In silico comparative study of SARS-CoV-2 proteins and antigenic proteins in BCG, OPV, MMR and other vaccines: evidence of a possible putative protective effect

Background

Coronavirus Disease 2019 (COVID-19) is a viral pandemic disease that may induce severe pneumonia in humans. In this paper, we investigated the putative implication of 12 vaccines, including BCG, OPV and MMR in the protection against COVID-19. Sequences of the main antigenic proteins in the investigated vaccines and SARS-CoV-2 proteins were compared to identify similar patterns. The immunogenic effect of identified segments was, then, assessed using a combination of structural and antigenicity prediction tools.

Results

A total of 14 highly similar segments were identified in the investigated vaccines. Structural and antigenicity prediction analysis showed that, among the identified patterns, three segments in Hepatitis B, Tetanus, and Measles proteins presented antigenic properties that can induce putative protective effect against COVID-19.

Conclusions

Our results suggest a possible protective effect of HBV, Tetanus and Measles vaccines against COVID-19, which may explain the variation of the disease severity among regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-021-04045-3.

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

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

Integration of hexavalent diphtheria, tetanus, acellular pertussis, hepatitis B virus, inactivated poliomyelitis and Haemophilus influenzae type b conjugate vaccine within existing national recommendations following a birth dose of monovalent hepatitis B virus vaccine: results of a systematic review in the Asia Pacific region

Introduction: In Asia Pacific, most countries recommend a monovalent hepatitis B virus (HBV) vaccine dose at birth followed by primary vaccination series including three or four doses of combination vaccines against diphtheria, tetanus, and pertussis, with or without Haemophilus influenzae type b (Hib), HBV or poliomyelitis antigens. If hexavalent conjugate vaccines against diphtheria-tetanus-acellular pertussis-HBV-inactivated poliovirus-Hib (DTPa-HBV-IPV/Hib) replace the vaccines included in the primary vaccination series, co-administration of lower-valent vaccines would be avoided but infants would receive ≥4 doses of HBV-containing vaccines before the age of 2 years. Areas covered: We searched for clinical trials conducted in the South-East Asia and Western Pacific Regions (World Health Organization geographic definition), investigating vaccination regimens with >3 doses of HBV-containing vaccines in infants, including a monovalent HBV vaccine birth dose and ≥1 dose of GSK's hexavalent DTPa-HBV-IPV/Hib vaccine. Expert opinion: The six clinical trials included in this review showed that infants who received the monovalent HBV vaccine at birth and three or four doses of DTPa-HBV-IPV/Hib vaccine achieved protective immunogenic titers with a clinically acceptable safety profile. Our results support the integration of hexavalent DTPa-HBV-IPV/Hib vaccine within existing national recommendations in the Asia Pacific region to reduce the number of injections during infancy.

Antibody persistence in pre-school children after hexavalent vaccine infant primary and booster administration

Objective: Antibody persistence evaluation for all antigens of a fully liquid DTaP-IPV-HB-PRP~T vaccine at 3.5 and 4.5 y of age following different primary series and booster schedules in South Africa and Latin America.

Methods: Participants had completed one of two previous studies (Study 1-South Africa; Study 2-Latin America). In Study 1, participants who had not received HB vaccine at birth received a 6–10-14 week primary series of DTaP-IPV-HB-PRP~T or DTwP/PRP~T-Hib+HB+OPV and a third group who had received HB vaccine at birth received a 6–10-14 week primary series of DTaP-IPV-HB-PRP~T; all received a booster (15–18 months) of the primary series vaccine(s) except for HB in the DTwP/PRP~T-Hib group. In Study 2, participants received HB vaccine at birth, a 2–4-6 month primary series of DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T, and a DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T booster (12–24 months). Participants were followed up at 3.5 and 4.5 y of age for antibody persistence.

Results: Approximately 80% of eligible participants were assessed. In Study 1, a birth dose of HB increased anti-HBs persistence (≥10 mIU/mL) following DTaP-IPV-HB-PRP~T primary and booster vaccination from 76.3% to 96.1% at 3.5 y of age and from 73.3% to 96.1% at 4.5 y of age; in Study 2, anti-HBs persistence was high and similar in each group. For the other antigens, there were no differences between groups or studies at 3.5 or 4.5 y.

