate that DTPw-HBV/Hib_2.5 [Kft] was not inferior to the licensed DTPw-HBV/Hib (Tritanrix(tm)-HepB/Hiberix(tm)) vaccine or the DTPw-HBV/Hib_2.5 vaccine, also containing a reduced amount of PRP, with respect to the immune response to the PRP antigen, when administered to healthy infants, according to the Expanded Programme for Immunization (EPI) schedule at 6, 10 and 14 weeks of age.

Methods

299 healthy infants were randomised to receive either DTPw-HBV/Hib_2.5 [Kft] DTPw-HBV/Hib_2.5 or DTPw-HBV/Hib according to the 6-10-14 week EPI schedule. Blood samples were analysed prior to the first dose of study vaccine and one month after the third vaccine dose for the analysis of immune responses. Solicited local and general symptoms such as pain, redness and swelling at the injection site and drowsiness and fever, unsolicited symptoms (defined as any additional adverse event) and serious adverse events (SAEs) were recorded up to 20 weeks of age.

Results

One month after the third vaccine dose, 100% of subjects receiving DTPw-HBV/Hib_2.5 [Kft] or DTPw-HBV/Hib and 98.8% of subjects receiving DTPw-HBV/Hib_2.5 vaccine had seroprotective levels of anti-PRP antibodies (defined as anti-PRP antibody concentration ≥0.15 μg/ml). Seroprotective antibody concentrations were attained in over 98.9% of subjects for diphtheria, tetanus and hepatitis B. The vaccine response rate to pertussis antigen was at least 97.8% in each group. Overall, the DTPw-HBV/Hib_2.5 [Kft] vaccine was well tolerated in healthy infants; no SAEs were reported in any group.

Conclusions

The DTPw-HBV/Hib_2.5 [Kft] vaccine was immunogenic and well-tolerated when administered according to the EPI schedule to Indian infants.

Trial registration

http://www.clinicaltrials.gov NCT00473668

Epidemiology of pertussis and Haemophilus influenzae type b disease in Canada with exclusive use of a diphtheria-tetanus-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b pediatric combination vaccine and an adolescent-adult tetanus-diphtheria-acellular pertussis vaccine: implications for disease prevention in the United States

BACKGROUND

During the decade 1998-2007, a combination DTaP(5)-IPV/Hib vaccine was used exclusively in Canada to immunize infants and young children against diphtheria, tetanus, pertussis, polio, and invasive Haemophilus influenzae type b (Hib) disease.

METHODS

Medline was used to search for publications during 1996-2008 related to the epidemiology and vaccine prevention of pertussis and invasive Hib disease in Canada. Related abstracts and presentations were reviewed, when available, and epidemiologic data since 1985 were obtained from the Public Health Agency of Canada public Web site.

RESULTS

Reports of pertussis have declined substantially in preschool and school-aged children during the past decade, and cyclical peaks in disease incidence have been blunted or eliminated. In provinces and territories where Tdap(5) vaccine has been administered to 14- to 16-year-olds, marked reductions of pertussis have been documented in adolescents as well as younger age groups, possibly due to herd immunity. Incidence rates of invasive Hib disease among Canadian children <5 years declined markedly after introduction of Hib conjugate vaccines, and the disease has remained under control with exclusive use of DTaP(5)-IPV/Hib vaccine. Most cases of invasive Hib disease occur among unimmunized or only partially vaccinated children. The reduction of Hib case reports has been documented throughout Canada, including among Aboriginal children who are at high risk for this disease.

CONCLUSIONS

The Canadian experience with DTaP(5)-IPV/Hib and Tdap(5) vaccines is relevant to the United States because immunization schedules, vaccination coverage rates, and epidemiologic patterns of pertussis and Hib diseases are similar in the 2 countries, and because both vaccines are licensed for use in the United States.

Concomitant use of the 3-dose oral pentavalent rotavirus vaccine with a 3-dose primary vaccination course of a diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio-Haemophilus influenzae type b vaccine: immunogenicity and reactogenicity

BACKGROUND

The pentavalent rotavirus vaccine (PRV), RotaTeq, can be concomitantly administered with most routine childhood vaccines. This study evaluated the immunogenicity and reactogenicity of PRV when used concomitantly with a hexavalent vaccine containing diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus, and Haemophilus influenzae type b.

