A randomised controlled trial with a diphtheria-tetanus-acellular pertussis (dTpa) vaccine in adults

The aim of this assessor-blinded trial was to compare the immunogenicity and reactogenicity of a candidate diphtheria, tetanus toxoids and acellular pertussis vaccine with reduced antigen content for diphtheria and pertussis (dTpa) with a licensed reduced adult-type diphtheria-tetanus vaccine Td (reduced diphtheria content) and with an experimental candidate monovalent acellular pertussis vaccine with reduced antigen content (pa). The dTpa and pa vaccines had identical pertussis antigen content. A total of 299 healthy adults (> or =18 years, mean age: 30.1 years+/-10.7) were randomised into 3 groups to receive a single dose of one of the study vaccines. In all groups, clinically significant reactions (severe) were infrequent (0-6%) and no serious adverse events were reported during the study. The incidence of local and systemic reactions following the administration of dTpa was comparable to the Td vaccine group. Of the total study group, prior to vaccination 52. 3 and 93.2% of the subjects had anti-diphtheria and anti-tetanus antibody levels > or = 0.1 IU/ml, respectively; and 73.1, 98.2 and 74.5% of the subjects were seropositive for pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) antibodies, respectively. One month after vaccination, a similar percentage of subjects in the dTpa and Td groups had anti-diphtheria (88.4% vs 90. 1%) and anti-tetanus (100% vs 98.9%) antibody levels > or =0.1 IU/ml. Similar anti-FHA (100%) and anti-PRN (98.9%) vaccine response rates were seen in the dTpa and pa groups, while the anti-PT vaccine response rates were 96.8 and 100.0%, respectively. The dTpa vaccine is as well tolerated and immunogenic as the licensed Td vaccine, and additionally, can also boost antibodies against pertussis.     

Immunogenicity and safety of one dose of diphtheria,tetanus, acellular pertussis and poliomyelitis vaccine (Repevax) followed by two doses of diphtheria,tetanus and poliomyelitis vaccine (Revaxis) in adults aged ≥40 years not receiving a diphtheria- and tetanus-containing vaccination in the last 20 years

Introduction

The immunogenicity and safety of one dose of Tdap-IPV (tetanus, diphtheria, acellular pertussis and inactivated poliomyelitis vaccine) and two doses of Td-IPV (tetanus, diphtheria and inactivated poliomyelitis vaccine) were assessed in adults who had not received a diphtheria- and tetanus-containing vaccine in the last 20 years.

Methods

This open-label, multicentre study was conducted in adults aged ≥40 years with no diphtheria- and tetanus-containing vaccine in the last 20 years. Participants received one dose of Tdap-IPV followed by two doses of Td-IPV (0, 1, 6 month schedule). Primary immunogenicity objectives: to demonstrate acceptable seroprotection rates (percentage of participants with antibody titre above threshold) post-dose 3 for diphtheria (≥0.1 IU/mL by seroneutralization assay [SNA]); tetanus (≥0.1 IU/mL by enzyme-linked immunosorbent assay [ELISA]); and poliomyelitis (≥8 1/dil by SNA); and to evaluate the percentage of participants with an antibody concentration ≥5 EU/mL (by ELISA) for pertussis antigens post-dose 1. Seroprotection rates were acceptable if the lower limit of the 95% confidence interval (CI) was >95%. Percentage of participants with basic clinical immunity against diphtheria (≥0.01 IU/mL) was also assessed. Safety (adverse events [AEs] and serious AEs) was assessed after each dose.

Results

Overall, 336 participants were included (mean age: 60.2 years). Post-dose 3 seroprotection rates were: diphtheria, 94.6% (CI 91.5–96.8); tetanus and poliomyelitis, 100% (CI: 98.8–100). Percentage of participants with an antibody titre ≥5 EU/mL against pertussis antigens was ≥95.8% for all five pertussis components. Basic clinical immunity against diphtheria was achieved in 100% (CI: 98.8–100) of participants. AEs were reported more frequently following vaccination with Tdap-IPV (post-dose 1: 65.3%) than with Td-IPV (post-dose 2: 48.3%; post-dose 3: 50.3%).

Conclusions

This study highlights the benefits of using Tdap-IPV followed by two doses of Td-IPV in an adult population to achieve maximal protection against diphtheria, tetanus, poliomyelitis and pertussis simultaneously.     