Conclusion: Good persistence of antibodies to each antigen in the DTaP-IPV-HB-PRP~T vaccine up to pre-school age, irrespective of the vaccination schedule during the first 2 y of life.

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

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

Immunogenicity and Reactogenicity of DTPa-HBV-IPV/Hib and PHiD-CV When Coadministered With MenACWY-TT in Infants: Results of an Open, Randomized Trial

BACKGROUND

This study evaluated the immunogenicity and reactogenicity of a combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus virus-Haemophilus influenzae type b vaccine (DTPa-HBV-IPV/Hib) and a 10-valent pneumococcal conjugate vaccine (PHiD-CV) coadministered with a quadrivalent meningococcal conjugate vaccine (MenACWY-TT) in infants/toddlers.

METHODS

In this open, controlled, phase III study (NCT01144663), 2095 healthy infants were randomized (1:1:1:1) into 4 groups to receive MenACWY-TT at 2, 3, 4 and 12 months of age or MenACWY-TT, MenC-CRM197, or MenC-TT at 2, 4 and 12 months of age. All participants received PHiD-CV and DTPa-HBV-IPV/Hib at 2, 3, 4 and 12 months of age. Immunogenicity of DTPa-HBV-IPV/Hib was evaluated in exclusive randomized subsets of 25% of participants from each group postprimary, prebooster and postbooster vaccination, whereas immunogenicity of PHiD-CV was evaluated at all time points. Reactogenicity was evaluated on the total vaccinated cohorts during 8 days after each vaccination.

RESULTS

For each DTPa-HBV-IPV/Hib antigen, ≥97.2%, ≥76.5% and ≥97.9% of participants had seropositive/seroprotective levels 1 month postprimary vaccination, before the booster dose and 1 month postbooster, respectively. For each vaccine pneumococcal serotype, ≥74.0% of infants had antibody concentrations ≥0.35 μg/mL at 1 month postprimary vaccination, and robust increases in antibody geometric mean concentrations were observed from prebooster to postbooster. Redness was the most frequent solicited local symptom at the DTPa-HBV-IPV/Hib and PHiD-CV injection sites, reported after up to 47.7% and 57.0% of doses postprimary and postbooster vaccination, respectively.

CONCLUSIONS

Primary and booster vaccinations of infants/toddlers with DTPa-HBV-IPV/Hib and PHiD-CV coadministered with MenACWY-TT were immunogenic with clinically acceptable reactogenicity profiles. These results support the coadministration of MenACWY-TT with routine childhood vaccines.

Persistence of hepatitis B immune memory until 9-10 years of age following hepatitis B vaccination at birth and DTaP-IPV-HB-PRP∼T vaccination at 2, 4 and 6 months

OBJECTIVE

To evaluate the long-term persistence of anti-hepatitis B surface (HBs) antibodies and the response to a HB challenge re-vaccination in children who had received a primary series of DTaP-IPV-HB-PRP∼T (Hexaxim™) or DTaP-IPV-HB/PRP∼T (Infanrix hexa™).

METHODS

Two cohorts of participants who had previously received HB vaccine at birth followed by either DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T co-administered with PCV7 at 2, 4, 6 months of age in a randomized, Phase III, observer-blind study in Thailand, were followed up for anti-HBs antibodies (geometric mean concentrations [GMCs] and seroprotection [SP] rate [% of participants with a titer ≥10 mIU/mL]) at 12-18 months of age and 9-10 years of age. A monovalent HB challenge re-vaccination was administered at 9-10 years of age and the anamnestic response was evaluated.

RESULTS

Anti-HBs GMCs and SP rates in the DTaP-IPV-HB-PRP∼T and DTaP-IPV-HB/PRP∼T groups were high and similar post-primary vaccination series (2477 mIU/mL and 99.5% and 2442 mIU/mL and 99.5%, respectively) and declined to a similar extent in each group at 12-18 months (154.5 mIU/mL and 90.8% and 162.3 mIU/mL and 96.5%, respectively). Antibody levels further declined at 9-10 years of age (13.3 mIU/mL and 49.3% and 8.0 mIU/mL and 42.9%) and a strong anamnestic response occurred in each group post-HB challenge re-vaccination (92.8% and 98.7%, respectively).

CONCLUSION

The kinetics of long-term anti-HBs antibody persistence were similar following a primary series of DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T. The response to a subsequent HB challenge re-vaccination was strong and similar in each group, demonstrating persisting immune memory.

