Clinical Pharmacology for Boostrix
Mechanism Of Action
Active Immunization
Tetanus is a condition manifested primarily by neuromuscular dysfunction caused by a potent exotoxin released by C. tetani. Protection against disease is due to the development of neutralizing antibodies to the tetanus toxin. A serum tetanus antitoxin level of at least 0.01 IU/mL, measured by neutralization assays, is considered the minimum protective level.2 A level ≥0.1 IU/mL by ELISA has been considered as protective.
Diphtheria is an acute toxin-mediated infectious disease caused by toxigenic strains of C. diphtheriae. Protection against disease is due to the development of neutralizing antibodies to the diphtheria toxin. A serum diphtheria antitoxin level of 0.01 IU/mL, measured by neutralization assays, is the lowest level giving some degree of protection; a level of 0.1 IU/mL by ELISA is regarded as protective. Diphtheria antitoxin levels ≥1.0 IU/mL by ELISA have been associated with long-term protection.3
Pertussis (whooping cough) is a disease of the respiratory tract caused by B. pertussis. The role of the different components produced by B. pertussis in either the pathogenesis of, or the immunity to, pertussis is not well understood.
Passive Immunization To Prevent Pertussis In Infants
Antibodies to pertussis antigens from individuals vaccinated during the third trimester of pregnancy are transferred transplacentally to prevent pertussis in infants younger than 2 months of age.
Clinical Studies
Effectiveness Of BOOSTRIX, INFANRIX, And PEDIARIX
Effectiveness Of BOOSTRIX
The effectiveness of the tetanus and diphtheria toxoid components of BOOSTRIX is based on the immunogenicity of the individual antigens compared with U.S.-licensed vaccines using established serologic correlates of protection. The effectiveness of the pertussis components of BOOSTRIX was evaluated by comparison of the immune response of adolescents and adults following an initial dose of BOOSTRIX to the immune response of infants following a 3-dose primary series of INFANRIX or by comparison of the immune response of adults following an additional dose of BOOSTRIX to the immune response of infants following a 3-dose primary series of PEDIARIX. In addition, the ability of BOOSTRIX to induce a booster response to each of the antigens was evaluated.
Efficacy Of INFANRIX Against Pertussis
The efficacy of a 3-dose primary series of INFANRIX in infants has been assessed in 2 clinical studies: A prospective efficacy trial conducted in Germany employing a household contact study design and a double-blind, randomized, active Diphtheria nd Tetanus Toxoids (DT)-controlled trial conducted in Italy sponsored by the National Institutes of Health (NIH) (for details see INFANRIX prescribing information). In the household contact study, the protective efficacy of INFANRIX in infants against WHO-defined pertussis (21 days or more of paroxysmal cough with infection confirmed by culture and/or serologic testing) was calculated to be 89% (95% CI: 77%, 95%). When the definition of pertussis was expanded to include clinically milder disease, with infection confirmed by culture and/or serologic testing, the efficacy of INFANRIX against ≥7 days of any cough was 67% (95% CI: 52%, 78%) and against ≥7 days of paroxysmal cough was 81% (95% CI: 68%, 89%) (for details see INFANRIX prescribing information).
Immune Responses To Pertussis Antigens Of PEDIARIX Compared With INFANRIX
The diphtheria, tetanus, and pertussis components in PEDIARIX are the same as those in INFANRIX. The effectiveness of the pertussis component of PEDIARIX was determined in clinical trials by comparison to antibody responses to INFANRIX (for details see PEDIARIX prescribing information).
Immune Responses To Pertussis Antigens Of BOOSTRIX Compared With INFANRIX Or PEDIARIX
Although a serologic correlate of protection for pertussis has not been established, serological data from a subset of infants immunized with a 3-dose primary series of INFANRIX in the German household contact study were compared with the sera of adolescents and adults immunized with an initial dose of BOOSTRIX [see Clinical Studies]. Serological data from infants immunized with a 3-dose primary series of PEDIARIX in an additional pediatric study were compared with the sera of adults immunized with an additional dose of BOOSTRIX [see Clinical Studies]. The GMCs to each of the pertussis antigens 1 month following a dose of BOOSTRIX were compared with the GMCs of infants following INFANRIX administered at 3, 4, and 5 months of age or were compared with the GMCs of infants following PEDIARIX administered at 2, 4, and 6 months of age. The majority of subjects in the study of INFANRIX had only anti-PT serology data.
Immunological Evaluation following An Initial Dose Of BOOSTRIX
Adolescents (Aged 10 To 18 Years)
In a multicenter, randomized, observer-blinded, controlled study conducted in the United States (NCT00109330), the immune responses to each of the antigens contained in BOOSTRIX were evaluated in sera obtained approximately 1 month after administration of a single dose of vaccine to adolescent subjects (aged 10 to 18 years). Of the subjects enrolled in this study, approximately 76% were aged 10 to 14 years and 24% were aged 15 to 18 years. Approximately 98% of participants in this study had received the recommended series of 4 or 5 doses of either DTwP or a combination of DTwP and DTaP in childhood. The racial/ethnic demographics were as follows: White 85.8%, Black 5.7%, Hispanic 5.6%, Oriental 0.8%, and other 2.1%.
Response to Tetanus and Diphtheria Toxoids
The antibody responses to the tetanus and diphtheria toxoids of BOOSTRIX compared with Td vaccine are shown in Table 9. One month after a single dose, anti-tetanus and anti-diphtheria seroprotective rates (≥0.1 IU/mL by ELISA) and booster response rates were comparable between BOOSTRIX and the comparator Td vaccine.
