Disparate kinetics in immune response of two different Haemophilus influenzae type b conjugate vaccines: Immunogenicity and safety observations from a randomized controlled phase IV study in healthy infants and toddlers using a 2+1 schedule

Since the introduction of Haemophilus Influenzae type b (Hib) conjugate vaccines, invasive Hib disease has strongly declined worldwide, yet continued control of Hib disease remains important. In Europe, currently three different hexavalent combination vaccines containing Hib conjugates are marketed. In this phase IV, single-blind, randomized, controlled, multi-country study (NCT04535037), we aimed to compare, in a 2 + 1 vaccination schedule, the immunogenicity and safety and show non-inferiority, as well as superiority, of DTPa-HBV-IPV/Hib (Ih group) versus DTaP5-HB-IPV-Hib (Va group) in terms of anti-polyribosylribitol phosphate (PRP) antibody geometric mean concentrations (GMCs) and proportion of participants reaching anti-PRP antibody concentrations greater than or equal to a threshold of 5 µg/mL. One month after the booster vaccination, the anti-PRP antibody GMC ratio (Ih group/Va group) was 0.917 (95% CI: 0.710-1.185), meeting the non-inferiority criteria. The difference in percentage of participants (Ih group - Va group) reaching GMCs ≥5 µg/mL was -6.3% (95% CI: -14.1% to 1.5%), not reaching the predefined non-inferiority threshold. Interestingly, a slightly higher post-booster antibody avidity was observed in the Ih group versus the Va group. Both vaccines were well tolerated, and no safety concerns were raised. This study illustrates the different kinetics of the anti-PRP antibody response post-primary and post-booster using the two vaccines containing different Hib conjugates and indicates a potential differential impact of concomitant vaccinations on the anti-PRP responses. The clinical implications of these differences should be further studied.

Do Pentavalent (DTwP-Hib-HBV) vaccines have sex-differential nonspecific effects? An observational study

Vaccines may alter the ability to combat infections unrelated to the target disease, i.e. have "nonspecific effects." The non-live Diphtheria-Tetanus-Pertussis vaccine (DTP) has been associated with increased child mortality, especially for females. In 2008, the DTP-containing Pentavalent vaccine replaced DTP vaccine in Guinea-Bissau. We investigate female relative to male mortality after Penta vaccination. In Guinea-Bissau, Bandim Health Project (BHP) registered children's vaccination and vital status at biannual village visits and provided vaccines. Among children Penta-vaccinated by BHP, we compared mortality of males and females in Cox proportional hazards models. Children aged 6 weeks to 8 months entered the analysis at the date of vaccination and were followed for up to 6 months. Between September 2008 and December 2017, 33,989 children aged 6 weeks to 8 months were under surveillance. Of these 12,753 (females: 6,363; males: 6,390) received Penta by the BHP and entered the study contributing with 19,667 observations. The mortality rate following Penta vaccination was 25.2 per 1,000 person years for females and 26.6 for males, resulting in an adjusted Female/Male mortality rate ratio of (F/M aMRR) 1.01 (0.82-1.25). The association between sex and mortality differed by timeliness of vaccination, F/M aMRR: 0.62 (0.41-0.93) for children vaccinated below median age, and F/M aMRR: 1.38 (0.90-2.13) for children vaccinated above median age. We did not find higher overall mortality in females than males after Penta vaccination. Our findings suggest that mortality differences between males and females following Penta vaccination may depend on timeliness of Penta vaccination.

Postmarketing Safety Surveillance of a Hexavalent Vaccine in the Vaccine Adverse Event Reporting System

We assessed the safety of hexavalent vaccine diphtheria and tetanus toxoids and acellular pertussis, inactivated poliovirus, hepatitis b, and haemophilus influenzae b conjugate vaccine in the Vaccine Adverse Event Reporting System. Five hundred-one reports of adverse events (AEs) were identified; 21 (4.2%) were serious. Most frequently reported AEs were fever (10.2%) and injection site erythema (5.4%). AEs reported were consistent with findings from prelicensure studies.

Safety and immunogenicity of a new formulation of a pentavalent DTwP-HepB-Hib vaccine in healthy Indian infants-A randomized study

BACKGROUND

Pentavalent vaccines (DTP-HepB-Hib) have been introduced in many countries in their routine public immunization programmes to protect against diphtheria (D), tetanus (T), pertussis (P), hepatitis B (Hep B) and Hemophilus influenzae type b (Hib) diseases. This study compared the safety and immunogenicity of a new formulation of a whole-cell Bordetella pertussis (wP) based pentavalent vaccine (DTwP-HepB-Hib). The new formulation was developed using well-characterized hepatitis B and pertussis whole cell vaccine components.

METHODS

This was a phase III, observer-blind, randomized, non-inferiority, multi-center study conducted in India among 460 infants who were followed up for safety and immunogenicity for 28 days after administration of three doses of either investigational or licensed comparator formulations at 6-8, 10-12 and 14-16 weeks of age.

RESULTS

The investigational formulation of DTwP-HepB-Hib vaccine was non-inferior to the licensed formulation in terms of hepatitis B seroprotection rate (% of subjects with HepB antibodies ≥10mIU/mL were 99.1% versus 99.0%, respectively, corresponding to a difference of 0.1% (95% CI, -2.47 to 2.68)) and pertussis immune responses (adjusted geometric mean concentrations of antibodies for anti-PT were 76.7 EU/mL versus 63.3 EU/mL, with a ratio of aGMTs of 1.21 (95% CI, 0.89-1.64), and for anti-FIM were 1079 EU/mL versus 1129 EU/mL, with a ratio of aGMTs of 0.95 (95% CI, 0.73-1.24), respectively). The immune responses to other valences (D, T, and Hib) in the two formulations were also similar. The safety profile of both formulations was found to be similar and were well tolerated.

CONCLUSIONS

The investigational DTwP-HepB-Hib vaccine formulation was immunogenic and well-tolerated when administered as three dose primary series in infants.

CLINICAL TRIAL REGISTRATION

Clinical Trials Registry India number: CTRI/2018/12/016692.

Fixed drug eruption after pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus and Haemophilus influenzae type b combined vaccine in an infant

In Turkey, diphtheria-tetanus-acellular pertussis-inactivated poliovirus and Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine has been administered to all children in the second, fourth, sixth and 18th months within the scope of the national vaccination programme. Here we present a rare case of fixed drug eruption (FDE) that occurred as a result of the administration of a pentavalent DTaP-IPV-Hib combined vaccine in a 4-month-old girl. There was no history of taking any other medication before or when the lesion appeared. The lesion responded well to 1 week of topical methylprednisolone aceponate cream application and regressed within 1 week, leaving mild hyperpigmentation. Few cases of FDE have been reported occurring after administration of various vaccines and it is extremely rare in children. To our knowledge, this is the first reported case of FDE developing in an infant after the combined pentavalent DTaP-IPV-Hib vaccine.

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.

Persistence of Hepatitis B Immune Memory Until 6 Years of Age Following Hexavalent DTaP-IPV-HB-PRP~T Vaccination in a 3-, 5- and 11- to 12-month Schedule and Response to a Subsequent Hepatitis B Challenge Vaccination

Anti-hepatitis B (HBs) antibody persistence and hepatitis B challenge were evaluated at 6 years of age following vaccination of fully liquid DTaP-IPV-HB-PRP~T or reconstituted DTaP-IPV-HB//PRP~T at 3, 5, 11-12 months of age. At 6 years, 53.8% and 73.5% had seroprotective anti-HBs antibodies (≥10 mIU/mL), increasing to 96.7% and 95.9% postchallenge, confirming a strong anamnestic response in primed vaccinees.