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.

Immunogenicity and safety of 3-dose primary vaccination with combined DTPa-HBV-IPV/Hib in Indian infants

Multivalent combination vaccines have reduced the number of injections and therefore improved vaccine acceptance, timeliness of administration and global coverage. The hexavalent diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus/Haemophilus influenzae type b (DTPa-HBV-IPV/Hib; Infanrix hexa™) vaccine, administered according to various schedules, is widely used for the primary vaccination of infants worldwide. In the current publication, we are presenting the immunogenicity and safety of 3 doses of DTPa-HBV-IPV/Hib vaccine when administered to Indian infants. 224 healthy infants (mean age 6.8 weeks) were vaccinated at 6-10-14 weeks (W) of age (n = 112) or 2-4-6 months (M) of age (n = 112). One month after the third vaccine dose, the seroprotection/seropositivity status against diphtheria, pertussis, tetanus, polio, hepatitis B and Hib antigens ranged from 98.6% to 100% in both groups. The vaccine response rate to the pertussis antigens ranged from 97% to 100%. Pain (6-10-14W group: 25.2%; 2-4-6M group: 13.4%) and fever (15.3% and; 15.2%, respectively) were the most frequently reported solicited local and general symptoms. Unsolicited adverse events were reported for 35.7% (6-10-14W group) and 22.3% (2-4-6M group) of subjects. No vaccine related serious adverse events were reported. In conclusion, the hexavalent DTPa-HBV-IPV/Hib vaccine was immunogenic and well tolerated, irrespective of the dosing schedule.

Combination vaccines against diarrheal diseases

Diarrheal diseases remain a leading cause of global childhood mortality and morbidity. Several recent epidemiological studies highlight the rate of diarrheal diseases in different parts of the world and draw attention to the impact on childhood growth and survival. Despite the well-documented global burden of diarrheal diseases, currently there are no combination diarrheal vaccines, only licensed vaccines for rotavirus and cholera, and Salmonella typhi-based vaccines for typhoid fever. The recognition of the impact of diarrheal episodes on infant growth, as seen in resource-poor countries, has spurred action from governmental and non-governmental agencies to accelerate research toward affordable and effective vaccines against diarrheal diseases. Both travelers and children in endemic countries will benefit from a combination diarrheal vaccine, but it can be argued that the greater proportion of any positive impact will be on the public health status of the latter. The history of combination pediatric vaccines indicate that monovalent or single disease vaccines are typically licensed first prior to formulation in a combination vaccine, and that the combinations themselves undergo periodic revision in response to need for improvement in safety or potential for wider coverage of important pediatric pathogens. Nevertheless combination pediatric vaccines have proven to be an effective tool in limiting or eradicating communicable childhood diseases worldwide. The landscape of diarrheal vaccine candidates indicates that there now several in active development that offer options for potential testing of combinations to combat those bacterial and viral pathogens responsible for the heaviest disease burden—rotavirus, ETEC, Shigella, Campylobacter, V. cholera and Salmonella.

The value of childhood combination vaccines: From beliefs to evidence

Although vaccination is one of the most cost-effective health care interventions, under-vaccination and variation in coverage rates lower than policy targets is rising in developed countries, partly due to concerns about vaccination value and benefits. By merging various antigens into a single product, combination vaccines represent a valuable tool to mitigate the burden associated with the numerous injections needed to protect against vaccine preventable infectious diseases and increase coverage rate, possibly through various behavioral mechanisms which have yet to be fully explored. Beyond their cost-effectiveness in protecting against more diseases with fewer injections, combination vaccines also have several other benefits, for children, their parents/carers, as well as for the health system and the population as a whole. The objectives of this review are to identify and illustrate the value of combination vaccines for childhood immunization. Evidence was classified into 2 groups: benefits for society and benefits for public health and healthcare systems. This article also highlights the value of innovation and challenges of combination vaccine development as well as the need for an increased number of suppliers to mitigate the impact of any potential vaccine shortage. Increasing public confidence in vaccines and combination vaccines is also critical to fully exploit their benefits.