Table 9. Antibody Responses to Tetanus and Diphtheria Toxoids following BOOSTRIX Compared with Td Vaccine in Adolescents Aged 10 to 18 Years (ATP Cohort for Immunogenicity)
| Antibodies |
n |
% ≥0.1 IU/mLa
(95% CI) |
% ≥1.0 IU/mLa
(95% CI) |
% Booster Responseb
(95% CI) |
| Anti-tetanus |
| BOOSTRIX |
2,469-2,516 |
|
|
|
| Pre-vaccination |
|
97.7
(97.1, 98.3) |
36.8
(34.9, 38.7) |
– |
| Post-vaccination |
|
100
(99.8, 100)c |
99.5
(99.1, 99.7)d |
89.7
(88.4, 90.8)c |
| Td |
817-834 |
|
|
|
| Pre-vaccination |
|
96.8
(95.4, 97.9) |
39.9
(36.5, 43.4) |
– |
| Post-vaccination |
|
100
(99.6, 100) |
99.8
(99.1, 100) |
92.5
(90.5, 94.2) |
| Anti-diphtheria |
| BOOSTRIX |
2,463-2,515 |
|
|
|
| Pre-vaccination |
|
85.8
(84.3, 87.1) |
17.1
(15.6, 18.6) |
– |
| Post-vaccination |
|
99.9
(99.7, 100)c |
97.3
(96.6, 97.9)d |
90.6
(89.4, 91.7)c |
| Td |
814-834 |
|
|
|
| Pre-vaccination |
|
84.8
(82.1, 87.2) |
19.5
(16.9, 22.4) |
– |
| Post-vaccination |
|
99.9
(99.3, 100) |
99.3
(98.4, 99.7) |
95.9
(94.4, 97.2) |
Td = Tetanus and Diphtheria Toxoids, Adsorbed manufactured by MassBiologics.
ATP = According-to-protocol; CI = Confidence Interval.
a Measured by ELISA.
b Booster response: In subjects with pre-vaccination <0.1 IU/mL, post-vaccination concentration ≥0.4 IU/mL. In subjects with pre-vaccination concentration ≥0.1 IU/mL, an increase of at least 4 times the pre-vaccination concentration.
c Seroprotection rate or booster response rate to BOOSTRIX was non-inferior to Td (upper limit of 2-sided 95% CI on the difference for Td minus BOOSTRIX ≤10%).
d Non-inferiority criteria not prospectively defined for this endpoint. |
Response to Pertussis Antigens
The booster response rates of adolescents to the pertussis antigens are shown in Table 10. For each of the pertussis antigens the lower limit of the 2-sided 95% CI for the percentage of subjects with a booster response exceeded the pre-defined lower limit of 80% for demonstration of an acceptable booster response.
Table 10. Booster Responses to the Pertussis Antigens following BOOSTRIX in Adolescents Aged 10 to 18 Years (ATP Cohort for Immunogenicity)
| Pertussis Antibodies |
n |
BOOSTRIX
% Booster Responsea (95% CI) |
| Anti-PT |
2,677 |
84.5 (83.0, 85.9) |
| Anti-FHA |
2,744 |
95.1 (94.2, 95.9) |
| Anti-PRN |
2,752 |
95.4 (94.5, 96.1) |
ATP = According-to-protocol; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
a Booster response: In initially seronegative subjects (<5 EL.U./mL), post-vaccination antibody concentrations ≥20 EL.U./mL. In initially seropositive subjects with pre-vaccination antibody concentrations ≥5 EL.U./mL and <20 EL.U./mL, an increase of at least 4 times the pre-vaccination antibody concentration. In initially seropositive subjects with pre-vaccination antibody concentrations ≥20 EL.U./mL, an increase of at least 2 times the pre-vaccination antibody concentration. |
The GMCs to each of the pertussis antigens 1 month following a single dose of BOOSTRIX were compared with the GMCs of a subset of infants following a 3-dose primary series of INFANRIX in the German household contact study [see Clinical Studies]. Table 11 presents the results for the total immunogenicity cohort in both studies (vaccinated subjects with serology data available for at least 1 pertussis antigen). Anti-PT, anti-FHA, and anti-PRN antibody concentrations observed in adolescents 1 month after a single dose of BOOSTRIX were non-inferior to those infants following a primary vaccination series with INFANRIX.
Table 11. Ratio of GMCs to Pertussis Antigens following 1 Dose of BOOSTRIX in Adolescents Aged 10 to 18 Years Compared with 3 Doses of INFANRIX in Infants (Total Immunogenicity Cohort)
| Pertussis Antibodies |
BOOSTRIX |
INFANRIX |
GMC Ratio:
BOOSTRIX/INFANRIX |
| (n) |
(n) |
(95% CI) |
| Anti-PT |
2,941 |
2,884 |
1.90 (1.82, 1.99)a |
| Anti-FHA |
2,979 |
685 |
7.35 (6.85, 7.89)a |
| Anti-PRN |
2,978 |
631 |
4.19 (3.73, 4.71)a |
GMC = Geometric mean antibody concentration, measured in ELISA units; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects for GMC evaluation.
a GMC following BOOSTRIX was non-inferior to GMC following INFANRIX (lower limit of 95% CI for the GMC ratio of BOOSTRIX/INFANRIX >0.67). |
Adults (Aged 19 To 64 Years)
A multicenter, randomized, observer-blinded study, conducted in the United States (NCT00346073), evaluated the immunogenicity of BOOSTRIX compared with the licensed comparator Tdap vaccine (Sanofi Pasteur). Vaccines were administered as a single dose to subjects (N = 2,284) who had not received a tetanus-diphtheria booster within 5 years. The immune responses to each of the antigens contained in BOOSTRIX were evaluated in sera obtained approximately 1 month after administration. Approximately 33% of subjects were aged 19 to 29 years, 33% were aged 30 to 49 years, and 34% were aged 50 to 64 years. Among subjects in the combined vaccine groups, 62% were female; 84% of subjects were White, 8% Black, 1% Asian, and 7% were of other racial/ethnic groups.