Gene expression profiling reveals insights into infant immunological and febrile responses to group B meningococcal vaccine

Neisseria meningitidis is a major cause of meningitis and septicaemia. A MenB vaccine (4CMenB) was licensed by the European Medicines Agency in January 2013. Here we describe the blood transcriptome and proteome following infant immunisations with or without concomitant 4CMenB, to gain insight into the molecular mechanisms underlying post-vaccination reactogenicity and immunogenicity. Infants were randomised to receive control immunisations (PCV13 and DTaP-IPV-Hib) with or without 4CMenB at 2 and 4 months of age. Blood gene expression and plasma proteins were measured prior to, then 4 h, 24 h, 3 days or 7 days post-vaccination. 4CMenB vaccination was associated with increased expression of ENTPD7 and increased concentrations of 4 plasma proteins: CRP, G-CSF, IL-1RA and IL-6. Post-vaccination fever was associated with increased expression of SELL, involved in neutrophil recruitment. A murine model dissecting the vaccine components found the concomitant regimen to be associated with increased gene perturbation compared with 4CMenB vaccine alone with enhancement of pathways such as interleukin-3, -5 and GM-CSF signalling. Finally, we present transcriptomic profiles predictive of immunological and febrile responses following 4CMenB vaccine.

The Comparison of the Adverse Events of Pentavalent Vaccine and DPT Vaccine in 2-6 Months Infants in Iran: A National Study

Background

Vaccination is the most remarkable intervention in public health and is an effective strategy in controlling infectious diseases among infants.

Objectives

The aim of this study was to compare the adverse events of Pentavalent vaccine and DPT vaccine in two- to six-month-old infants in Iran.

Methods

This is an analytical cross-sectional study in which healthy infants aged two to six months, having received DPT vaccine in 2013 and Pentavalent vaccine in 2015, were studied for any experienced adverse events related to these vaccines. Percentage, mean, standard deviation and chi-square tests were used to describe and analyze the data (p < 0.05).

Findings

The results showed that 10,464 and 17,561 adverse events, which were associated with DPT vaccine and Pentavalent vaccine respectively, were recorded in the infants who received these vaccines throughout Iran. Mazandaran, Qazvin and Golestan provinces reported the highest number of adverse events, respectively (15.74%, 11.25%, and 9.12%). Moreover, Pentavalent vaccine seemed to have more recorded adverse events compared to DPT, high fever had the highest record rate for DPT vaccine (47.4%) and mild localized complications was the highest for Pentavalent vaccines (31.68%). There was a significant relationship between the kind of vaccine and the type of reaction, adverse event categorization and the country that produced the vaccine (p < 0.05).

Conclusion

Severe localized adverse events including high fever, vomiting, diarrhea and restlessness seemed to be less in Pentavalent vaccine compared to DPT vaccine. Therefore, substituting Pentavalent vaccine for DPT vaccine in infants seems to reduce the adverse events among them.

Early childhood vaccination and subsequent mortality or morbidity: are observational studies hampered by residual confounding? A Danish register-based cohort study

OBJECTIVES

To estimate the association between childhood vaccination and subsequent morbidity and mortality by adjusting for environmental and host factors. Further, to examine the degree of residual confounding in such observational studies.

DESIGN

Register-based cohort study including 1 122 929 Danish children.

PARTICIPANTS

All children born in Denmark in the period 1999-2016 who survived until 16 months of age without prior migration followed from 16 months until the first of the following: event of interest, migration, 5 years of age or 31 December 2016.

MAIN OUTCOME MEASURES

Adjusted HRs (aHRs) and absolute risks were calculated for the three outcomes: mortality, hospitalisation for infection and asthma using register data on deaths, specific hospital contacts and dispensed prescribed medication. The exposure was the combination of the routine vaccines against diphteria-tetanus-pertussis-polio-Haemophilus influenzae type b and measles-mumps-rubella (DTP and MMR in short) administered in early childhood. Hospitalisation due to accidents was analysed as a negative control outcome to examine residual confounding.

RESULTS

Children with 3DTP+MMR had a lower hazard of mortality than the reference group with 3DTP, adjusted HR (aHR)=0.45 (95% CI: 0.35 to 0.57), whereas the children with 1 or 2 DTP had higher hazards of dying, aHR=1.55 (95% CI: 1.14 to 2.13) and aHR=1.96 (95% CI: 1.34 to 2.89). The vaccination group 3DTP+MMR was associated with a reduced hazard of asthma aHR=0.94 (95% CI: 0.92 to 0.96). Also, the vaccination group 3DTP+MMR was associated with a reduced hazard of hospitalisation due to accidents, aHR=0.83 (0.80 to 0.85) compared with the reference group with 3 DTP.

CONCLUSIONS

The results suggested a beneficial impact of MMR on under-five mortality but did not support the hypothesis that DTP is detrimental, since the group of children with fewer DTP vaccinations experienced increased mortality. The results of the study may to some degree be prone to residual confounding since an unexpected association between MMR vaccination and hospitalisation for accidents was observed.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vaccine-induced immune thrombocytopaenia purpura in autologous haematopoietic stem cell transplantation

Immune Thrombocytopenia Purpura (ITP) secondary to vaccinations is rare, especially after autologous hematopoietic stem cell transplantation (HSCT). A 31-yearold female received autologous HSCT for relapsed Hodgkin Disease, with platelet engraftment at Day+14. One week after receiving second scheduled vaccinations, she developed severe thrombocytopenia (3x10⁹/L) associated with pharyngeal hematoma. Bone marrow (BM) examinations were consistent with ITP, possibly secondary to Influenza vaccine. Platelet increment was poor despite high dose corticosteroids, intravenous immunoglobulin (IVIG), Danazol and Eltrombopag. A repeated BM biopsy was in agreement with ITP. Re-treatment with tapering doses of prednisolone resulted in stable platelet counts at 120x10⁹/L a year later.

Differences by sex in IgG levels following infant and childhood vaccinations: An individual participant data meta-analysis of vaccination studies

BACKGROUND

If immune responses to vaccination differ between males and females, sex-specific vaccination schedules may be indicated. We systematically reanalysed childhood vaccination studies conducted in The Netherlands for sex-differences in IgG-responses. To assess the impact of potential sex-differences in IgG-responses, we explored sex-differences in vaccine failure/effectiveness and reactogenicity.

METHODS

Six studies with IgG-measurements for 1577 children following infant pneumococcal (PCV7/PCV10/PCV13) and/or DTaP-IPV-Hib(-HepB) vaccinations, or the pre-school DTaP-IPV booster were included. We performed one-stage individual participant data meta-analyses per time-point of the effect of sex on IgG levels against pneumococcal serotypes, diphtheria toxoid, tetanus toxoid, pertussis Ptx/FHA/Prn and Hib-PRP using linear mixed models. Using existing study data, we compared reactogenicity after PCV7/PCV10 and DTaP-IPV-Hib(-HepB) vaccination in girls and boys. Vaccine failure/effectiveness was compared between girls and boys for invasive pneumococcal disease (IPD), invasive Hib disease and pertussis using notification data.

RESULTS

For pneumococcal vaccination, the geometric mean concentration ratio of IgG levels in girls versus boys pooled across serotypes was 1.15 (95%CI 0.91-1.45) 1 month following the primary series, 1.16 (1.02-1.32) at age 8 months, 1.12 (1.02-1.23) pre-booster (age 11 months) and 0.99 (0.89-1.10) post-booster (age 12 months). Diphtheria toxoid, tetanus toxoid, pertussis Ptx/FHA/Prn and Hib-PRP IgG levels did not differ between girls and boys, except for Hib post-booster (1.24; 95%CI 1.01-1.52) and tetanus before pre-school booster (0.71; 0.53-0.95). We found no difference between boys and girls in reactogenicity at age 4 or 11 months or in vaccine failure/effectiveness for IPD, invasive Hib disease or pertussis.

CONCLUSION

For most vaccine antigens investigated, there were no consistent differences in vaccine-induced IgG levels. Vaccine-induced pneumococcal IgG levels were slightly higher in girls, but only between the primary series and the 11-month booster. These results, along with similar reactogenicity and vaccine failure/effectiveness, support the uniform infant vaccination schedule in the Dutch national immunisation programme.