A randomized study to evaluate the immunogenicity and safety of a heptavalent diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, haemophilus influenzae b, and meningococcal serogroup C combination vaccine administered to infants at 2, 4 and 12 months of age

BACKGROUND

The immunogenicity and safety of the investigational diphtheria, tetanus, acellular pertussis, hepatitis B, poliomyelitis, Haemophilus influenzae type b (Hib) and meningococcal serogroup C (MenC) heptavalent combination vaccine were compared with those of licensed control vaccines.

METHODS

In this open, phase II, randomized study (NCT01090453), 480 infants from Germany, France and Canada received the heptavalent vaccine (Hepta group) or hexavalent and monovalent MenC control vaccines (HexaMenC group) co-administered with a 13-valent pneumococcal conjugate vaccine at 2, 4 and 12 months of age. Immunogenicity was measured 1 month after the second primary dose, and before and 1 month after the booster dose. Safety and reactogenicity were also evaluated.

RESULTS

Non-inferiority of immune responses to MenC and Hib induced by 2-dose primary vaccination with the heptavalent vaccine versus control vaccines was demonstrated. In exploratory analyses, postprimary and postbooster functional antibody geometric mean titers against MenC tended to be lower (1119.5 vs. 3200.5; 2653.8 vs. 6028.4) and antibody geometric mean concentrations against Hib higher (1.594 vs. 0.671 μg/mL; 17.678 vs. 13.737 μg/mL) in the Hepta versus the HexaMenC group. The heptavalent and control vaccines were immunogenic to all other antigens, although immune responses to poliovirus were lower than expected in both groups. No differences in safety and reactogenicity profiles were detected between groups.

CONCLUSIONS

The heptavalent vaccine induced non-inferior MenC and Hib responses compared with control vaccines. Both vaccination regimens, when administered at 2, 4 and 12 months of age, had comparable safety profiles and were immunogenic to all antigens, with lower-than-expected responses to poliomyelitis.

Booster vaccination: the role of reduced antigen content vaccines as a preschool booster

The need for boosters for tetanus, diphtheria, pertussis, and polio, starting from preschool age, is related to the waning immune protection conferred by vaccination, the elimination/reduction of natural boosters due to large-scale immunization programs, and the possibility of reintroduction of wild agents from endemic areas. Taking into account the relevance of safety/tolerability in the compliance with vaccination among the population, it have been assessed whether today enough scientific evidences are available to support the use of dTap-IPV booster in preschool age. The review of the literature was conducted using the PubMed search engine. A total of 41 works has been selected; besides, the documentation produced by the World Health Organization, the European Centre for Disease Control, and the Italian Ministry of Health has been consulted. Many recent papers confirm the opportunity to use a low antigenic dose vaccine starting from 4 to 6 years of age. There is also evidence that 10 years after immunization the rate of seroprotected subjects against diphtheria does not differ significantly between those vaccinated with paediatric dose (DTaP) or reduced dose (dTaP or dTap) product. The dTpa vaccine is highly immunogenic for diphtheria toxoids regardless of prior vaccination history (2 + 1 and 3 + 1 schedules).

A randomized, controlled trial to assess the immunogenicity and safety of a heptavalent diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, hib and meningococcal serogroup C combination vaccine administered at 2, 3, 4 and 12-18 months of age

BACKGROUND

Combination vaccines offer protection against multiple diseases with fewer injections. This study evaluated the immunogenicity and safety of an investigational diphtheria, tetanus, acellular pertussis, hepatitis B, poliomyelitis, Haemophilus influenzae type b (Hib) and meningococcal serogroup C (MenC) heptavalent combination vaccine (heptavalent vaccine) given as 4 doses at 2, 3, 4 and 12-18 months of age.

METHODS

In this randomized, open, phase II study (NCT00970307/NCT01171989) conducted in Poland, 421 infants were enrolled to receive the heptavalent vaccine or licensed comparator vaccines. Immunogenicity against study vaccine antigens was measured prior to and 1 month after primary and booster vaccinations. Safety and reactogenicity of the vaccines were also evaluated.

RESULTS

The primary noninferiority objectives of the MenC and Hib immune responses induced by the heptavalent vaccine versus comparator vaccines were reached after primary vaccination, but no statistical conclusion could be drawn after booster dose. One month after primary and booster vaccinations, ≥98.4% of the heptavalent vaccine recipients were seroprotected for MenC and Hib. Exploratory analyses indicated that the heptavalent vaccine induced higher postprimary vaccination antibody geometric mean concentrations against Hib, but lower postprimary and postbooster vaccinations geometric mean titers against MenC compared with the relevant comparator vaccines. The reactogenicity profiles of the vaccines were acceptable, although 1 infant vaccinated with the heptavalent vaccine experienced a serious adverse event (thrombocytopenia) considered possibly related to vaccination.