Response to Tetanus and Diphtheria Toxoids
The antibody responses to the tetanus and diphtheria toxoids of BOOSTRIX compared with the comparator Tdap vaccine are shown in Table 12. One month after a single dose, anti-tetanus and anti-diphtheria seroprotective rates (≥0.1 IU/mL by ELISA) were comparable between BOOSTRIX and the comparator Tdap vaccine.
Table 12. Antibody Responses to Tetanus and Diphtheria Toxoids following 1 Dose of BOOSTRIX Compared with the Comparator Tdap Vaccine in Adults Aged 19 to 64 Years (ATP Cohort for Immunogenicity)
| Antibodies |
n |
% ≥0.1 IU/mLa |
% ≥1.0 IU/mLa |
| (95% CI) |
(95% CI) |
| Anti-tetanus |
| BOOSTRIX |
1,445-1,447 |
|
|
| Pre-vaccination |
|
95.9 (94.8, 96.9) |
71.9 (69.5, 74.2) |
| Post-vaccination |
|
99.6 (99.1, 99.8)b |
98.3 (97.5, 98.9)b |
| Tdap |
727-728 |
|
|
| Pre-vaccination |
|
97.2 (95.8, 98.3) |
74.7 (71.4, 77.8) |
| Post-vaccination |
|
100 (95.5, 100) |
99.3 (98.4, 99.8) |
| Anti-diphtheria |
| BOOSTRIX |
1,440-1,444 |
|
|
| Pre-vaccination |
|
85.2 (83.3, 87.0) |
23.7 (21.5, 26.0) |
| Post-vaccination |
|
98.2 (97.4, 98.8)b |
87.9 (86.1, 89.5)c |
| Tdap |
720-727 |
|
|
| Pre-vaccination |
|
89.2 (86.7, 91.3) |
26.5 (23.3, 29.9) |
| Post-vaccination |
|
98.6 (97.5, 99.3) |
92.0 (89.8, 93.9) |
Tdap = Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Adsorbed manufactured by Sanofi Pasteur.
ATP = According-to-protocol; CI = Confidence Interval.
a Measured by ELISA.
b Seroprotection rates for BOOSTRIX were non-inferior to the comparator Tdap vaccine (lower limit of 95% CI on the difference of BOOSTRIX minus Tdap ≥-10%).
c Non-inferiority criteria not prospectively defined for this endpoint. |
Response to Pertussis Antigens
Booster response rates to the pertussis antigens are shown in Table 13. For the FHA and PRN antigens, the lower limit of the 95% CI for the booster responses exceeded the pre-defined limit of 80% demonstrating an acceptable booster response following BOOSTRIX. The PT antigen booster response lower limit of the 95% CI (74.9%) did not exceed the pre-defined limit of 80%.
Table 13. Booster Responses to the Pertussis Antigens following 1 Dose of BOOSTRIX in Adults Aged 19 to 64 Years (ATP Cohort for Immunogenicity)
| Pertussis Antibodies |
n |
BOOSTRIX
% Booster Responsea
(95% CI) |
| Anti-PT |
1,419 |
77.2 (74.9, 79.3)b |
| Anti-FHA |
1,433 |
96.9 (95.8, 97.7)c |
| Anti-PRN |
1,441 |
93.2 (91.8, 94.4)c |
ATP = According-to-protocol; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
a Booster response: In initially seronegative subjects (<5 EL.U./mL), post-vaccination antibody concentrations ≥20 EL.U./mL. In initially seropositive subjects with pre-vaccination antibody concentrations ≥5 EL.U./mL and <20 EL.U./mL, an increase of at least 4 times the pre-vaccination antibody concentration. In initially seropositive subjects with pre-vaccination antibody concentrations ≥20 EL.U./mL, an increase of at least 2 times the pre-vaccination antibody concentration.
b The PT antigen booster response lower limit of the 95% CI did not exceed the pre-defined limit of 80%.
c The FHA and PRN antigens booster response lower limit of the 95% CI exceeded the pre-defined limit of 80%. |
The GMCs to each of the pertussis antigens 1 month following a single dose of BOOSTRIX were compared with the GMCs of a subset of infants following a 3-dose primary series of INFANRIX in the German household contact study [see Clinical Studies]. Table 14 presents the results for the total immunogenicity cohort in both studies (vaccinated subjects with serology data available for at least 1 pertussis antigen). Anti-PT, anti-FHA, and anti-PRN antibody concentrations observed in adults 1 month after a single dose of BOOSTRIX were non-inferior to those infants following a primary vaccination series with INFANRIX.