Prophylactic antipyretics for prevention of febrile seizures following vaccination

Question Parents of a 12-month-old boy are bringing their son in to my family practice clinic for his well-baby visit. As the infant is due for his 12-month vaccine series, the parents are concerned after hearing about the association between certain vaccinations and an increased risk of febrile seizures, and are wondering if they should administer prophylactic antipyretics to decrease the risk of febrile seizure. What vaccinations are associated with increased risk of febrile seizure, and is there evidence supporting prophylactic administration of antipyretics to prevent febrile seizures? Answer Vaccinations associated with increased risk of febrile seizure include the following: the measles-mumps-rubella vaccine; the measles-mumps-rubella-varicella vaccine; the combined diphtheria, tetanus, acellular pertussis, polio, and Haemophilus influenzae type b vaccine; the whole-cell pertussis vaccine; the 7-valent pneumococcal conjugate vaccine; and concomitant administration of the trivalent inactivated influenza vaccine with either the 7-valent pneumococcal conjugate vaccine or the diphtheria, tetanus, and acellular pertussis vaccine. Despite being a higher-risk group, children receiving these vaccinations should not receive prophylactic antipyretics, as no statistically significant reduction in the rate of febrile seizures has been documented, and prophylactic antipyretic use potentially decreases the immune response to certain vaccines.

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.

Risk factors for adverse events after vaccinations performed during the initial hospitalization of infants born prematurely

INTRODUCTION

There are significant delays in implementing vaccination among preterm infants.

OBJECTIVES

Description of the frequency and kinds of adverse events following immunization in preterms. Establishment of the group of preterms who will distinctively be susceptible to adverse events.

MATERIALS AND METHODS

Demographical, clinical data and the occurrence of adverse events after DTaP, HIB and pneumococcal vaccination among preterms during their initial hospitalization were prospectively collected with the use of an electronic data form between 1st June 2011 and 31st May 2015. The analysis was conducted on 138 patients. The groups were divided according to maturity (I: ≤ GA 28w n=73 and GA 29-36 w n=65).

RESULTS

There were no statistically significant differences between the groups in the occurrence of adverse events. Out of the total group, following vaccination apnoea developed in 6 newborns (4%) and activity dysfunctions were observed in 13 newborns (10%). The occurrence of apnoea after vaccination positively correlated with the time of non-invasive ventilation and the occurrence of late infection. There were no statistically significant demographical or clinical risk factors for the development of activity dysfunctions following vaccination.

CONCLUSIONS

Term vaccination in clinically stable preterm infants is a safe medical procedure. However, long-term non-invasive respiratory support and late infections are risk factors for apnea following vaccinations. In these patients vaccinations should be considered during hospitalization.

IMMUNOGENICITY AND SAFETY OF QUINVAXEM® (DIPHTHERIA, TETANUS, WHOLE-CELL PERTUSSIS, HEPATITIS B AND HAEMOPHILUS INFLUENZAE TYPE B VACCINE) GIVEN TO VIETNAMESE INFANTS AT 2 TO 4 MONTHS OF AGE

Vietnam plans to replace the routine childhood diphtheria, pertussis and tetanus combination (DPT) vaccine with a pentavalent vaccine. The present study was performed to assess the immunogenicity and safety of the combined diphtheria, tetanus, whole-cell pertussis, hepatitis B (HepB), and Haemophilus influenzae type b (Hib) (DTwP-HepB-Hib) Quinvaxem® vaccine in children. A total of 131 infants received the Quinvaxem® vaccine at 2, 3 and 4 months. Antibody levels were measured at baseline, at one month after the third injection and one year after the first injection. Seroprotection rates were high for each vaccine antigen at one month after the third dose: 93.1% for diphtheria, 98.5% for tetanus, 99.2% for pertussis (seroconversion rate), 93.1% for HepB, and 100% for Hib (anti-PRP ≥ 0.15 µg/ml). The rate of children with protective antibodies persisting at one year after the first dose was 88.4% for diphtheria, 49.6% for pertussis, 82.2% for tetanus, 76.7% for HepB and 97.7% for Hib (anti-PRP ≥ 0.15 µg/ml). The Quinvaxem® vaccine was well tolerated and has a low rate of adverse events. Quinvaxem® given at 2, 3 and 4 months of age was immunogenic and safe for primary immunization among infants in Vietnam.

SAFETY OF A CRM197-CONJUGATED HAEMOPHILUS INFLUENZAE TYPE B VACCINE IN KOREAN CHILDREN

Haemophilus influenzae type b (Hib) is a major cause of meningitis and pneumonia with high morbidity and mortality rates in young children. The introduction of effective and well-tolerated conjugate Hib vaccines, has nearly eradicated this disease in many countries. We investigated the safety of the Hib PRP-CRM197 vaccine in a multi-center post-marketing surveillance (PMS) study. Korean children (N = 764) aged 1-33 months were enrolled when receiving a routine primary immunization or a booster vaccine with Hib PRP-CRM197 and solicited and unsolicited adverse events (AEs) were recorded using a diary card for 7 and 28 days after each vaccination, respectively. In this study, AEs were reported by 66% of subjects but were generally mild, with 42% of subjects reporting solicited AEs and 46% reporting unsolicited AEs. Among the unsolicited AEs, 98% were determined to be unrelated to the study vaccine. The studied Hib PRP-CRM197 vaccine was well tolerated by the study group and found to have a similar safety profile to that reported in other clinical studies. This vaccine is suitable for routine immunization against Hib disease among Korean children. AEs due to this vaccine will continue to be monitored.

[Evaluation of safety of haemophilus influenza type b(Hib) conjugate vaccine in postmarketing based on the immunization information management system]

OBJECTIVE

To analyze the occurrence feature of adverse events following immunization (AEFI) of Hib conjugate vaccine (HibCV) and to evaluate the safety of HibCV in postmarketing.

METHODS

2008-2013 HibCV AEFI data were collected through national AEFI information management system, which were downloaded in March 18, 2014.The demographic information and inoculation quantity of HibCV were from Immunization information management system in Jiangsu province. The incidence rate and 95% CI value of AEFI, common vaccine reaction and rare vaccine reaction following immunization of HibCV were calculated. The differences in the incidence rate of common vaccine reaction and rare vaccine reaction among sex, months of age, and number of injections were compared by means of (χ² tests.

RESULTS

A total of 6.16 million doses of vaccine were administered in Jiangsu province during 2008-2013, and 4 718 vaccinees reported having adverse event, for a rate of 76.60/100 000 (95% CI: 74.42/100 000-78.79/100 000). The incidence rate of common vaccine reaction and rare vaccine reaction was 71.10/100 000 (95% CI: 68.99/100 000-73.20/100 000) and 5.16/100 000 (95% CI: 4.60/100 000-5.73/100 000), respectively. The main symptoms of common vaccine reactions were fever, swelling, indurations and gastrointestinal reactions. The incidence rates of them were 40.54/100 000, 35.09/100 000, 12.94/100 000 and 0.36/100 000 in turn. The main symptoms of rare vaccine reactions were anaphylactic rashes and angioedema, the incidence rates of which were 4.77/100 000 and 0.15/100 000 respectively. 91.39% (4 002/4 379) of common vaccine reactions and 88.36% (281/318) of rare vaccine reactions happened within 1 d after vaccination. Anaphylactic shock (3 cases) and laryngeal edema (1 case) all happened within 1 d after vaccination. The incidence rate of common vaccine reactions among boys (79.72/100 000, 2 641/3 313 071) was higher than that of girls (61.07/100 000, 1 738/2 846 001) (χ² = 74.92, P < 0.001). The incidence rate of common vaccine reactions among children aged ≥ 12 month-old (86.82/100 000, 2 200/2 533 949) was higher than that among children aged 2-11 month-old (60.11/100 000, 2 179/3 625 123) (χ² = 149.79, P < 0.001). The incidence rate of common vaccine reactions in children vaccinated the first dose (78.93/100 000, 2 666/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (61.59/100 000, 1 713/2 781 458) (χ² = 64.59, P < 0.001). The incidence rate of rare vaccine reactions in children vaccinated the first dose (6.69/100 000, 226/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (3.31/100 000, 92/2 781 458) (χ² = 33.82, P < 0.001).