METHODS

Healthy infants (N = 403) received hexavalent vaccine concomitantly with either PRV or placebo at 2, 3, and 4 months of age. Antibody responses were measured immediately before and 42 +/- 3 days after vaccination. Parents/legal guardians recorded all adverse events for 14 days after vaccination.

RESULTS

Seroprotective titers for hepatitis B (hepatitis B surface antigen > or =10 mIU/mL) were achieved by 97.8% of subjects in both vaccine treatment groups. Seroprotective titers to H. influenzae type b (polyribosylribitol phosphate > or =0.15 microg/mL) were achieved by 91.4% of subjects receiving both vaccines and 95.1% of subjects receiving only hexavalent vaccine. Seroprotective titers to diphtheria, tetanus, and poliovirus were also comparable between the vaccine treatment groups, as were geometric mean antibody titers to the pertussis antigens. Among PRV recipients, 92% had a > or =3-fold rise in serum antirotavirus immunoglobulin A levels. Concomitant administration was well tolerated. The incidence of adverse events was similar for both groups, with no statistically significant increases in fever, vomiting, diarrhea, or irritability.

CONCLUSIONS

In this study, concomitant administration of PRV with hexavalent vaccine was well tolerated and the immune responses to the antigens of the hexavalent vaccine were noninferior when compared with those of the control group. In addition, PRV was immunogenic when administered concomitantly with hexavalent vaccine.

Safety and immunogenicity of a pentavalent vaccine compared with separate administration of licensed equivalent vaccines in US infants and toddlers and persistence of antibodies before a preschool booster dose: a randomized, clinical trial

OBJECTIVE

Our goal was to compare the safety and immunogenicity of a combination vaccine (DTaP(5)-IPV-Hib; Pentacel) with that of its separately administered, US-licensed equivalent vaccines (diphtheria, tetanus, 5-component acellular pertussis vaccine [DTaP(5); Daptacel], inactivated poliovirus vaccine [IPV; IPOL], and Haemophilus influenzae type b [Hib] vaccine [ActHIB]), when administered to infants and toddlers concomitantly with other routinely recommended vaccines and to assess antibody persistence from the fourth dose in toddlers to the fifth (preschool) DTaP(5) dose.

SUBJECTS AND METHODS

In this randomized, multicenter study, 1939 healthy infants were immunized at 2, 4, and 6 months of age with 1 of 3 lots of DTaP(5) coadministered with IPV and Hib vaccines or 1 lot of DTaP(5)-IPV-Hib combination vaccine. Subsequently, 849 of these study participants were given a fourth dose of DTaP(5) and Hib vaccines or a fourth dose of DTaP(5)-IPV-Hib at 1 to 16 months of age. Safety was monitored throughout the study, and blood specimens were obtained to assess antibody responses.

RESULTS

DTaP(5)-IPV-Hib elicited similar or fewer solicited injection-site and systemic reactions as compared with the separate administration of US-licensed DTaP(5), IPV, and Hib vaccines. Seroresponse and seroprotection rates elicited by DTaP(5)-IPV-Hib were noninferior to US-licensed equivalent vaccines after the infant series and after the fourth dose. Children immunized with DTaP(5)-IPV-Hib had higher antibody geometric mean concentrations to pertussis toxoid and filamentous hemagglutinin; children immunized with the separate vaccines had higher responses to pertactin. Hib antibody responses to Hib polysaccharide were nearly identical in the DTaP(5)-IPV-Hib and separate-vaccine groups. Persistence of antibodies to the fifth (preschool) dose was also similar between groups.

CONCLUSIONS

DTaP(5)-IPV-Hib combination vaccine was shown to be immunogenic and well tolerated. No clinically important differences in the safety or immunologic profiles were noted for DTaP(5)-IPV-Hib versus the separately administered, US-licensed equivalent vaccines. DTaP(5)-IPV-Hib is a suitable replacement for separately administered DTaP, IPV, and Hib vaccines.