Booster vaccination of toddlers with reduced antigen content diphtheria–tetanus–acellular pertussis vaccine

Immunogenicity and reactogenicity of DTPa and reduced antigen dTpa booster vaccines were compared to a hepatitis A control vaccine in DTPa-primed toddlers aged 18–20 months. Post-booster, all DTPa and dTpa recipients were seroprotected against diphtheria and tetanus, and ≥93.3% had a booster response to pertussis. There were similar reactogenicity rates in the DTPa and dTpa vaccine recipients. Few Grade 3 symptoms were reported. Just over one in four children in the control group had diphtheria antibody at or potentially below the correlate of protection benchmark (0.016 IU/ml). Larger studies should evaluate potential benefits of reduced antigen vaccines and seroprotection in children who do not receive a booster dose of DTPa at this age, including protection against diphtheria until subsequent booster doses are given.     

Immunogenicity and safety of a booster dose of diphtheria,tetanus, acellular pertussis and inactivated poliomyelitis vaccine (Tdap-IPV; Repevax) administered concomitantly versus non-concomitantly with an influenza vaccine (Vaxigrip) to adults aged ≥60 years: An open-label,randomised trial

Background

Annual influenza vaccination provides an opportunity to administer a booster dose of diphtheria, tetanus, acellular pertussis and inactivated poliomyelitis vaccine (Tdap-IPV) to the elderly. This study evaluated immune responses to and safety of the two vaccines administered concomitantly or sequentially to elderly individuals in France and Germany.

Methods

Individuals aged ≥60 years who had received a diphtheria/tetanus booster within 5–15 years were randomised (1:1) to receive either Tdap-IPV and an inactivated influenza vaccine concomitantly (Group 1) or inactivated influenza vaccine then Tdap-IPV 28–35 days later (Group 2). Antibody titres were measured before and 28–35 days after each vaccination.

Results

The mean age of randomised individuals (n = 954) was 68.8 years. Post-vaccination seroprotection rates (≥0.1 IU/mL for diphtheria/tetanus and ≥8 1/dilution for polio) for Group 1 were non-inferior to Group 2 for diphtheria (85.4% vs. 87.5%), tetanus (both 100%), polio type 1 (99.8% vs. 100%), polio type 2 (both 100%) and polio type 3 (99.3% vs. 99.8%). Similarly, percentages of individuals with pertussis antibodies ≥5 EU/mL for Group 1 were non-inferior to Group 2: pertussis toxin (94.3% vs. 98.1%), filamentous haemagglutinin (99.8% vs. 100%), pertactin (97.3% vs. 96.0%), fimbriae 2 and 3 (91.7% vs. 89.5%). Post-vaccination geometric mean titres of anti-influenza haemagglutinin antibodies for Group 1 were non-inferior to Group 2. Adverse events following administration of Tdap-IPV were similar in both study groups, with no vaccine-related serious adverse events.

Conclusion

Tdap-IPV and inactivated influenza vaccine can be administered concomitantly in the elderly without impairing tolerability or the immune response to either vaccine.     

Immunogenicity of a combined diphtheria-tetanus-acellular pertussis vaccine in adults

Two clinical studies were undertaken to evaluate the immunogenicity of an adult-type dTpa booster vaccine (Boostrix by GlaxoSmithKline Biologicals). Blood samples taken prior to vaccination showed that 24.4 and 13.0% of subjects were seronegative for diphtheria and tetanus antibodies, respectively. Moreover, about one-third of the vaccinees had no detectable levels of antibodies to pertussis toxoid (PT) or pertactin (PRN). One month post-vaccination, more than 93% of all individuals, regardless of age or type of vaccine received, had seroprotective antibody levels for diphtheria and tetanus (> or = 0.1IU/ml). In those individuals vaccinated with the adult-type dTpa vaccine (Boostrix), more than 98% were found to be seropositive for antibodies to all three pertussis antigens (PT, filamentous haemogluttin (FHA), and PRN). These data suggest that immunity to diphtheria, tetanus and pertussis (DTP) in adults wanes and that booster vaccination with an adult-type combined dTpa vaccine would boost the serological response to diphtheria antitoxin, tetanus antitoxin and antibodies to Bordetella pertussis PT, FHA and PRN.     