Table 14. Ratio of GMCs to Pertussis Antigens following 1 Dose of BOOSTRIX in Adults Aged 19 to 64 Years Compared with 3 Doses of INFANRIX in Infants (Total Immunogenicity Cohort)
| Pertussis Antibodies |
BOOSTRIX |
INFANRIX |
GMC Ratio:
BOOSTRIX/INFANRIX |
| (n) |
(n) |
(95% CI) |
| Anti-PT |
1,460 |
2,884 |
1.39 (1.32, 1.47)a |
| Anti-FHA |
1,472 |
685 |
7.46 (6.86, 8.12)a |
| Anti-PRN |
1,473 |
631 |
3.56 (3.10, 4.08)a |
GMC = Geometric mean antibody concentration; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects for GMC evaluation.
a BOOSTRIX was non-inferior to INFANRIX (lower limit of 95% CI for the GMC ratio of BOOSTRIX/INFANRIX ≥0.67). |
Elderly (Aged 65 Years And Older)
The U.S. elderly (aged 65 years and older) study, a randomized, observer-blinded study (NCT00835237), evaluated the immunogenicity of BOOSTRIX (n = 887) compared with a U.S.-licensed comparator Td vaccine (n = 445) (Sanofi Pasteur). Vaccines were administered as a single dose to subjects who had not received a tetanus-diphtheria booster within 5 years. Among all vaccine recipients, the mean age was approximately 72 years; 54% were female and 95% were White. The immune responses to each of the antigens contained in BOOSTRIX were evaluated in sera obtained approximately 1 month after administration.
Response to Tetanus and Diphtheria Toxoids
Immune responses to tetanus and diphtheria toxoids were measured 1 month after administration of a single dose of BOOSTRIX or a comparator Td vaccine. Anti-tetanus and anti-diphtheria seroprotective rates (≥0.1 IU/mL) were comparable between BOOSTRIX and the comparator Td vaccine (Table 15).
Table 15. Immune Responses to Tetanus and Diphtheria Toxoids following BOOSTRIX or Comparator Td Vaccine in the Elderly Aged 65 Years and Older (ATP Cohort for Immunogenicity)
| Anti-Tetanus and Anti-Diphtheria Titers |
BOOSTRIX |
Td |
| (n = 844-864) |
(n = 430-439) |
| Anti-tetanus |
| % ≥0.1 IU/mL (95% CI) |
96.8 (95.4, 97.8)a |
97.5 (95.6, 98.7) |
| % ≥1.0 IU/mL (95% CI) |
88.8 (86.5, 90.8)a |
90.0 (86.8, 92.6) |
| Anti-diphtheria |
| % ≥0.1 IU/mL (95% CI) |
84.9 (82.3, 87.2)a |
86.6 (83.0, 89.6) |
| % ≥1.0 IU/mL (95% CI) |
52.0 (48.6, 55.4)b |
51.2 (46.3, 56.0) |
Td = Tetanus and Diphtheria Toxoids Adsorbed, a U.S.-licensed Td vaccine, manufactured by Sanofi Pasteur.
ATP = According-to-protocol; CI = Confidence Interval.
a Seroprotection rates for BOOSTRIX were non-inferior to the comparator Td vaccine (lower limit of 95% CI on the difference of BOOSTRIX minus Td ≥-10%).
b Non-inferiority criteria not prospectively defined for this endpoint. |
Response to Pertussis Antigens
The GMCs to each of the pertussis antigens 1 month following a single dose of BOOSTRIX were compared with the GMCs of a subset of infants following a 3-dose primary series of INFANRIX in the German household contact study [see Clinical Studies]. Table 16 presents the results for the total immunogenicity cohort in both studies (vaccinated subjects with serology data available for at least 1 pertussis antigen). Anti-PT, anti-FHA, and anti-PRN antibody concentrations in the elderly 1 month after a single dose of BOOSTRIX were non-inferior to those of infants following a primary vaccination series with INFANRIX.
Table 16. Ratio of GMCs to Pertussis Antigens following 1 Dose of BOOSTRIX in the Elderly Aged 65 Years and Older Compared with 3 Doses of INFANRIX in Infants (Total Immunogenicity Cohort)
| Pertussis Antibodies |
BOOSTRIX |
INFANRIX |
GMC Ratio:
BOOSTRIX/INFANRIX |
| (n) |
(n) |
(95% CI) |
| Anti-PT |
865 |
2,884 |
1.07 (1.00, 1.15)a |
| Anti-FHA |
847 |
685 |
8.24 (7.45, 9.12)a |
| Anti-PRN |
878 |
631 |
0.93 (0.79, 1.10)a |
GMC = Geometric mean antibody concentration; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects for GMC evaluation.
a BOOSTRIX was non-inferior to INFANRIX (lower limit of 95% CI for the GMC ratio of BOOSTRIX/INFANRIX ≥0.67). |
Study In Pregnant Women
The effectiveness of BOOSTRIX immunization during the third trimester of pregnancy to prevent pertussis among infants younger than 2 months of age was based on a re-analysis within a Bayesian meta-analysis framework of the BOOSTRIX-relevant data from an observational case-control study of Tdap vaccine effectiveness.4 In this re-analysis, a conditional logistic regression model controlling for age, maternal education, and family size was fit to data from 108 cases (including 4 cases whose mothers received BOOSTRIX during the third trimester) and 183 controls (including 18 whose mothers received BOOSTRIX during the third trimester) matched by age group (<2 weeks old, ≥2 weeks old) and birth hospital. This yielded a preliminary vaccine effectiveness estimate of 78.0% (95% CI: -38.0, 96.5) for vaccination during the third trimester of pregnancy. This preliminary effectiveness estimate was updated using a Bayesian meta-analysis with an informative prior constructed from four observational studies that provided estimates of the vaccine effectiveness of the non-U.S. formulation of BOOSTRIX against pertussis in infants whose mothers were immunized during pregnancy.5, 6, 7, 8 To account for potential publication bias, this informative prior was downweighted by combining it with an uninformative prior. When the informative prior has 20% weight, the Bayesian update resulted in estimates of effectiveness of vaccination during the third trimester of pregnancy of 81.5% (95% credible interval:12.9, 94.5). When the informative prior has 90% weight, the Bayesian update resulted in estimates of effectiveness of vaccination during the third trimester of pregnancy of 83.4% (95% credible interval: 55.7, 92.5). The vaccine effectiveness point estimates were consistent, regardless of the weight applied to the informative prior.