CONCLUSION

The safety of HibCV among children was relative good. However, the surveillance should still focus on the anaphylactoid reactions of anaphylactic shock and laryngeal edema after HibCV immunization.

A case-control study evaluating the relationship between thimerosal-containing haemophilus influenzae type b vaccine administration and the risk for a pervasive developmental disorder diagnosis in the United States

Thimerosal is an organic mercury (Hg)-containing compound (49.55 % Hg by weight) historically added to many multi-dose vials of vaccine as a preservative. A hypothesis testing case-control study evaluated automated medical records in the Vaccine Safety Datalink (VSD) for organic Hg exposure from Thimerosal in Haemophilus influenzae type b (Hib)-containing vaccines administered at specific times within the first 15 months of life among subjects diagnosed with pervasive developmental disorder (PDD) (n = 534) in comparison to controls. The generally accepted biologically non-plausible linkage between Thimerosal exposure and subsequent diagnosis of febrile seizure (n = 5886) was examined as a control outcome. Cases diagnosed with PDD received significantly more organic Hg within the first 6 months of life (odds ratio (OR) = 1.97, p < 0.001) and first 15 months of life (OR = 3.94, p < 0.0001) than controls, whereas cases diagnosed with febrile seizure were no more likely than controls to have received increased organic Hg. On a per microgram of organic Hg basis, cases diagnosed with a PDD in comparison to controls were at significantly greater odds (OR = 1.0197, p < 0.0001) of receiving increasing organic Hg exposure within the first 15 months of life, whereas cases diagnosed febrile seizure were no more likely than controls (OR = 0.999, p > 0.20) to have received increasing organic Hg exposure within the first 15 months of life. Routine childhood vaccination is an important public health tool to reduce the morbidity and mortality associated with infectious diseases, but the present study provides new epidemiological evidence of a significant relationship between increasing organic Hg exposure from Thimerosal-containing vaccines and the subsequent risk of PDD diagnosis in males and females.

Safety and immunogenocity of a novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroups A and C-tetanus-toxoid conjugate vaccine in healthy Chinese children aged 6 months to 5 years old

A novel combined Haemophilus influenzae type b-Neisseria meningitidis serogroups A and C-tetanus-toxoid conjugate vaccine (Hib-MenAC vaccine) has been developed to protect children against diseases caused by Hib, MenA, and MenC. This study investigated the safety and immunogenicity of the Hib-MenAC vaccine administered in 2-dose series to children aged 6-23 months and in a single dose to children aged 2-5 y. A randomized, positive-controlled, non-inferiority clinical trial was conducted for 1200 healthy participants in each age group. Within each age group, participants were randomly allocated to the Hib-MenAC group or the control group at a ratio of 1:1. Adverse reactions were recorded within 28 d after each dose. Blood samples were obtained to assess immunogenicity on day 0 and at 28 d after a complete vaccination course. For the investigational vaccine, the incidence of total adverse reactions in vaccinees aged 6-23 months was 46.8% and that in vaccinees aged 2-5 y was 29.8%. Most adverse reactions were mild or moderate. One non-fatal serious adverse event occurred in the Hib-MenAC group, but was unrelated to vaccination. The seroconversion rate to the 3 components reached 94.0%, and the proportion of vaccinees with rSBA titers ≥ 1:8 and PRP ≥ 0.15 g/mL reached 97.0% in both age groups. The safety and immunogenicity of the Hib-MenAC vaccine were non-inferior when compared to the licensed vaccines. It was concluded that the novel vaccine would be expected to protect children against all of the targeted diseases.

Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer

Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes in the manufacturing process and vaccine formulation, to start directly with phase 1 clinical trials.

Safety and Immunogenicity of a Pentavalent Combination Vaccine (Diphtheria, Tetanus, Acellular Pertussis, Polio and Haemophilus Influenzae Type b Conjugate) When Administered as a Fourth Dose at 15 to 18 Months of Age

A DTaP-IPV//PRP-T combination vaccine (Pentacel) has been universally used in Canada to provide immunization against diphtheria, tetanus, pertussis, polio, and Haemophilus influenzae type b with single injections at 2, 4, 6 and 18 months of age. This randomized, multicenter study was conducted to evaluate administration of a fourth dose of DTaP-IPV//PRP-T at 15 to 18 months of age, similar to the US immunization schedule. Participants who had received three doses of DTaP-IPV//PRP-T by 8 months of age were enrolled at 12 months and randomized to receive a fourth dose at 15, 16, 17 or 18 months. Antibody levels for each vaccine antigen were measured prior to and four weeks following booster vaccination. Overall, 1782 subjects were immunized and monitored for adverse events, and 735 were evaluated for immune responses. Preimmunization antibody levels differed minimally by age, for all antigens. The immune responses elicited by DTaP-IPV//PRP-T were comparable between participants vaccinated at 15 or 16 months and those vaccinated at 17 or 18 months, as demonstrated by specific antibody geometric mean titers, seroprotection/seroresponse rates, and reverse cumulative distribution curves. The fourth dose was well tolerated in all age groups. Toddlers at 15, 16, 17 or 18 months of age are equally suitable recipients for booster immunization with the DTaP-IPV//PRP-T vaccine.

A Retrospective Study on the Quality of Haemophilus Influenzae Type B Vaccines Used in the U.K. Between 1996 and 2004

Following the reduction in efficacy of Hib-TT vaccines in the primary immunization schedule observed in the UK between 1999 and 2003, batches of vaccine manufactured by two different companies were retrospectively examined by the National Institute for Biological Standards and Control. The study evaluated 41 batches of the Hib-TT vaccines manufactured between 1994 and 2003, assaying potency (total PRP saccharide content), integrity (% free saccharide), consistency (molecular sizing), and immunogenicity, as well as reviewing data previously obtained at the time of release. The study indicated the stability of the lyophilized final fill vaccines to extend well past their assigned shelf-lives, and found no trends in the endotoxin content, total saccharide or % free saccharide content. A trend towards slightly larger conjugates was observed over time in Hib-TT A, evidenced in both the manufacturer's data obtained at the time that samples were submitted for testing and in data obtained from the retrospective analysis. The study confirmed that that there had been no significant change in the quality of the Hib vaccines that could possibly account for the change reported in their protective efficacy in the UK. The study also demonstrated the value of independent testing of vaccines from the time of licensure and in the ongoing monitoring and re-examination of selected batches, as necessary, to assure their continuing quality, safety and consistency.

Lot-to-Lot Consistency of a Combined Hexavalent Diptheria-Tentanus-Acellular-Pertussis, Hepatitis B, Inactivated Polio and Haemophilus b Conjugate Vaccine, Adminstered to Healthy Chilean Infants at 2, 4 and 6 Months of Age

OBJECTIVES

To assess the safety, immunogenicity and lot consistency of a liquid hexavalent combined vaccine (DTaP-IPV-PRP approximately T-HBs, HEXAVAC) (Sanofi-Pasteur MSD, France) administered to infants at two, four and six months of age.

METHODS

A total of 1028 infants were vaccinated with one of three vaccine lots, in a randomized, double-blind fashion. Equivalence testing was used to compare post-vaccination seroprotection/seroconversion rates and geometric mean titers (GMTs) for each antigen between the three lots. Blood samples were drawn before vaccination and one month after the third dose. Local and systemic adverse events were monitored for three days following each injection.