Immunogenicity of the reduced-antigen-content dTpa vaccine (Boostrix(®)) in adults 55 years of age and over: a sub-analysis of four trials

Background

Older adults, especially those over 65 years, are at risk of more severe morbidity from diphtheria, tetanus and pertussis and may transmit pertussis to unvaccinated or not yet fully vaccinated infants, but data on their response to reduced-antigen-content tetanus, diphtheria and acellular pertussis (dTpa) vaccines are lacking.

Methods

A sub-analysis pooled immunogenicity results in 293 adults aged 55+ years (mean age 64.4 years) from four randomised, controlled clinical trials of dTpa vaccine (Boostrix^®, GlaxoSmithKline Biologicals) with or without IPV co-administration, or dTpa-IPV (Boostrix^® IPV).

Results

Seroprotective antibody levels were achieved by 82.8% for diphtheria and 94.5% for tetanus. For pertussis antigens, the booster response rate, defined as initially seronegative subjects [<5 EU/mL] reaching ≥5 EU/mL; or a ≥2-fold increase in antibody concentration if initially seropositive was 89.2% for pertussis toxoid, 95.8% for filamentous haemagglutinin and 94.5% for pertactin. Post-booster geometric mean concentrations (GMC) increased for all antigens. Post-booster anti-tetanus and anti-PRN GMCs tended to be higher in 55- to 64-year olds than in those aged 65+.

Conclusion

Larger numbers of subjects over 75 years are needed to better define responses in advanced age, but these data suggest that a single booster dose of dTpa or dTpa-IPV induces good immunological responses in most, and that these vaccines could be readily integrated into existing programmes.     

A decennial booster dose of reduced antigen content diphtheria, tetanus, acellular pertussis vaccine (Boostrix™) is immunogenic and well tolerated in adults

Reduced-antigen-content diphtheria-tetanus-acellular-pertussis (dTpa) vaccines are predominantly recommended for once-in-a-lifetime use. A second dTpa (Boostrix™, GlaxoSmithKline Biologicals) administration in 164 adults previously vaccinated with dTpa 10 years previously was evaluated. Before the decennial booster, 89.4% and 94.8% subjects were seroprotected (antibodies ≥0.1 IU/mL) for diphtheria and tetanus, respectively. One-month post-booster, all subjects were seroprotected/seropositive against all vaccine antigens. Robust GMC increases indicated a booster response similar to the first booster. The decennial booster was well tolerated without serious adverse events, consistent with product experience. This study supports replacing traditional Td boosters with dTpa, and use of Boostrix™ as a decennial booster.This study is registered at www.clinicaltrials.comNCT00548171.     

Immunogenicity and safety of a tetanus toxoid,reduced diphtheria toxoid and three-component acellular pertussis vaccine in adults 19–64 years of age

Purpose

This study was conducted to assess the immunogenicity and safety of a tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine containing three pertussis antigens (Boostrix^®, Tdap3v), currently licensed in the US for use in adolescents 10–18 years of age, in adults 19–64 years of age.

Methods

2284 healthy adults, aged 19–64 years, were randomized to receive a single dose of Tdap vaccine, either Tdap3v or a five-pertussis component Tdap vaccine (Adacel^®, Tdap5v) licensed for adult use in the US. Blood samples were taken before and 1 month after vaccination. Reactogenicity was assessed for 15 days after vaccination.

Results

Tdap3v was comparable to Tdap5v in eliciting seroprotective levels of antibodies to diphtheria and tetanus toxoids, with >98% of subjects having post-vaccination seroprotective antibody levels (≥0.1 IU/mL) against diphtheria or tetanus toxoids. The pertussis components of Tdap3v were shown to be immunogenic in adults, with booster responses to pertussis toxoid (PT), filamentous hemagglutinin (FHA), and pertactin (PRN) observed in 77.2%, 96.9%, and 93.2%, respectively, of Tdap3v recipients, and in 47.1%, 94.0%, and 91.7%, respectively, of Tdap5v recipients. Anti-pertussis antibody GMCs in Tdap3v recipients exceeded those observed in infants following primary DTaP vaccination, in whom efficacy against pertussis disease was subsequently demonstrated. Injection site reactions (pain, redness, and swelling) and fever ≥37.5 °C (99.5 °F) were reported significantly more often (p < 0.05) by Tdap5v recipients than by Tdap3v recipients. Fatigue preventing normal daily activities was reported by a small but significantly greater percentage of Tdap3v recipients (2.5%) than Tdap5v recipients (1.2%, p < 0.05).