Societal impact of combination vaccines: experiences of physicians, nurses, and parents

Crowded immunization schedules can result in missed or delayed dosing. Combination vaccines help immunize children on time, limit the required number of injections, and allow new vaccines to be added to the schedule. In the United States, a pentavalent vaccine combining diphtheria, tetanus toxoids, and acellular pertussis (DTaP), recombinant hepatitis B (HepB), and inactivated poliovirus vaccine (IPV) is available. Here, we describe the findings of informal surveys among providers, nurse managers, business managers, and parents on their attitudes toward and experiences with the DTaP-HepB-IPV vaccine. Combination vaccine use is expected to increase as more become available and awareness of their benefits grows.

Vaccine-preventable haemophilus influenza type B disease burden and cost-effectiveness of infant vaccination in Indonesia

BACKGROUND

Most of Asia, including Indonesia, does not use Haemophilus influenzae type b (Hib) conjugate vaccines. We estimated total vaccine-preventable disease burden and the cost-effectiveness of Hib conjugate vaccine in Indonesia.

METHODS

Hib pneumonia and meningitis incidences for children with access to health care were derived from a randomized vaccine probe study on Lombok Island, Indonesia during 1998-2002. Incidences were adjusted for limited access to care. Health system and patient out-of-pocket treatment cost data were collected concurrent with the probe study. For Hib vaccine in monovalent and combined (with DTP-HepB) presentations, we used 2007 UNICEF vaccine prices of US$3.30 and $3.75 per dose.

RESULTS

For the 2007 Indonesian birth cohort, Hib vaccine would prevent meningitis in 1 of every 179 children, pneumonia in 1 of every 18 children, and 4.9% of mortality among those younger than 5 years. The total incremental societal costs of introducing Hib vaccine in monovalent and pentavalent presentations were, respectively, US$11.74 and $8.93 per child vaccinated. Annual discounted treatment costs averted amounted to 20% of pentavalent vaccine costs. For the pentavalent vaccine, the incremental costs per discounted death and disability adjusted life-year averted amounted to US$3102 and $74, respectively, versus $4438 and $102 for monovalent vaccine.

CONCLUSIONS

Routine infant Hib vaccination would prevent a large burden of pediatric illness and death in Indonesia. Even without external funding support, Hib vaccine will be a highly cost-effective intervention in either a monovalent or pentavalent presentation based on commonly used benchmarks.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Modulation of immune response induced by co-administration of DNA vaccine encoding HBV surface antigen and HCV envelope antigen in BALB/c mice

Plasmid DNA vaccines encoding the hepatitis B virus (HBV) surface and hepatitis C virus (HCV) envelope antigens, respectively, were constructed, and attempt were made to find the possibility of a divalent vaccine against HBV and HCV. The expression of each plasmid in Cos-1 cells was confirmed using immunocytochemistry. To measure the induced immune response by these plasmids in vivo, female BALB/c mice were immunized intramuscularly with 100 microg of either both or just one of the plasmids. Anti-HBV and HCV-specific antibodies and related cytokines were evaluated to investigate the generation of both humoral and cellular immune responses. As a result, specific anti-HBV and anti-HCV serum antibodies from mice immunized with these plasmids were observed using immunoblot. The levels of IL-2 and RANTES showing a Th1 immune response were significantly increased, but there was no change in the level of IL-4 (Th2 immune response) in any of the immunized groups. Compared with each plasmid DNA vaccine, the combined vaccine elicited similar immune responses in both humoral and cell-mediated immunities. These results suggest that the combined DNA vaccine can induce not only comparable immunity experimentally without antigenic interference, but also humoral and Th1 dominant cellular immune responses. Therefore, they could serve as candidates for a simultaneous bivalent vaccine against HBV and HCV infections.

Sense and the science of childhood immunization: Can we achieve more with less?

The threat of biological terrorism with small pox virus and a global influenza pandemic in the face of limited vaccine supply recently stimulated research into the evaluation of fractional dose vaccine regimens, with promising immunogenicity results. While this approach is not new, it has been less applied to vaccines for less sensational but nevertheless, significant killer diseases. This manuscript provides an overview of the basics of immunization as it applies to the current practice of immunization in children, comments on the untapped avenues for cost reduction of vaccine delivery, and the potential for saving more lives with currently available resources.