Immune Responses To Vaccination In Infants Born To Mothers Who Received BOOSTRIX During Pregnancy
Data are not available on immune responses to US licensed vaccines administered on the US schedule among infants born to mothers who received BOOSTRIX during pregnancy.
In infants whose mothers received BOOSTRIX (non-US formulation) during the third trimester of pregnancy, antibody responses to a non-US licensed DTaP-containing vaccine were diminished for anti-PT, anti-FHA and anti-PRN following the primary series (NCT 02422264), and for anti-PT and anti-FHA following a booster dose (NCT 02853929) compared to infants who received the same vaccine but whose mothers received placebo during pregnancy. Whether the diminished immune responses observed in vaccinated infants whose mothers received BOOSTRIX (non-US formulation) during pregnancy result in diminished effectiveness of pertussis vaccination in infants is unknown.
Immunological Evaluation Following Revaccination With BOOSTRIX
Adults (Aged 20 To 29 Years)
A multicenter, open-label, controlled study conducted in the United States evaluated the immunogenicity of BOOSTRIX in adults aged 20 to 29 years who received an initial dose of BOOSTRIX (n = 128) or the comparator Td vaccine (MassBiologics) (n = 37) in the U.S. adolescent (aged 10 to 18 years) study (NCT01738477). BOOSTRIX was administered to all subjects 10 years after initial vaccination. The immune responses to each of the antigens contained in BOOSTRIX were evaluated in sera obtained approximately 1 month after vaccine administration. Among all vaccine recipients, the mean age was 23.5 years; 45.5% were female, and 87.9% were White.
Response to Tetanus and Diphtheria Toxoids
The antibody responses to the tetanus and diphtheria toxoids of BOOSTRIX are shown in Table 17. One month after vaccination, anti-tetanus and anti-diphtheria seroprotective rates (≥0.1 IU/mL by ELISA) were comparable between groups.
Table 17. Antibody Responses to Tetanus and Diphtheria Toxoids following BOOSTRIX in Adults Aged 20 to 29 Years (ATP Cohort for Immunogenicity)
| Antibodies |
n |
% ≥0.1 IU/mLa
(95% CI) |
% ≥1.0 IU/mLa
(95% CI) |
| Anti-tetanus |
|
|
|
| BOOSTRIXb |
115 |
|
|
| Pre-vaccination |
|
100 (96.8, 100) |
74.8 (65.8, 82.4) |
| Post-vaccination |
|
100 (96.8, 100)c |
100 (96.8, 100)d |
| Tde |
35 |
|
|
| Pre-vaccination |
|
100 (90, 100) |
77.1 (59.9, 89.6) |
| Post-vaccination |
|
100 (90, 100) |
100 (90, 100) |
| Anti-diphtheria |
|
|
|
| BOOSTRIXb |
115 |
|
|
| Pre-vaccination |
|
100 (96.8, 100) |
60.9 (51.3, 69.8) |
| Post-vaccination |
|
100 (96.8, 100)c |
100 (96.8, 100)d |
| Tde |
35 |
|
|
| Pre-vaccination |
|
100 (90, 100) |
65.7 (47.8, 80.9) |
| Post-vaccination |
|
100 (90,100) |
97.1 (85.1, 99.9) |
Td manufactured by MassBiologics.
ATP = According-to-protocol; CI = Confidence Interval.
n = Number of subjects with available results.
a Measured by ELISA.
b Subjects who were revaccinated with BOOSTRIX 10 years after initial vaccination with BOOSTRIX.
c Seroprotection rates following revaccination with BOOSTRIX were non-inferior to an initial dose of BOOSTRIX (Td group) (lower limit of 2-sided 95% CI on the difference for second dose of BOOSTRIX minus first dose of BOOSTRIX ≥-10%).
d Non-inferiority criteria not prospectively defined for this endpoint.
e Subjects who received a dose of BOOSTRIX 10 years after initial vaccination with Td vaccine. |
Response to Pertussis Antigens
The GMCs to each of the pertussis antigens 1 month following revaccination with BOOSTRIX in subjects who had received an initial dose of BOOSTRIX 10 years earlier were compared with the GMCs of infants following a 3-dose primary series of PEDIARIX [see Clinical Studies]. Table 18 presents the results for the ATP cohort for immunogenicity in both studies. Anti-PT, anti-FHA, and anti-PRN antibody concentrations observed in adults 1 month after revaccination with BOOSTRIX were non-inferior to those of infants following a primary vaccination series with PEDIARIX.
Table 18. Ratio of GMCs to Pertussis Antigens following BOOSTRIX in Adults Aged 20 to 29 Years Compared with 3 Doses of PEDIARIX in Infants (ATP Cohort for Immunogenicity)
| Pertussis Antibodies |
BOOSTRIXa
(n) |
PEDIARIX
(n) |
GMC Ratio:
BOOSTRIX/PEDIARIX
(95% CI) |
| Anti-PT |
115 |
149 |
1.81 (1.48, 2.21)b |
| Anti-FHA |
115 |
149 |
2.37 (1.98, 2.83)b |
| Anti-PRN |
115 |
149 |
9.87 (7.80, 12.49)b |
GMC = Geometric mean antibody concentration; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects for GMC evaluation.
a Subjects who were revaccinated with BOOSTRIX 10 years after initial vaccination with BOOSTRIX.
b BOOSTRIX was non-inferior to PEDIARIX (lower limit of 95% CI for the GMC ratio of BOOSTRIX/PEDIARIX ≥0.67). |
Adults (Aged 28 To 73 Years)
A multicenter, open-label, controlled study conducted in the United States evaluated the immunogenicity of BOOSTRIX in adults aged 28 to 73 years who received an initial dose of BOOSTRIX (n = 309) or the licensed comparator Tdap vaccine (Sanofi Pasteur) (n = 138) in the U.S. adult (aged 19 to 64 years) study (NCT00489970). BOOSTRIX was administered to all subjects 9 years after initial vaccination. A control group of newly enrolled adult subjects received an initial dose of BOOSTRIX (n = 362). The immune responses to each of the antigens contained in BOOSTRIX were evaluated in sera obtained approximately 1 month after vaccine administration. Of the subjects enrolled in this study, the mean age was 52.1 years; 62.6% were female, and 86.6% were White.