Conclusion

In adult recipients, Tdap3v was comparable to an approved Tdap vaccine in providing seroprotection against diphtheria and tetanus, and produced immune responses to pertussis antigens consistent with protection against disease. The overall safety profile of Tdap3v was generally comparable to that of Tdap5v [NCT #106316].     

Tolerability and antibody response in adolescents and adults revaccinated with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine adsorbed (Tdap) 4-5 years after a previous dose

Background

Although decennial adult boosters of tetanus and diphtheria toxoids are recommended in Canada and the United States, a second dose of pertussis vaccine is not currently recommended for adults.

Methods

This open-label, postmarketing, multicenter study evaluated the tolerability and immunogenicity of a second dose of an adult formulation of tetanus, diphtheria, and pertussis vaccine (Tdap) in adolescents and adults 5 years after a first dose.

Results

A total of 545 participants from previous Tdap vaccine studies, ranging in age from 15 to 69 years, participated in this study. Of these participants, 94.2% had at least one solicited adverse event after the booster dose such as injection-site erythema (28.6%), swelling (25.6%), or pain (87.6%) or a systemic adverse event such as myalgia (61.0%), headache (53.2%), malaise (38.2%), or fever (6.5%). These adverse events were slightly more frequent than after the initial dose. Postvaccination, 100% of participants had a tetanus antibody level ≥0.10 IU/mL and 95% had a diphtheria antibody level ≥0.10 IU/mL. For pertussis, 82.1% (pertussis toxoid), 96.7% (filamentous hemagglutinin), 95.6% (pertactin), and 99.8% (fimbriae) had a postvaccination antibody threshold of ≥50 EU/mL.

Conclusion

A second dose of Tdap vaccine 5 years after the initial dose was well tolerated and immunogenic in adolescents and adults.     

Anti-pertussis antibody kinetics following DTaP-IPV booster vaccination in Norwegian children 7–8 years of age

At the age of 7–8 years a booster of diphtheria, tetanus, acellular pertussis and polio vaccine is recommended for children in Norway. In this cross-sectional study we have analysed the antibody levels against pertussis vaccine antigens in sera from 498 children aged 6–12 years. The purposes of this study were to investigate the duration of the booster response against the pertussis vaccine antigens pertussis toxin (PT) and filamentous haemagglutinin (FHA); to determine the presence of high levels of pertussis antibodies in absence of recent vaccination; and to analyse how booster immunisation may interfere with the serological pertussis diagnostics. Prior to the booster the IgG antibody levels against PT revealed a geometric mean of 7.3 IU/ml. After the booster the geometric mean peak anti-PT IgG response reached to 45.6 IU/ml, followed by a steady decline in antibody levels over the next few years. The IgG anti-FHA levels followed the anti-PT IgG profiles. Three years after the booster the geometric mean IgG levels were only slightly above pre-booster levels. Prior to the booster 44% of the sera contained ≤5 IU/ml of anti-PT IgG compared to18% 3 years after and 30% 4 years after the booster. When recently vaccinated children were excluded, 6.2% of the children had anti-PT IgG levels above 50 IU/ml which may indicate pertussis infection within the last 2 years. This study indicates that the currently used acellular pertussis vaccines induce moderate immune responses to the pertussis antigens and that the antibodies wane within few years after the booster. This lack of sustained immune response may partly be responsible for the increased number of pertussis cases observed in this age group during the last years.     

Immunogenicity and safety of a combined diphtheria, tetanus, acellular pertussis, and inactivated poliovirus vaccine (DTaP-IPV) compared to separate administration of standalone DTaP and IPV vaccines: a randomized, controlled study in infants in the Republic of Korea