RESULTS

Equivalence between lots was demonstrated for all antigens, on post-dose 3 seroprotection/seroconversion rates and GMTs. Reported rates of local and systemic adverse events tended to increase with subsequent doses. Altogether, 11.8% of the infants reported at least one adverse local event (mainly redness and induration/swelling) after the first dose and 36.1% after the third dose. Systemic adverse events (mainly irritability and fever) were reported by 39.2% of the infants after the first dose and by 57.5% after the third one.

CONCLUSION

Three separate lots of the liquid hexavalent combined vaccine induced consistently protective antibody responses against all antigens. These results and the well established clinical tolerability of this combined vaccine make it suitable for primary immunization of infants at two, four and six months of age.

Safety and Immunogenicity of Two Formulations of a Hexavalent Diphtheria-Tetanus-Acellular Pertussis-Inactivated Poliovirus-Haemophilus influenzaeb Conjugate-Hepatitis B Vaccine in 15 to 18 Month-Old Children

Combination vaccines decrease the number of injections and improve parental satisfaction and vaccination schedule compliance. In a phase 1, randomized, partially-blinded, single-dose booster study, we evaluated two formulations of an investigational liquid hexavalent vaccine containing diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate and hepatitis B surface antigen (DTaP-IPV-Hib-HBV) in 60 healthy toddlers, 15 to 18 months of age, who had been primed with three doses of a licensed pentavalent diphtheria, tetanus, acellular pertussis (5-component), inactivated poliovirus, Haemophilus influenzae b conjugate (DTaP-IPV//PRP-T) vaccine. The DTaP-IPV//PRP-T vaccine was used as a control in 30 subjects. The investigational formulations, which contained the same DTaP-IPV components, differed only in Hib (content and conjugate) and HBV (content) (PRP-T/HBV10 = 12 mug Hib tetanus toxoid conjugate with 10 microg HBsAg; PRP-OMPC/HBV15 = 6 microg Hib Neisseria meningitidis outer membrane protein complex with 15 microg HBsAg). Injection-site pain, redness and swelling were reported by 46.7%, 46.7%, and 20.0% of the licensed vaccine recipients, 43.3%, 43.3%, and 26.7% of PRP-T/HBV10 recipients and 70.0%, 46.7%, and 46.7% of PRP-OMPC/HBV15 recipients, respectively. Fever > or = 37.8 degrees C and irritability were reported by 0% and 16.7% of licensed vaccine recipients, 10.3% and 23.3% of PRP-T/HBV10 recipients and 30.0% and 16.7% of PRP-OMPC/HBV15 recipients, respectively. There were no apparent differences between the groups in the proportion of participants achieving predefined, threshold or seroprotective immune responses. Geometric mean antibody levels for all antigens were similar except for anti-PRP levels, which were 19.0 microg/mL in recipients of the licensed vaccine, 40.8 microg/mL in PRP-T/HBV10 recipients and 9.4 microg/mL in PRP-OMPC/HBV15 recipients. We conclude that the hexavalent formulations appear generally well tolerated and immunogenic as a booster dose in these toddlers.

Postlicensure epidemiology of childhood vaccination: the Danish experience

The efficacy, the ability to confer protection against a target disease and the safety of a vaccine are assessed in great detail before licensure. However, inherent limitations in the prelicensure assessment necessitate continued epidemiological evaluations of efficacy and safety issues after the introduction of vaccines into use. In Denmark, the opportunities available for epidemiological research are unique. In 2001, an initiative was undertaken to take advantage of these opportunities to study the postlicensure epidemiology of childhood vaccination with respect to effectiveness and safety. First, we describe the unique opportunities for postlicensure research in Denmark with respect to the data sources available and the epidemiological and statistical methods used. We then describe a number of recent postlicensure studies of effectiveness and safety that took advantage of these opportunities. Specifically, studies on the effectiveness of Haemophilus influenzae type b vaccination, the effectiveness of pertussis vaccination, the impact of a preschool pertussis booster on infant pertussis, measles-mumps-rubella vaccine and autism, thimerosal-containing vaccine and autism, measles-mumps-rubella vaccine and febrile seizures, childhood vaccination and Type 1 diabetes, and childhood vaccination and nontargeted infectious disease are discussed.

Association between birth order and emergency room visits and acute hospital admissions following pediatric vaccination: a self-controlled study

Objective

We investigated the association between a child's birth order and emergency room (ER) visits and hospital admissions following 2-,4-,6- and 12-month pediatric vaccinations.

Methods

We included all children born in Ontario between April 1^st, 2006 and March 31^st, 2009 who received a qualifying vaccination. We identified vaccinations, ER visits and admissions using health administrative data housed at the Institute for Clinical Evaluative Sciences. We used the self-controlled case series design to compare the relative incidence (RI) of events among 1^st-born and later-born children using relative incidence ratios (RIR).

Results

For the 2-month vaccination, the RIR for 1^st-borns versus later-born children was 1.37 (95% CI: 1.19–1.57), which translates to 112 additional events/100,000 vaccinated. For the 4-month vaccination, the RIR for 1^st-borns vs. later-borns was 1.70 (95% CI: 1.45–1.99), representing 157 additional events/100,000 vaccinated. At 6 months, the RIR for 1^st vs. later-borns was 1.27 (95% CI: 1.09–1.48), or 77 excess events/100,000 vaccinated. At the 12-month vaccination, the RIR was 1.11 (95% CI: 1.02–1.21), or 249 excess events/100,000 vaccinated.

Conclusions

Birth order is associated with increased incidence of ER visits and hospitalizations following vaccination in infancy. 1^st-born children had significantly higher relative incidence of events compared to later-born children.

Safety observation study on haemophilus influenza type B conjugate vaccines injected at different sites in Chinese infants

In the present study, the safety of Haemophilus influenza type b conjugate vaccines inoculated in the upper arm deltoid and vastus lateralis muscle was evaluated. 680 infants aged 2-5 months and 6-12 months were selected to be the research subjects in whom the Hib conjugate vaccines were inoculated by injection in the upper arm deltoid and vastus lateralis muscle, respectively. The safety analysis indicated that there were no statistic differences in the incidence rates of adverse reactions when the Hib conjugate vaccines were inoculated at different sites. So we concluded that the safety of inoculation injection of Hib conjugate vaccines in vastus lateralis muscle was the same as that inoculated in the upper arm deltoid.

Adapting group sequential methods to observational postlicensure vaccine safety surveillance: results of a pentavalent combination DTaP-IPV-Hib vaccine safety study

To address gaps in traditional postlicensure vaccine safety surveillance and to promote rapid signal identification, new prospective monitoring systems using large health-care database cohorts have been developed. We newly adapted clinical trial group sequential methods to this observational setting in an original safety study of a combination diphtheria and tetanus toxoids and acellular pertussis adsorbed (DTaP), inactivated poliovirus (IPV), and Haemophilus influenzae type b (Hib) conjugate vaccine (DTaP-IPV-Hib) among children within the Vaccine Safety Datalink population. For each prespecified outcome, we conducted 11 sequential Poisson-based likelihood ratio tests during September 2008-January 2011 to compare DTaP-IPV-Hib vaccinees with historical recipients of other DTaP-containing vaccines. No increased risk was detected among 149,337 DTaP-IPV-Hib vaccinees versus historical comparators for any outcome, including medically attended fever, seizure, meningitis/encephalitis/myelitis, nonanaphylactic serious allergic reaction, anaphylaxis, Guillain-Barré syndrome, or invasive Hib disease. In end-of-study prespecified subgroup analyses, risk of medically attended fever was elevated among 1- to 2-year-olds who received DTaP-IPV-Hib vaccine versus historical comparators (relative risk = 1.83, 95% confidence interval: 1.34, 2.50) but not among infants under 1 year old (relative risk = 0.83, 95% confidence interval: 0.73, 0.94). Findings were similar in analyses with concurrent comparators who received other DTaP-containing vaccines during the study period. Although lack of a controlled experiment presents numerous challenges, implementation of group sequential monitoring methods in observational safety surveillance studies is promising and warrants further investigation.