Response to Tetanus and Diphtheria Toxoids
The antibody responses to the tetanus and diphtheria toxoids of BOOSTRIX are shown in Table 19. One month after vaccination, anti-tetanus and anti-diphtheria seroprotective rates (≥0.1 IU/mL by ELISA) were comparable between groups.
Table 19. Antibody Responses to Tetanus and Diphtheria Toxoids following BOOSTRIX in Adults Aged 28 to 73 Years (ATP Cohort for Immunogenicity)
| Antibodies |
n |
% ≥0.1 IU/mLa
(95% CI) |
% ≥1.0 IU/mLa
(95% CI) |
% Booster Responseb
(95% CI) |
| Anti-tetanus |
| BOOSTRIXc |
268-271 |
|
|
|
| Pre-vaccination |
|
98.1
(95.7, 99.4) |
78.7
(73.3, 83.5) |
|
| Post-vaccination |
|
100
(98.6, 100)d |
99.3
(97.4, 99.9)e |
47.0
(40.9, 53.2)f |
| Tdapg |
120-121 |
|
|
|
| Pre-vaccination |
|
100
(97.0, 100) |
84.2
(76.4, 90.2) |
|
| Post-vaccination |
|
100
(97.0, 100)d |
100
(97.0, 100)e |
36.7
(28.1, 45.9)f |
| Controlh |
324-327 |
|
|
|
| Pre-vaccination |
|
93.8
(90.6, 96.2) |
71.3
(66.0, 76.2) |
|
| Post-vaccination |
|
99.7
(98.3, 100) |
97.6
(95.2, 98.9) |
48.5
(42.9, 54.0) |
| Anti-diphtheria |
|
|
|
|
| BOOSTRIXc |
269-271 |
|
|
|
| Pre-vaccination |
|
91.1
(87.0, 94.2) |
42.4
(36.4, 48.5) |
|
| Post-vaccination |
|
99.3
(97.4, 99.9)d |
91.9
(88.0, 94.8)e |
62.8
(56.7, 68.6)f |
| Tdapg |
118-121 |
|
|
|
| Pre-vaccination |
|
95.8
(90.4, 98.6) |
45.8
(36.6, 55.2) |
|
| Post-vaccination |
|
99.2
(95.5, 100)d |
93.4
(87.4, 97.1)e |
60.2
(50.7, 69.1)f |
| Controlh |
324-326 |
|
|
|
| Pre-vaccination |
|
81.8
(77.1, 85.8) |
28.4
(23.5, 33.6) |
|
| Post-vaccination |
|
97.9
(95.6, 99.1) |
86.5
(82.3, 90.0) |
68.7
(63.4, 73.7) |
Tdap = Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Adsorbed manufactured by Sanofi Pasteur.
ATP = According-to-protocol; CI = Confidence Interval.
n = Number of subjects with available results.
a Measured by ELISA.
b Booster response: In subjects with pre-vaccination <0.1 IU/mL, post-vaccination concentration ≥0.4 IU/mL. In subjects with pre-vaccination concentration ≥0.1 IU/mL, an increase of at least 4 times the pre-vaccination concentration.
c Subjects who were revaccinated with BOOSTRIX 9 years after initial vaccination with BOOSTRIX.
d Seroprotection rates following a dose of BOOSTRIX in subjects who had received an initial dose of BOOSTRIX or the licensed comparator Tdap vaccine were non-inferior to an initial dose of BOOSTRIX (Control Group) (lower limit of 97.5% CI on the difference of BOOSTRIX minus Control Group ≥-10%).
e Non-inferiority criteria not prospectively defined for this endpoint.
f The booster response rates following a dose of BOOSTRIX in subjects who had received an initial dose of BOOSTRIX or the licensed comparator Tdap vaccine did not meet the pre-defined non-inferiority criteria (lower limit of the 97.5% CIs ≥-10% [BOOSTRIX minus Control Group] and [Tdap minus Control Group]).
g Subjects who received a dose of BOOSTRIX 9 years after initial vaccination with Tdap vaccine.
h Control Group = Newly enrolled subjects who received an initial dose of BOOSTRIX. |
Response to Pertussis Antigens
The GMCs to each of the pertussis antigens 1 month following a dose of BOOSTRIX in subjects who had received an initial dose of BOOSTRIX or the licensed comparator Tdap vaccine (Sanofi Pasteur) 9 years earlier were compared with the GMCs of infants following a 3-dose primary series of PEDIARIX [see Clinical Studies]. Table 20 presents the results for the ATP cohort for immunogenicity in both studies. Anti-PT, anti-FHA, and anti-PRN antibody concentrations observed in adults 1 month after a dose of BOOSTRIX were non-inferior to those of infants following a primary vaccination series with PEDIARIX.