This randomized trial enrolled 442 infants in the Republic of Korea to assess the immunogenicity and safety of a combined diphtheria, tetanus, acellular pertussis, and inactivated poliovirus vaccine (DTaP-IPV; Tetraxim™) for primary vaccination at 2, 4 and 6 months of age compared with DTaP and IPV vaccines given separately. Immunogenicity was high in both groups; seroprotection and seroconversion rates of the combined vaccine (Group A) were non-inferior to the control vaccines (Group B). All subjects were seroprotected against poliovirus types 1, 2 and 3 (≥8 1/dil) and anti-diphtheria (≥0.01 IU/mL); 99.0% were seroprotected against tetanus (≥0.1 IU/mL). At least 93.6% had anti-diphtheria antibody titers ≥0.1 IU/mL. Anti-pertussis toxoid (PT) and anti-filamentous haemagglutinin (FHA) seroconversion (≥4-fold increase in antibody titer) rates were 96.6% and 94.4% for Group A, 92.2% and 78.4% for Group B. Most solicited reactions occurred within 4 days of vaccination, resolved within 3 days and were mild. Severe solicited reactions occurred after ≤0.5% of doses in Group A and ≤0.9% in Group B. No withdrawals occurred because of adverse events. The DTaP-IPV combined vaccine given at 2, 4, and 6 months of age was well tolerated; immunogenicity was similar to the control vaccines.     

Antitoxins for diphtheria and tetanus decline more slowly after vaccination with DTwP than with DTaP: A study in a Chinese population

Objectives

DTP vaccines are used for the prevention of pertussis, diphtheria and tetanus. In 2007, in Gaobeidian city, China, the DTwP vaccine was replaced with DTaP. This study described the diphtheria and tetanus sero-epidemiology in subjects vaccinated solely with DTwP or DTaP.

Methods

Blood samples were obtained between October 2012 and June 2013 from 587 healthy subjects aged 2–17 years. Serum IgG antibodies against diphtheria and tetanus were determined using ELISA. Interrupted time series analyses examined the changes in antitoxin levels over time and analyzed the alterations in diphtheria and tetanus antitoxin levels after the vaccine switch.

Results

Mean concentrations of diphtheria antitoxin and tetanus antitoxin were 0.074 IU/ml (95% CI 0.065–0.084) and 0.063 IU/ml (95% CI 0.053–0.076). The protection rates (antitoxins >0.01 IU/ml) for diphtheria and tetanus were 88.25% and 82.11%. Mean antitoxin levels for both diphtheria and tetanus decreased with increasing age, but this decrease was much slower for DTwP than DTaP.

Conclusions

Although the observed protection rates for diphtheria and tetanus were sufficient to prevent an outbreak at present, the means levels of diphtheria and tetanus antitoxins decreased with increasing age; therefore, booster vaccinations at 7 and 12 years of age would be strengthened in Gaobeidian city, China.     

High levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria-tetanus-acellular pertussis vaccine

There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N=310, Td+pa group N=77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.     

Immunity to tetanus and diphtheria in the UK in 2009

Introduction

This study aimed to estimate the immunity of the UK population to tetanus and diphtheria, including the potential impact of new glycoconjugatate vaccines, and the addition of diphtheria to the school leaver booster in 1994.

Methods

Residual sera (n = 2697) collected in England in 2009/10 were selected from 18 age groups and tested for tetanus and diphtheria antibody. Results were standardised by testing a panel of sera (n = 150) to enable comparison with a previously (1996) published serosurvey. Data were then standardised to the UK population.

Results

In 2009, 83% of the UK population were protected (≥0.1 IU/mL) against tetanus compared to 76% in 1996 (p = 0.079), and 75% had at least basic protection against diphtheria (≥0.01 IU/mL) in 2009 compared to 60% in 1996 (p < 0.001). Higher antibody levels were observed in those aged 1–3 years in 2009 compared to 1996 for both tetanus and diphtheria. Higher diphtheria immunity was observed in those aged 16–34 years in 2009 compared to 1996 (geometric mean concentration [GMC] 0.15 IU/mL vs. 0.03 IU/mL, p < 0.001). Age groups with the largest proportion of susceptible individuals to both tetanus and diphtheria in 2009 were <1 year old (>29% susceptible), 45–69 years (>20% susceptible) and 70+ years (>32% susceptible). Low immunity was observed in those aged 10–11 years (>19% susceptible), between the scheduled preschool and school leaver booster administration.

Discussion

The current schedule appears to induce protective levels; increases in the proportions protected/GMCs were observed for the ages receiving vaccinations according to UK policy. Glycoconjugate vaccines appear to have increased immunity, in particular for diphtheria, in preschool age groups. Diphtheria immunity in teenagers and young adults has increased as a result of the addition of diphtheria to the school leaver booster. However, currently older adults remain susceptible, without any further opportunities for immunisations planned according to the present schedule.     