Long-term immunogenicity assessment of a DTaP-IPV//PRP-T vaccine given at 2, 4, 6 and 18-19 months of age, and immunogenicity and safety of a DTaP-IPV vaccine given as a booster dose at 4 to 6 years of age in Thai children

Booster vaccination of infants aims to further reduce the burden of childhood infectious diseases. This study assessed the antibody persistence induced by a primary series vaccination at 2, 4, 6 months of age and a first booster at 18-19 months of age with a pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b combined vaccine (DTaP-IPV//PRP-T) in 4-6 year-old Thai children (N=123). The safety and immunogenicity of a tetravalent acellular pertussis combined vaccine (containing the same DTaP-IPV antigens as the previous vaccine) given as a second booster at 4 to 6 years of age was also evaluated. Seroprotective antibody levels against diphtheria (> or = 0.01 IU/ml), tetanus (> or = 0.10 IU/ml), and polioviruses (> or = 8 1/dil) were maintained 4-6 years after primary-vaccination and first booster by > or = 92.7% of children, and anti-pertussis antibodies > or = 5 EU/ml were observed in the majority of children. The second booster with DTaP-IPV elicited a strong response for all antigens. GMT or GMC ratios for all antigens at the pre- and post-booster samples were from 4.7 to 52.5. Primary vaccination at 2, 4, 6 and a booster at 18-19 months of age with the DTaP-IPV//PRP-T vaccine induced satisfactory antibody persistence at 4-6 years of age. A second booster with DTaP-IPV induced a strong immune response and was well tolerated.

The safety advantages of pentavalent vaccines

The ever-growing vaccination schedule can cause patients, parents, and nurse practitioners undue concern. Combination vaccines may provide an answer. This integrative review demonstrates that pentavalent vaccines offer adequate immunity, are well tolerated, and safe when compared to vaccines administered separately.

[Adverse events due to the immunization--case report]

INTRODUCTION

An adverse event after immunization is a medical incident following the administration of vaccine, which can be connected with vaccine usage. This event could be a reaction to a vaccine component or lapse in vaccine handling, transport and storage or coincidental event. The assessment of severity of this reaction and the decision about prospective permanent contraindications for futher immunization are to be made by the regional expert team for permanent contraindications. This is regulated by low.

CASE REPORT

A series of adverse events after immunization in three children ofa single family is reported. As regulated by law, all three children were vaccinated with different vaccines, from 2007 to 2010. Although the recorded events were diverse by their nature, way of clinical manifestation and severity they all required hospitalization. In addition to being siblings, the three children had the same atopic diseases in their personal and family anamnesis. All adverse events were explored including allergological/immunological tests. Thanks to the good cooperation of involved general practicioners, pediatricians, members of expert team for permanent contraindications and clinicians, two of three children received the full series of vaccines in optimal time.

DISCUSSION

Decision making about futher immunization of children with adverse event after vaccine administration depends on the nature and severity of developed medical condition, results of medical exploration, existing immunity and personal risk of getting disease and subsequent complications.

CONCLUSION

Bearing in mind the significance of immunization for personal and collective immunity, good cooperation of all physicians and experts involved in each single case of adverse event is required

Risk of febrile seizures and epilepsy after vaccination with diphtheria, tetanus, acellular pertussis, inactivated poliovirus, and Haemophilus influenzae type B

CONTEXT

Vaccination with whole-cell pertussis vaccine carries an increased risk of febrile seizures, but whether this risk applies to the acellular pertussis vaccine is not known. In Denmark, acellular pertussis vaccine has been included in the combined diphtheria-tetanus toxoids-acellular pertussis-inactivated poliovirus-Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine since September 2002.

OBJECTIVE

To estimate the risk of febrile seizures and epilepsy after DTaP-IPV-Hib vaccination given at 3, 5, and 12 months.

DESIGN, SETTING, AND PARTICIPANTS

A population-based cohort study of 378,834 children who were born in Denmark between January 1, 2003, and December 31, 2008, and followed up through December 31, 2009; and a self-controlled case series (SCCS) study based on children with febrile seizures during follow-up of the cohort.

MAIN OUTCOME MEASURES

Hazard ratio (HR) of febrile seizures within 0 to 7 days (0, 1-3, and 4-7 days) after each vaccination and HR of epilepsy after first vaccination in the cohort study. Relative incidence of febrile seizures within 0 to 7 days (0, 1-3, and 4-7 days) after each vaccination in the SCCS study.

RESULTS

A total of 7811 children were diagnosed with febrile seizures before 18 months, of whom 17 were diagnosed within 0 to 7 days after the first (incidence rate, 0.8 per 100,000 person-days), 32 children after the second (1.3 per 100,000 person-days), and 201 children after the third (8.5 per 100,000 person-days) vaccinations. Overall, children did not have higher risks of febrile seizures during the 0 to 7 days after the 3 vaccinations vs a reference cohort of children who were not within 0 to 7 days of vaccination. However, a higher risk of febrile seizures was found on the day of the first (HR, 6.02; 95% CI, 2.86-12.65) and on the day of the second (HR, 3.94; 95% CI, 2.18-7.10), but not on the day of the third vaccination (HR, 1.07; 95% CI, 0.73-1.57) vs the reference cohort. On the day of vaccination, 9 children were diagnosed with febrile seizures after the first (5.5 per 100,000 person-days), 12 children after the second (5.7 per 100,000 person-days), and 27 children after the third (13.1 per 100,000 person-days) vaccinations. The relative incidences from the SCCS study design were similar to the cohort study design. Within 7 years of follow-up, 131 unvaccinated children and 2117 vaccinated children were diagnosed with epilepsy, 813 diagnosed between 3 and 15 months (2.4 per 1000 person-years) and 1304 diagnosed later in life (1.3 per 1000 person-years). After vaccination, children had a lower risk of epilepsy between 3 and 15 months (HR, 0.63; 95% CI, 0.50-0.79) and a similar risk for epilepsy later in life (HR, 1.01; 95% CI, 0.66-1.56) vs unvaccinated children.

CONCLUSIONS

DTaP-IPV-Hib vaccination was associated with an increased risk of febrile seizures on the day of the first 2 vaccinations given at 3 and 5 months, although the absolute risk was small. Vaccination with DTaP-IPV-Hib was not associated with an increased risk of epilepsy.

[Cardiorespiratory events after first immunization in premature infants: a prospective cohort study]

OBJECTIVE

To investigate whether all preterm infants born before 33 weeks of gestation need cardiorespiratory monitoring due to the risk of cardiorespiratory disturbances following their first vaccination at 2 months of age.

DESIGN

A prospective observational cohort study.

METHOD

During a period lasting a little over a year, all preterm infants who were being cared for at the neonatal ward of Medical Centre Alkmaar because they had been born before 33 weeks of gestation received their first immunization at the age of 2 months and were subsequently monitored. Infants who had already been discharged by that time were readmitted for this purpose.

RESULTS

In this cohort of 41 premature infants whose mean gestational age was 30.8 weeks (SD: 1.9), 10 of these had a mild decrease in oxygen saturation or bradycardia; three developed a moderate cardiorespiratory event requiring tactile stimulation. The incidence of disturbances was higher in younger and lower-weight infants and those who had experienced more severe morbidity during the neonatal phase. Moderate disturbances only occurred in the infants who had not yet been discharged from hospital after birth.

CONCLUSION

It is recommended that still-hospitalized premature infants receive their first immunizations under cardiorespiratory monitoring, as events were observed during a period of 0-24 hours thereafter. In premature infants who had already been discharged - mainly because they were less premature or dysmature - immunization without cardiorespiratory monitoring appeared to be safe. Further research is needed for substantiating this strategy.