Table 20. Ratio of GMCs to Pertussis Antigens following BOOSTRIX in Adults Aged 28 to 73 Years Compared with 3 Doses of PEDIARIX in Infants (ATP Cohort for Immunogenicity)
| Pertussis Antibodies |
Vaccinated with BOOSTRIX 9 Years after Initial Vaccination with: |
PEDIARIX (n) |
GMC Ratio: |
BOOSTRIX
(n) |
Tdap
(n) |
|
BOOSTRIX/ PEDIARIX
(97.5% CI) |
Tdap/ PEDIARIX
(97.5% CI) |
| Anti-PT |
271 |
121 |
149 |
1.33
(1.09, 1.61)a |
1.46
(1.14, 1.87)a |
| Anti-FHA |
271 |
121 |
149 |
2.02
(1.72, 2.37)a |
2.07
(1.68, 2.57)a |
| Anti-PRN |
271 |
121 |
149 |
8.64
(6.85, 10.89)a |
10.90
(8.27, 14.38)a |
Tdap = Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Adsorbed manufactured by Sanofi Pasteur.
GMC = Geometric mean antibody concentration; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects for GMC evaluation.
a BOOSTRIX was non-inferior to PEDIARIX (lower limit of 97.5% CI for the GMC ratio of BOOSTRIX/PEDIARIX ≥0.67). |
Compared with the Control Group, non-inferiority of booster response rates to the pertussis antigens following a dose of BOOSTRIX in subjects who had received an initial dose of BOOSTRIX or another licensed Tdap vaccine (Sanofi Pasteur) was achieved for the PT antigen [BOOSTRIX minus Control Group] and the FHA antigen [Tdap minus Control Group], respectively (Table 21). Non-inferiority was not achieved for FHA and PRN booster response rates [BOOSTRIX minus Control Group] or for PT and PRN booster response rates [Tdap minus Control Group].
Table 21. Booster Responses to the Pertussis Antigens following BOOSTRIX in Adults Aged 28 to 73 Years (ATP Cohort for Immunogenicity)
| Pertussis Antibodies |
n |
% Booster Responsea
(95% CI) |
Difference in Booster Response Rates |
BOOSTRIX minus Control Group
(97.5 % CI) |
Tdap minus Control Group
(97.5% CI) |
| Anti-PT |
| BOOSTRIXb |
271 |
86.7
(82.1, 90.5) |
-2.85
(-9.09, 3.08)c |
|
| Tdapd |
120 |
88.3
(81.2, 93.5) |
|
-1.24
(-10.03, 5.57) |
| Controle |
326 |
89.6
(85.7, 92.7) |
|
|
| Anti-FHA |
| BOOSTRIXb |
271 |
85.6
(80.9, 89.6) |
-7.05
(-13.16, -1.40) |
|
| Tdapd |
120 |
96.7
(91.7, 99.1) |
|
4.01
(-2.38, 8.66)c |
| Controle |
327 |
92.7
(89.3, 95.2) |
|
|
| Anti-PRN |
| BOOSTRIXb |
271 |
77.5
(72.0, 82.3) |
-10.32
(-17.50, -3.38) |
|
| Tdapd |
118 |
83.1
(75.0, 89.3) |
|
-4.76
(-14.53, 3.18) |
| Controle |
320 |
87.8
(83.7, 91.2) |
|
|
Tdap = Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine, Adsorbed manufactured by Sanofi Pasteur.
ATP = According-to-protocol; CI = Confidence Interval; PT = Pertussis toxin; FHA = Filamentous hemagglutinin; PRN = Pertactin.
n = Number of subjects with available results.
a Booster response: In initially seronegative subjects (pre-vaccination antibody concentration below the assay cut-off), post-vaccination antibody concentrations ≥4 times the assay cut-off. In initially seropositive subjects with pre-vaccination antibody concentrations <4 times the assay cut-off, an increase of at least 4 times the pre-vaccination antibody concentration. In initially seropositive subjects with pre-vaccination antibody concentrations ≥4 times the assay cut-off, an increase of at least 2 times the pre-vaccination antibody concentration. Assay cut-offs: anti-PT = 2.693 IU/mL; anti-FHA = 2.046 IU/mL; anti-PRN = 2.187 IU/mL.
b Subjects who were revaccinated with BOOSTRIX 9 years after initial vaccination with BOOSTRIX.
c Non-inferiority of the booster response rate for each pertussis antigen was demonstrated if the lower limit of the 97.5% CI [BOOSTRIX minus Control Group] or [Tdap minus Control Group] was above the pre-defined limit of -10%.
d Subjects who received a dose of BOOSTRIX 9 years after initial vaccination with Tdap vaccine.
e Control Group = Newly enrolled subjects who received an initial dose of BOOSTRIX. |
Concomitant Administration With Meningococcal Conjugate Vaccine
The concomitant use of BOOSTRIX and a tetravalent meningococcal (groups A, C, Y, and W-135) conjugate vaccine (Sanofi Pasteur) was evaluated in a randomized study in healthy adolescents aged 11 to 18 years (NCT00282295). A total of 1,341 adolescents were vaccinated with BOOSTRIX. Of these, 446 subjects received BOOSTRIX administered concomitantly with meningococcal conjugate vaccine at different injection sites, 446 subjects received BOOSTRIX followed by meningococcal conjugate vaccine 1 month later, and 449 subjects received meningococcal conjugate vaccine followed by BOOSTRIX 1 month later.