High levels of antibody in adults three years after vaccination with a reduced antigen content diphtheria-tetanus-acellular pertussis vaccine

There is increasing interest in prevention of pertussis in adults by vaccination, but little is known about the duration of the antibody response to pertussis, diphtheria or tetanus in reduced antigen content vaccines formulated for adult use. Follow-up of a clinical trial including 550 adults comparing responses to reduced antigen content diphtheria-tetanus-acellular pertussis (dTpa) vaccine, or a licensed Td vaccine, provided the opportunity to evaluate this. Blood samples were collected at 0, 1, 12, 24 and 36 months following vaccination; of the original cohort of 550, 387 subjects (dTpa group N = 310, Td + pa group N = 77) were tested at month 36. Following a decrease in antibody levels against all vaccine antigens between one and 24 months following vaccination, levels stabilized during the third year, remaining higher at 36 months than pre-vaccination for all vaccine antigens. In particular, more than 90% of subjects remained seropositive for pertussis toxin and pertactin antibodies at 36 months after vaccination, suggesting ongoing protection against pertussis. Adult-formulated dTpa vaccines could replace Td for routine booster vaccination of older individuals.     

Immunogenicity and reactogenicity of co-administered tetanus-diphtheria-acellular pertussis (Tdap) and tetravalent meningococcal conjugate (MCV4) vaccines compared to their separate administration

In the United States, co-administration of tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccine and tetravalent meningococcal conjugate vaccine (MCV4) is recommended in adolescents. In this clinical study, 1341 adolescents received Tdap (Boostrix® GlaxoSmithKline) and MCV4 (Menactra®, Sanofi-Pasteur) simultaneously or sequentially one month apart. Co-administration of Tdap + MCV4 was well tolerated and immunogenic, resulting in high levels of antibodies against diphtheria, tetanus, pertussis and meningococcal serogroup A,C,W-135 and Y antigens. The data provide support for current recommendations for co-administration of Tdap and MCV4 vaccines at the same office visit.     

Immunogenicity of a low-dose diphtheria,tetanus and acellular pertussis combination vaccine with either inactivated or oral polio vaccine compared to standard-dose diphtheria,tetanus, acellular pertussis when used as a pre-school booster in UK children: A 5-year follow-up of a randomised controlled study

This serological follow up study assessed the kinetics of antibody response in children who previously participated in a single centre, open-label, randomised controlled trial of low-dose compared to standard-dose diphtheria booster preschool vaccinations in the United Kingdom (UK). Children had previously been randomised to receive one of three combination vaccines: either a combined adsorbed tetanus, low-dose diphtheria, 5-component acellular pertussis and inactivated polio vaccine (IPV) (Tdap–IPV, Repevax^®; Sanofi Pasteur MSD); a combined adsorbed tetanus, low-dose diphtheria and 5-component acellular pertussis vaccine (Tdap, Covaxis^®; Sanofi Pasteur MSD) given concomitantly with oral polio vaccine (OPV); or a combined adsorbed standard-dose diphtheria, tetanus, 2-component acellular pertussis and IPV (DTap–IPV, Tetravac^®; Sanofi Pasteur MSD). Blood samples for the follow-up study were taken at 1, 3 and 5 years after participation in the original trial (median, 5.07 years of age at year 1), and antibody persistence to each vaccine antigen measured against defined serological thresholds of protection.All participants had evidence of immunity to diphtheria with antitoxin concentrations greater than 0.01 IU/mL five years after booster vaccination and 75%, 67% and 79% of children who received Tdap–IPV, Tdap + OPV and DTap–IPV, respectively, had protective antitoxin levels greater than 0.1 IU/mL. Long lasting protective immune responses to tetanus and polio antigens were also observed in all groups, though polio responses were lower in the sera of those who received OPV.Low-dose diphtheria vaccines provided comparable protection to the standard-dose vaccine and are suitable for use for pre-school booster vaccination.     

Recurrence of extensive injection site reactions following DTPa or dTpa vaccine in children 4-6 years old

Objectives

The aim of this study was to compare the immunogenicity and reactogenicity of a lower dose diphtheria, tetanus and pertussis vaccine (dTpa) with the recommended vaccine (DTPa) given as a fifth dose to 4-6-year old children who previously experienced an extensive injection site reaction (ISR).