A phase III randomized, controlled study to assess and compare the immunogenicity and tolerability of single and multi-dose vials of DTwP-Hib, a fully liquid quadravalent vaccine and their comparison with TETRAct-Hib vaccine in Indian infants aged 6-14 weeks

Both WHO and IAP encourage using combination vaccines, wherever feasible. The phase III trial reported here was conducted to assess and compare the immunogenicity, tolerability and safety of two quadravalent vaccines, Quadrovax(®) (new vaccine), and TETRAct-Hib(®) (available in the market) in a multicentre study, in India. In all, 361 infants aged 6-8 weeks were enrolled, out of which 339 completed the study. The vaccination was done at 6-10-14 weeks following EPI/WHO recommended immunization schedule. Blood samples were collected prior to the administration of first dose and one month after the third dose. Postvaccination, geometric mean titres for each component did not differ significantly between the single dose vial and multi dose vial subgroups and among the two study groups. Adverse events observed were within the range quoted in literature. Quadrovax(®) vaccine manufactured by SIIL was found to be safe, immunogenic and non-inferior to the comparator vaccine. The quadravalent vaccine is best recommended in the second year of life when children receive their booster dose at 15-18 months. It can be given to infants during primary immunization series at 6, 10 and 14 weeks of age when Hepatitis B vaccine is given in a separate arm or to infants at 10 weeks who receive the Hepatitis B vaccine separately following the 0, 6 and 14 weeks or 0, 1 and 6 months schedule.

[Immunogenicity and safety of DTaP-IPV//PRP-T combined vaccine in infants in China]

OBJECTIVE

The aim of this study was to demonstrate the immunogenicity and safety of diphtheria, tetanus, pertussis (acellular, component), poliomyelitis (inactivated) vaccine (adsorbed) and Haemophilus influenzae type b conjugate vaccine (DTaP-IPV//PRP-T) combined vaccine compared with commercially available DTaP (diphtheria, tetanus and pertussis), Haemophilus influenzae type b (Hib), tetanus conjugate and IPV monovalent vaccine.

METHODS

Subjects were randomly divided into three groups, Group A and Group B were DTaP-IPV//PRP-T combined vaccine (PENTAXIM(TM)) vaccinated at 2, 3, 4 months of age or 3, 4, 5 months of age respectively; Group C was commercially available DTaP. Hib tetanus conjugate (Act-HIB(TM)) and IPV (IMOVAX PolioTM(TM)) vaccines vaccinated at 3, 4, 5 months of age. All groups received booster dose at 18 to 20 months of age, with antibody titers tested. Non-inferiority analysis was demonstrated in terms of seroprotection/seroconversion rates between Group A, Group B respectively and Group C. Safety information was collected after each vaccination to assess the safety of investigational vaccines.

RESULTS

The non-inferiority of DTaP-IPV//PRP-T combined vaccine vaccinated at 2, 3, 4 or 3, 4, 5 months of age versus DTaP, Hib tetanus conjugate and IPV vaccine was demonstrated for all vaccine antigens in both primary and booster phases in terms of seroprotection/seroconversion rates. DTaP-IPV//PRP-T combined vaccine was well tolerated. The rate of solicited/unsolicited severe adverse reactions was very low and similar to the control vaccines.

CONCLUSION

DTaP-IPV//PRP-T combined vaccine was highly immunogenic with good safety profile in Chinese infants, which was comparable to the commercially available control vaccines.

Immunogenicity and safety of fully liquid DTaP₅-IPV-Hib compared with DTaP₃-IPV/Hib when both coadministered with a heptavalent pneumococcal conjugate vaccine (PCV7) at 2, 3, 4, and 12 to 18 months of age: a phase III, single-blind, randomised, controlled, multicentre study

This study compared immunogenicity and safety of DTaP(5)-IPV-Hib to DTaP(3)-IPV/Hib coadministered with PCV7 at 2, 3, and 4 months (primary series) and a fourth-dose booster at 12-18 months of age. Seroprotection rates for DTaP(5)-IPV-Hib were high (noninferior to DTaP(3)-IPV/Hib for the primary series) for antigens common to both vaccines and PCV7 antigens. Geometric mean concentration (GMC) for Hib antibodies were higher in the DTaP(5)-IPV-Hib group than the DTaP(3)-IPV/Hib group after the primary series and booster dose; GMCs or titers for other antigens were generally similar between groups after the primary series and booster dose. Safety profiles were similar between groups.

[Lack of association between thimerosal-containing vaccines and autism]

In Poland, administered childhood vaccines still contain thimerosal as a preservative. Despite the access to mercury free formulas, the most of children are still vaccinated by thimerosal-containing vaccines (TCV) owing to economical reasons. That circumstances caused the rising discussion on potential harmful influence of TCVs on children health. The objective of this analysis was to determine an association of TCVs exposure with the risk of autism. Study population included 96 cases diagnosed with childhood or atypical autism and 192 controls matched individually by year of birth, gender, and physician's practice. Data on autism diagnose and vaccination history were from GPs. Data on the other possible autism risk factors were collected from mothers. Conditional logistic regression was used to assess the risk of autism due to TCVs exposure. No significant association was found between TCVs exposure and autism. After adjusting to potential confounders, odds ratios of the risk of autism developing for infants vaccinated with TCVs were 1.52 (95% CI: 0.29-11.11) for doses 12.5-87.5 microg, 2.78 (95% CI: 0.29-11.11) for 100-137.5 microg and 1.97 (95% CI: 0.37-18.95) for these exposed > or = 150 microg. Our study revealed no evidence of an association between TCVs and autism.

Safety and reactogenicity of DTPa-HBV-IPV/Hib and DTPa-IPV/I-Hib vaccines in a post-marketing surveillance setting

Combination vaccines have been shown to improve the timeliness of vaccination and vaccine coverage. Safety and reactogenicity of combined diphtheria-tetanus-acellular pertussis-inactivated poliovirus and Haemophilus influenzae type b vaccine (DTPa-IPV/Hib, Infanrix IPV+Hib, GlaxoSmithKline Biologicals) was assessed in two clinical studies. In Study A, 2,590 subjects received DTPa-IPV/Hib at 3, 4 and 5 months of age with a booster at 18 months. In Study B, 702 subjects received the same schedule but with DTPa-hepatitis B-IPV/Hib (DTPa-HBV-IPV/Hib, Infanrix hexa, GlaxoSmithKline Biologicals) vaccine administered at 5 months of age. Reactogenicity was assessed for four days after each dose using diary cards. Serious adverse events (SAEs) were assessed until 24 months of age. The vaccines were well tolerated. After primary vaccination, irritability was the most frequently reported grade 3 general symptom (0.8% of doses in both studies). Fever (axillary) > 39 degrees C was infrequent (0.3% of doses in Study A; 0.5% of doses in Study B). After the booster dose, the most frequently reported grade 3 symptom was redness (5%) in Study A and pain (0.5%) in Study B. An axillary temperature > 39 degrees C was reported in 1.1% of subjects. Throughout the study period, 646 SAEs were reported, of which 6 SAEs were considered to be vaccination-related. The reactogenicity and safety profile of the combined DTPa-IPV/Hib vaccine was good when used for primary and booster vaccinations in over 3,000 Singaporean infants. Substitution of DTPa-IPV/Hib with DTPa-HBV-IPV/Hib at Month 5 reduced the number of injections required at this age by one.

Primary and booster vaccination in Latin American children with a DTPw-HBV/Hib combination: a randomized controlled trial

BACKGROUND

Diphtheria-tetanus-whole-cell pertussis (DTPw)-based combination vaccines are an attractive option to rapidly achieve high coverage and protection against other important pathogens, such as hepatitis B virus (HBV) and Haemophilus influenzae type B (Hib). To ensure adequate antigen supply, GlaxoSmithKline Biologicals has introduced a new DTPw antigen source and developed a new DTPw-HBV/Hib combination vaccine containing a reduced amount of Hib polyribosylribitol phosphate (PRP). This study was undertaken to compare the immunogenicity and reactogenicity of this new DTPw-HBV/Hib vaccine with a licensed DTPw-HBV/Hib vaccine (Tritanrix™-HBV/Hib).