Immune responses to diphtheria and tetanus toxoids (% of subjects with anti-tetanus and anti-diphtheria antibodies ≥1.0 IU/mL by ELISA), pertussis antigens (booster responses and GMCs), and meningococcal antigens (vaccine responses) were measured 1 month (range: 30 to 48 days) after concomitant or separate administration of BOOSTRIX and meningococcal conjugate vaccine. For BOOSTRIX given concomitantly with meningococcal conjugate vaccine compared with BOOSTRIX administered first, non-inferiority was demonstrated for all antigens, with the exception of the anti-PRN GMC. The lower limit of the 95% CI for the GMC ratio was 0.54 for anti-PRN (pre-specified limit ≥0.67). For the anti-PRN booster response, non-inferiority was demonstrated. It is not known if the efficacy of BOOSTRIX is affected by the reduced response to PRN.
There was no evidence that BOOSTRIX interfered with the antibody responses to the meningococcal antigens when measured by rabbit serum bactericidal assays (rSBA) when given concomitantly or sequentially (meningococcal conjugate vaccine followed by BOOSTRIX or BOOSTRIX followed by meningococcal conjugate vaccine).
Concomitant Administration With FLUARIX (Inactivated Influenza Vaccine)
The concomitant use of BOOSTRIX and FLUARIX was evaluated in a multicenter, open-label, randomized, controlled study (NCT00385255) of 1,497 adults aged 19 to 64 years. In one group, subjects received BOOSTRIX and FLUARIX concurrently (n = 748). The other group received
FLUARIX at the first visit, then 1 month later received BOOSTRIX (n = 749). Sera was obtained prior to and 1 month following concomitant or separate administration of BOOSTRIX and/or FLUARIX, as well as 1 month after the separate administration of FLUARIX.
Immune responses following concurrent administration of BOOSTRIX and FLUARIX were non-inferior to separate administration for diphtheria (seroprotection defined as ≥0.1 IU/mL), tetanus (seroprotection defined as ≥0.1 IU/mL and based on concentrations ≥1.0 IU/mL), PT antigen (anti-PT GMC), and influenza antigens (percent of subjects with hemagglutination-inhibition [HI] antibody titer ≥1:40 and ≥4-fold rise in HI titer). Non-inferiority criteria were not met for the anti-pertussis antigens FHA and PRN. The lower limit of the 95% CI of the GMC ratio was 0.64 for anti-FHA and 0.60 for anti-PRN and the pre-specified limit was ≥0.67. It is not known if the efficacy of BOOSTRIX is affected by the reduced response to FHA and PRN.
Concomitant Administration With SHINGRIX (Zoster Vaccine Recombinant, Adjuvanted)
The concomitant use of BOOSTRIX and SHINGRIX was evaluated in an open-label clinical study (NCT 02052596) of subjects aged 50 years and older. Subjects in Group 1 received BOOSTRIX and the first dose of SHINGRIX at Month 0 and the second dose of SHINGRIX at Month 2 (n = 412; concomitant administration group). Subjects in Group 2 received BOOSTRIX at Month 0, the first dose of SHINGRIX at Month 2, and the second dose of SHINGRIX at Month 4 (n = 418; separate administration control group). The mean age of the subjects was 63 years; 54% were female. The majority of subjects were White (87%), followed by Black (11%), and other racial groups; 2% were of American Hispanic or Latino ethnicity.
The immune responses to BOOSTRIX (anti-D, anti-T, and antibodies to pertussis antigens) were measured 1 month after administration of the single dose of BOOSTRIX. The immune response to SHINGRIX was measured by anti-gE Ab concentrations 1 month after the second dose of SHINGRIX. Concomitant administration showed no evidence for interference in the immune response to the antigen contained in SHINGRIX or the antigens contained in BOOSTRIX, with the exception of one of the pertussis antigens (pertactin), which did not satisfy the noninferiority criterion: the UL of the 95% CI for the adjusted GMC ratio (separate administration control group/concomitant administration group) for anti-pertactin antibody was 1.58 (noninferiority criterion <1.5). The clinical significance of the reduced immune response to pertactin is unknown.
REFERENCES
2. Wassilak SGF, Roper MH, Kretsinger K, and Orenstein WA. Tetanus Toxoid. In: Plotkin SA, Orenstein WA, and Offit PA, eds. Vaccines. 5th ed. Saunders; 2008:805-839.
3. Vitek CR and Wharton M. Diphtheria Toxoid. In: Plotkin SA, Orenstein WA, and Offit PA, eds. Vaccines. 5th ed. Saunders; 2008:139-156.
4. Skoff TH, Blain AE, Watt J, et al. Impact of the US maternal tetanus, diphtheria, and acellular pertussis vaccination program on preventing pertussis in infants <2 months of age: a case-control evaluation. Clin Infect Dis. 2017; 65 (12): 1977-83.
5. Bellido-Blasco J, Guiral-Rodrigo S, Míguez-Santiyán A, Salazar-Cifre A, González-Morán F. A case-control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016. Euro Surveill. 2017;22(22).
6. Saul N, Wang K, Bag S, Baldwin H, Alexander K, Chandra M, et al. Effectiveness of maternal pertussis vaccination in preventing infection and disease in infants: The NSW Public Health Network case-control study. Vaccine. 2018;36(14):1887-1892.
7. Uriarte PS, Rodríguez SSJ, Sancristobal IG, Agirre NM. Effectiveness of dTpa vaccination during pregnancy in preventing whooping cough in infants under 3 months of age. Bizkaia, Basque Country, Spain. Heliyon. 2019;5(2):e01207.
8. Andrews A, Campbell H, Riberio S, Fry N, Amirthalingham G. Boostrix-IPV Report: Effectiveness of Maternal Pertussis Vaccination in Prevention of Confirmed Pertussis in Children in England Using the Screening Method Report to 30 September 2018. Public Health England. Unpublished. 2020.