The impact of DTaP-IPV-HB vaccine on use of health services for young infants

BACKGROUND

In 2003, a pentavalent vaccine (diphtheria, tetanus and acellular pertussis, injectable polio and hepatitis B) was introduced into the childhood vaccination schedule. A premarketing study showed a higher incidence of fever than with the vaccines administered separately. Because fevers in young infants prompt medical evaluations, this study examines the impact of this vaccine (DTaP-IPV-HB) on subsequent use of health services.

METHODS

We compared use of health services among 6- to 10-week-old infants receiving DTaP-IPV-HB (n = 1776) with a historical control receiving the prior schedule (n = 2162) at an inner-city practice network. Data sources included a hospital immunization registry and medical records. Outcome measures were visits to the emergency department and ambulatory practices, fever, tests, antibiotics and hospitalizations. Outcomes were stratified by age (<8, 8-10 weeks) and days since vaccination (3, 7).

RESULTS

Infants vaccinated with DTaP-IPV-HB were more likely to visit the ED (1.2% versus 0.6%, P = 0.03) and receive tests (47.6% versus 8.3%, P = 0.03) within 3 days of vaccination compared with the controls. Multivariate analysis showed infants vaccinated with DTaP-IPV-HB had a 7-fold increased risk of receiving a full sepsis workup and a 3-fold increased risk of receiving antibiotics within 7 days of vaccination. Medical evaluations decreased over time after implementation of the DTaP-IPV-HB vaccine. Concurrently, the rate of vaccination for infants <8 weeks markedly dropped.

CONCLUSIONS

The DTaP-IPV-HB vaccine was associated with increased use of health services in the emergency department, but these associations lessened over time. These findings reveal a conflict between the obligation of timely and efficient vaccination with the medical management of febrile young infants.

An adolescent and adult formulation combined tetanus, diphtheria and five-component pertussis vaccine

Pertussis causes substantial morbidity among adolescents and adults, as well as other persons in contact with affected individuals. In the context of widespread childhood immunization, vaccination of adolescents and adults is a relatively new strategy for reducing the disease in all age groups. ADACEL is a tetanus-diphtheria-acellular pertussis combination vaccine (incorporating pertussis toxoid, filamentous hemagglutinin, pertactin and fimbriae type 2 and 3 antigens) formulated for use in adolescents and adults based on similar products designed for infants and children. ADACEL vaccine is approved for use in Australia, Canada, Germany and the USA, and has been demonstrated to induce robust immune responses and acceptable levels of reactogenicity in clinical trials. Surveillance data from Canada, where ADACEL vaccine has been used in adolescents and adults in conjunction with ongoing childhood vaccination for several years, indicate an enhanced overall reduction in pertussis disease.

Prevention of pertussis across the age spectrum through the use of the combination vaccines PENTACEL™ and ADACEL™

Acellular pertussis-containing combination vaccines are widely used in the developed world for the control of pertussis and have been successful in controlling disease in preschool-aged children. Combination vaccines formulated for use in adolescents and adults have been developed more recently and are increasingly being implemented for the control of pertussis in these age groups. One such family of products is PENTACEL (Haemophilus influenzae type b conjugate vaccine reconstituted with component pertussis vaccine and diphtheria and tetanus toxoids adsorbed combined with inactivated poliomyelitis vaccine, DTaP-IPV-Hib), for use in young children, and ADACEL (tetanus and diphtheria toxoids adsorbed combined with component pertussis vaccine, dTap) for use in adolescents and adults. These products have been demonstrated to be safe, immunogenic and effective for the control of pertussis and the other included diseases.

Interchangeability of two diphtheria and tetanus toxoids, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b conjugate vaccines as a fourth dose in 15–20-month-old toddlers

BACKGROUND

Since 1998, all children in Canada have been immunized with a pentavalent diphtheria and tetanus toxoids, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b conjugate vaccine (DTaP-IPV-Hib) produced by one manufacturer (Pentacel). Recently, another DTaP-IPV-Hib (Infanrix-IPV-Hib) became available. Data on the interchangeability of these products was lacking.