METHODS

This was a randomized, partially-blind, multicenter study in three countries in Latin America (Argentina, Chile and Nicaragua). Healthy children received either the new DTPw-HBV/Hib vaccine (1 of 3 lots; n = 439; double-blind) or Tritanrix™-HBV/Hib (n = 146; single-blind) co-administered with oral poliovirus vaccine (OPV) at 2, 4 and 6 months, with a booster dose at 18-24 months.

RESULTS

One month after the end of the 3-dose primary vaccination course, the new DTPw-HBV/Hib vaccine was non-inferior to Tritanrix™-HBV/Hib in terms of seroprotection/vaccine response rates for all component antigens; ≥97.3% and ≥93.9% of subjects in the two groups, respectively, had seroprotective levels of antibodies against diphtheria, tetanus, hepatitis B and Hib and a vaccine response to the pertussis component. Persistence of antibodies against all vaccine antigens was comparable between groups, with marked increases in all antibody concentrations after booster administration in both groups. Both vaccines were generally well-tolerated as primary and booster doses.

CONCLUSIONS

Results confirm the suitability of this new DTPw-HBV/Hib vaccine comprising antigens from a new source and a reduced PRP content for inclusion into routine childhood vaccination programs.

TRIAL REGISTRATION

http://www.clinicaltrials.gov NCT00332566.

Evaluation of an acellular pertussis, diphtheria, tetanus, inactivated poliovirus, Hib-conjugate combined vaccine (Pentaxim) at 2, 4, and 6 months of age plus hepatitis B vaccine at birth, 2, and 6 months of age in infants in Thailand

The objective of this study was to evaluate the immunogenicity and safety of a pentavalent vaccine (Pentaxim) containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, and Hib polysaccharide-conjugate (DTaP-IPV//PRP-T) antigens, in Thai children. One hundred eighty-six infants who had received a hepatitis B vaccine at birth were given a pentavalent vaccine at 2, 4 and 6 months of age and a hepatitis B vaccine concomitantly at 2 and 6 months of age. Immunogenicity was high for each vaccine antigen. The study vaccine was well tolerated and side effects were few. After the third dose, 100% of subjects had an anti-PRP > or = 0.15 microg/ml and 96.5% > or = 1.0 microg/ml; the anti-PRP GMT was 9.53 microg/ml. Seroprotective rates for diphtheria and tetanus (> or = 0.01 IU/ml) were 99.4% and 100%, respectively, and 100% for all three poliovirus types (> or = 8 1/dil U). The vaccine response rates to pertussis antigens (a 4-fold increase in antibody titer were 94.1% for PT and 93.0% for FHA. The DTaP-IPV//PRP-T vaccine given at 2, 4 and 6 months of age concomitantly with a monovalent hepatitis B vaccine, was well tolerated and highly immunogenic for primary immunization of infants in Thailand.

Reduced rate of side effects associated with separate administration of MMR and DTaP-Hib-IPV vaccinations

BACKGROUND

According to the Israeli immunization schedule, 1 year old babies should receive two concomitant vaccinations: MMR (measles-mumps-rubella), and DTap-Hib-IPV (diphtheria tetanus acellular pertussis-Haemophilus influenzae type b-poliomyelitis). However, about one-third of infants in Israel receive these vaccinations separately. Nurses at a primary care prevention clinic in Israel observed that the separate mode of vaccination is associated with a lower rate of side effects.

OBJECTIVES

To validate this observation and determine whether it represents an exception or the rule.

METHODS

A nested prospective follow-up study was conducted in a primary care clinic in Israel. The survey included 191 mothers and their offspring born during 2004/2005. The mothers were interviewed over the telephone 2 weeks after the day of vaccination.

RESULTS

The rate of adverse effects in children who received the injections separately was significantly lower than among those who were vaccinated simultaneously (40% vs. 57%).

CONCLUSIONS

It may be necessary to reconsider the current vaccination policy regarding concomitant injections.

Immunogenicity and safety of a pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type B conjugate combination vaccine (Pentaxim) with hepatitis B vaccine

OBJECTIVE

To obtain immunogenicity and safety data for a pentavalent combination vaccine (diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Hib polysaccharide-conjugate).

DESIGN

Multicenter, open, Phase III clinical study. A DTaP-IPV//PRP approximately T vaccine (Pentaxim) was given at 6,10,14 weeks of age; and Hepatitis B vaccine at 0,6,14 or at 6,10,14 weeks of age. Immunogenicity assessed 1 month post-3rd dose; safety assessed for 30 minutes by the investigator, then by parents and investigators to 8 days and 30 days post-vaccination.

SETTING

Tertiary-care hospitals.

PARTICIPANTS/PATIENTS

226 healthy Indian infants (6 weeks of age).

MAIN OUTCOME MEASURES

Immunogenicity and safety.

RESULTS

Immunogenicity was high for each vaccine antigen, and similar to a historical control study (France) following a 2,3,4 month of age administration schedule. Post-3rd dose, 98.6% of subjects had anti-PRP >0.15 mg/mL and 90.0% had titers >1.0 mg/mL; the anti-PRP GMT was 4.1 micrograms/mL. Seroprotection rates for diphtheria and tetanus (>0.01 IU/mL) were 99.1% and 100%; and 100%, 99.1% and 100%, for polio types 1,2 and 3 (>8 [1/dil]) respectively. Anti-polio GMTs were 440.5,458.9, and 1510.7 (1/dil) for types 1,2 and 3 respectively. The vaccine response rates to pertussis antigens (4-fold increase in antibody concentration) were 93.7% for PT and 85.7% for FHA; the 2-fold increase was 97.1% and 92.4%. Vaccine reactogenicity was low with adverse reaction incidence not increasing with subsequent doses.

CONCLUSION

The DTaP-IPV//PRP approximately T vaccine, given concomitantly with monovalent hepatitis B vaccine, was highly immunogenic at 6, 10 and 14 weeks of age in infants in India. The vaccine was well tolerated.

Evaluation of the immunogenicity and reactogenicity of a DTPa-HBV-IPV combination vaccine Co-administered with a hib conjugate vaccine either as a single injection of a hexavalent combination or as two separate injections at 3, 5 and 11 months of age

A combined DTPa-HBV-IPV/Hib vaccine containing diphtheria (D), tetanus (T), acellular pertussis (Pa), hepatitis B (HBV) and types 1, 2 and 3 inactivated polioviruses (IPV) extemporaneously mixed with a conjugated Haemophilus influenzae type b (Hib) vaccine (Group 1) was compared to the DTPa-HBV-IPV and Hib vaccines (Group 2) administered separately at 3, 5 and 11 months of age (n = 440). A microneutralization assay was used to detect antibodies against the 3 polio virus types (cut-off 1:8 dil), RIA for anti-HBs antibodies (cut-off 10 mIU/ml) and ELISA for antibodies against all other vaccine antigens (cut-off: 0.1 IU/ml for anti-tetanus and anti-diphtheria antibodies; 5 El.U/ml for antibodies against each of the 3 acellular pertussis antigens and 0.15 microg/ml for anti-PRP antibodies). Similar immune responses were observed in both groups 1 month after dose 2 as well as after dose 3. Six months after dose 2 however, the proportion of subjects maintaining an anti-tetanus antibody concentration > or = 0.1 IU/ml was lower in Group 2 and a slight group difference in favour of Group 1 was also observed for anti-PRP, anti-diphtheria and anti-polio type 1 antibody persistence prior to the third dose. The overall incidence of local and general solicited symptoms was similar in both groups. One subject discontinued study vaccination following an SAE considered to be related to vaccination. The DTPa-HBV-IPV/Hib combined vaccine is immunogenic and well tolerated when administered according to a 3, 5 and 11 month vaccination schedule and can therefore be considered as a feasible alternative to the separate administration of the pentavalent DTPa-HBV-IPV and the monovalent Hib vaccines.