CONCLUSIONS

The heptavalent vaccine was immunogenic and had a clinically acceptable safety profile when administered to infants and toddlers.

An update after 16 years of hepatitis B vaccination in South Africa

Hepatitis B (HB) virus (HBV) infection is highly endemic with at least 65 million chronic HB surface antigen (HBsAg) carriers in Africa, 25% of whom are expected to die from liver disease. Before the introduction of the HB vaccine, the prevalence of chronic carriage of HBV in black South Africans was 9.6%, with 76% having been previously exposed to HBV. The major transmission route in South Africa is unexplained horizontal transmission between toddlers, with most transmission occurring before the age of 5 years. During adolescence and early adulthood, sexual transmission becomes the dominant route, while healthcare workers (HCWs) are also at risk for parenteral/percutaneous transmission during occupational exposures. In 1995 the South African Department of Health (SADoH) incorporated the HB vaccine, administered as a monovalent, into the Expanded Programme on Immunisation (EPI) at 6, 10, and 14 weeks of age, and studies conducted thereafter have found it to be safe and highly effective. Catch-up vaccination for adolescents was not introduced and there is no schools-based vaccination programme. The SADoH recommends HB vaccination of HCWs, but this is not mandatory and there is no national policy, thus HB vaccination uptake in HCWs is sub-optimal. Since 1995, studies on children have found that the prevalence of chronic HBsAg carriage has decreased, as has the incidence of paediatric hepatocellular carcinoma and HBV-related membranous nephropathy. The SADoH should focus their efforts on attaining a high infant HB vaccine coverage, prepare for introducing a HB birth dose, and consider using a hexavalent vaccine (DTaP-IPV-Hib-HepB). The department may also want to consider including targeted HB vaccination for 12 year-olds, if their Road to Health Cards show they were not vaccinated as infants. A national policy is needed for HCWs to ensure that they are fully vaccinated and protected against HBV infection.

DTPa-HBV-IPV/Hib vaccine (Infanrix hexa™): a guide to its use in infants

Infanrix hexa™, a diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliomyelitis, and Haemophilus influenzae type b (Hib) conjugate vaccine, is indicated for primary and booster vaccination of infants. Available clinical data from more than a decade of experience with the vaccine indicate that primary and booster vaccination with Infanrix hexa™ is a safe and useful option for providing protection against the common childhood diseases of diphtheria, tetanus, poliomyelitis, pertussis, hepatitis B, and disease caused by Hib.

DTaP(5)-IPV-Hib vaccine (Pediacel®)

Pediacel® is a fully liquid formulation of a diphtheria, tetanus, five-component acellular pertussis, inactivated poliovirus and Haemophilus influenzae type b combination vaccine, which does not require reconstitution. Both vial and prefilled syringe presentations of Pediacel® are available for use in the EU. In active-controlled clinical trials, primary and/or booster vaccination with Pediacel® was highly immunogenic, eliciting strong and sustained serologic responses against all its component toxoids/antigens when administered according to a variety of different schedules. In particular, pivotal studies showed that Pediacel® was generally similar and/or noninferior to reconstituted pentavalent and hexavalent diphtheria, tetanus, and acellular pertussis-based combination vaccines in terms of the seroprotection rates elicited against the diphtheria, tetanus, poliovirus, and Haemophilus influenzae type b components that these products have in common, as well as in terms of the seroresponse/booster response rates elicited against the acellular pertussis components that these products have in common. Differences in immune responses between Pediacel® and these vaccines were considered unlikely to be clinically significant. There was no clear evidence of clinically relevant changes in the immunogenicity of Pediacel® (or the coadministered vaccine) when given concomitantly with meningococcal group C conjugate, pneumococcal conjugate, or hepatitis B vaccines in clinical studies. Pediacel® was generally well tolerated and demonstrated low reactogenicity in clinical trials. It had an adverse event profile generally similar to that of other combination vaccines based on diphtheria, tetanus and acellular pertussis vaccine, including Infanrix®-IPV+Hib and Infanrix® hexa.