Material and methods

Children aged 4-6 years who had experienced an extensive ISR following a 4th dose of DTPa were recruited and randomly assigned to receive either the recommended DTPa or the lower dose dTpa vaccine. Parents recorded local reactions and systemic events for 15 days following vaccination. Immunogenicity was assessed pre and post vaccination by ELISA for diphtheria (D), tetanus (T), pertussis toxin (PT), filamentous haemagglutinin (FHA), and pertactin (PRN).

Results

A total of 53 participants were vaccinated. There was a 72% recurrence rate of ISR, with a trend (p = 0.055) towards fewer ISR in the dTpa (61.5%) compared with the DTPa group (85.2%). There was no difference in reports of pain or irritability between groups. All participants had seroprotective levels of antibody to D and T and seroresponse to each of the 3 pertussis antigens following vaccination with higher GMCs in DTPa vs dTpa group. There was no increase in antibody avidity observed post vaccination, regardless of vaccine given.

Conclusion

Recurrence of ISR with the 5th dose of diphtheria, tetanus and pertussis vaccination in children who have previously experienced an extensive ISR is high. Vaccination with a dTpa vaccine may reduce the risk of fifth dose ISR.     

Immunogenicity and reactogenicity of a decennial booster dose of a combined reduced-antigen-content diphtheria–tetanus–acellular pertussis and inactivated poliovirus booster vaccine (dTpa–IPV) in healthy adults

BackgroundPertussis in adults and adolescents could be reduced by replacing traditional tetanus and diphtheria (Td) boosters with reduced-antigen-content diphtheria–tetanus–acellular pertussis (dTpa) vaccines. This study evaluated the administration of dTpa–IPV (dTpa–inactivated poliovirus) in adults ten years after they received a booster dose of either dTpa–IPV, dTpa+IPV or Td–IPV in trial NCT01277705.MethodsOpen multicentre, phase IV study (www.clinicaltrials.gov NCT01323959) in which healthy adults, who had received a previous dose of dTpa–IPV, dTpa+IPV or Td–IPV ten years earlier, received a single decennial booster dose of dTpa–IPV (Boostrix™-polio, GlaxoSmithKline Vaccines). Blood samples were collected before and one month after booster vaccination. Antibody concentrations against all vaccine antigens were measured and reactogenicity and safety were assessed.ResultsA total of 211 subjects (mean age 50.3 years) received vaccination of whom 201 were included in the according-to-protocol cohort for immunogenicity. Before the decennial dTpa–IPV booster, ≥71.0% subjects were seroprotected/seropositive against all vaccine antigens. One month after the booster dose, all subjects were seroprotected against tetanus and poliovirus types 2 and 3; ≥95.7% subjects were seroprotected against diphtheria and ≥98.3% against poliovirus type 1. Anti-pertussis booster responses for the various antigens were observed in ≥76.5% (pertussis toxoid; PT), ≥85.1% (filamentous haemagglutinin; FHA) and ≥63.2% (pertactin; PRN) of subjects. During the 4-day follow-up, the overall incidence of local AEs was 71.6%, 75.0% and 72.2% in dTpa–IPV, dTpa+IPV and Td–IPV groups, respectively. Pain was the most frequent solicited local adverse event (AE; ≥62.7% subjects) and fatigue the most frequent solicited general AE (≥18.5%). No serious AEs were reported during the study.ConclusionA booster dose of dTpa–IPV was immunogenic and well tolerated in adults who had received a booster dose of either dTpa–IPV, dTpa+IPV or Td–IPV, ten years previously and supports the repeated administration of dTpa–IPV.     

Immunogenicity and safety of diphtheria–tetanus vaccine in pre-adolescent and adolescent South Koreans

This study was conducted to compare the immunogenicity and safety of diphtheria–tetanus (Td) vaccine between pre-adolescents aged 11–12 years and adolescents aged 13–18 years. A total of 277 subjects (132 pre-adolescents and 145 adolescents) participated. After vaccination, all subjects (100%) in both groups exhibited seroprotective antibody levels (≥0.1 IU/mL) against diphtheria or tetanus toxoids. Although local adverse events following vaccination were more frequently observed in the pre-adolescent group than in the adolescent group (p = 0.006), these events resolved within 7 days. Our study shows Td vaccination at age 11–12 years to be immunogenic and tolerable.