METHODS

In this multicentered, observer-blind study, healthy 15-20-month-old children previously immunized with three doses of Pentacel were randomly allocated to receive a single dose of Pentacel or Infanrix-IPV-Hib. Adverse events were documented by diary for 7 days post-immunization and unsolicited adverse events were documented for 30 days.

RESULTS

433 participants were enrolled (mean age 17.1 months). Rates of fever, anorexia and irritability were similar in both groups. Injection-site redness >20 mm (11.5% versus 5.6%; p = 0.038), injection-site pain (52.1% versus 39.4%; p = 0.009) and moderate or greater drowsiness (13.8% versus 7.4%; p = 0.042) were more common after Pentacel than Infanrix-IPV-Hib. The proportions of participants who were sero-protected or who sero-responded were similar for all antigens. Geometric mean titers or concentrations were similar for antibodies against diphtheria toxoid and poliovirus type 3. Geometric mean concentrations or titers were higher in the Infanrix-IPV-Hib group against pertussis toxin (88.5 EU/mL versus 65.6 EU/mL), filamentous hemagglutinin (207.3 EU/mL versus 132.1 EU/mL), pertactin (251.9 EU/mL versus 166.9 EU/mL) and poliovirus type 1 (1293.7 versus 976.2 reciprocal dilution). Geometric mean titers or concentrations were higher in the Pentacel group against H. influenzae type b (29 microg/mL versus 19 microg/mL), tetanus toxoid (5.6 IU/mL versus 4.7 IU/mL) and poliovirus type 2 (1437.3 versus 1134.2 reciprocal dilution).

CONCLUSIONS

A booster dose of Infanrix-IPV-Hib after three priming doses of Pentacel is well-tolerated and immunogenic in 15-20-month-old toddlers and can be used interchangeably.

Do changes in policy affect vaccine coverage levels? Results of a national study to evaluate childhood vaccination coverage and reasons for missed vaccination in Italy

To evaluate the impact of actions taken in Italy since 1998 to improve vaccination coverage, a national EPI-survey was performed in 2003. Overall, 4602 children aged 12-24 months participated in the study; coverage was calculated for three doses of DT, polio, HBV, pertussis, and Hib, and for one dose of MMR/measles vaccine for children > or =16 months of age. Since 1998, when the last national survey was conducted, DT, polio, and HBV coverage have remained consistently high (95%), while pertussis, Hib, and MMR/measles significantly increased. Pertussis coverage reached the 95% target, and Hib is close to target (87%). Improving MMR coverage (77%), however, remains a national priority.

Calendario vacunal de la Asociación Española de Pediatría: recomendaciones 2004

The Vaccine Assessment Committee of the Spanish Association of Pediatrics discusses vaccine developments in 2003 and recommends some modifications to the vaccination schedule. The recommendation of substituting the oral polio vaccine for the inactivated polio vaccine, suppressing the fifth dose, is maintained. The introduction of the conjugate pneumococcal vaccine and the varicella vaccine is stressed. Concerning the meningococcal C vaccine, the improvement introduced by being able to immunize with just two doses is discussed. In agreement with the information received from the European Medicines Agency, there appear to be no well-founded reasons to abandon hexavalent preparations.

Combined hepatitis B vaccines

The status and likely impact of existing and potential new combined hepatitis B vaccines were broadly considered at the Viral Hepatitis Prevention Board (VHPB) meeting in Malta, October 2001. The currently available and/or licensed combined hepatitis B vaccines in Europe and the prospects for further such vaccines were reviewed. Data on the safety, immunogenicity, and European licensing status and availability of haxavalent vaccines combining hepatitis B (HepB), Haemophilus influenza type b (Hib), diphtheria, tetanus, and pertussis (acellular) (DTPa), and inactivated poliovirus (IPV) antigens were presented. Finally, the impact of the availability of combined hepatitis B vaccines on hepatitis B immunisation programmes in Europe were examined and the added value of combined hepatitis B vaccines globally was estimated.