Immunogenicity and Safety of a Pentavalent Diphtheria, Tetanus, Acellular Pertussis, Inactivated Poliovirus, Haemophilus influenzae Type b Conjugate Combination
Vaccine (Pentaxim™) with Hepatitis B Vaccine

Manuscript received: April 13, 2009;
Initial review: May 12, 2009;
Accepted: September 30, 2009.

ClinicalTrials.gov identifier: NCT00259337

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~T vaccine (PentaximTM) 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 ³0.15 mg/mL and 90.0% had titers ³1.0 mg/mL; the anti-PRP GMT was 4.1 µg/mL. Seroprotection rates for diphtheria and tetanus (³0.01 IU/mL) were 99.1% and 100%; and 100%,99.1% and 100%, for polio types 1,2 and 3 (³8 [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~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.

Keywords: pentavalent combined vaccine, primary series, EPI schedule, immunogenicity, safety.

Vaccines combining whole cell Bordetella pertussis (wP) antigens with diphtheria (D) and tetanus (T) toxoids (DTwP) have been central to the WHO expanded program of immunization (EPI). The valences included in modern combination vaccines reflect current EPI recommendations. In India, DTwP has been a part of the Universal Immunization Program (UIP) since 1985, and the Indian Academy of Pediatrics (IAP) recommends Hib vaccination and inactivated polio vaccine (IPV) for all children who can afford it after one-to-one discussion with parents(1). The use of combination vaccines reduces the number of required injections, the number of clinic visits and the discomfort for children. A number of DTwP-based combination vaccines containing Hib have recently been evaluated in India(2).

Healthy fullterm (³37 weeks) infants weighing ³2.5 kg at birth were eligible. Each subject received the DTaP-IPV//PRP~T study vaccine (6,10,14 weeks of age) and hepatitis B (Hep B) vaccine (0,6,14 or at 6,10,14 weeks of age) according to the Indian National Immunization schedule and the clinical practice in each study center. A physical examination and medical review were performed before enrolment, and the inclusion and exclusion criteria were verified. Exclusion criteria included congenital or acquired immunodeficiency; immunosuppressive therapy; systemic hypersensitivity to any vaccine component; chronic illness that could interfere with trial conduct/completion; previous administration of blood or blood-derived products; any vaccination preceding the trial vaccination (except Bacille Calmette-Guérin [BCG] and hepatitis B vaccination); history of, or vaccination against, diphtheria, tetanus, pertussis, poliomyelitis, Hep B or Hib; thrombocytopenia/bleeding disorder contraindicating intramuscular vaccination; and, history of seizures.

The pentavalent vaccine (batch Z2044-1, Pentaxim™) was produced and supplied by Sanofi Pasteur, France, and stored between 2ºC and 8ºC. Each 0.5 mL dose of DTaP-IPV//PRP~T contained ³30 IU (25Lf) of diphtheria toxoid, ³40 IU (10Lf) of tetanus toxoid, 25 µg of pertussis toxoid (PT), 25 µg of filamentous hemagglutinin (FHA), 40 D antigen units (DU) of poliovirus type 1 (Mahoney), 8 DU of poliovirus type 2 (MEF-1), 32 DU of poliovirus type 3 (Saukett), and 10 µg polyribosyl-ribitol-phosphate (PRP) Hib capsule polysaccharide conjugated to tetanus protein. The lyophilized PRP~T component was reconstituted with the liquid DTaP-IPV vaccine immediately before vaccination. The recombinant Hep B vaccine (Euvax B™, LG Life Sciences, Iksan, Korea, batch UVA05005), contained 10 µg of recombinant HBsAg; this vaccine is licensed and commercially available in India. The pentavalent vaccine and the hepatitis B vaccine were administered by intramuscular injection into the right and left anterior thigh, respectively.

Safety data were only collected for the pentavalent vaccine. Following an initial assessment by the Investigator of immediate adverse events occurring in the 30 minutes after each vaccination, parents/legal guardians recorded solicited injection site reactions (redness, swelling and tenderness) and solicited systemic reactions (fever [axillary temperature ³37.4ºC], vomiting, abnormal crying, drowsiness, loss of appetite and irritability) on diary cards daily for 8 days after each vaccination. Unsolicited injection site and systemic reactions (with onset date, resolution, and intensity) were recorded for 30 days after each vaccination. Serious adverse events (SAEs) were reported throughout the conduct of the study. Solicited and unsolicited local and systemic adverse events were graded according to the scales described below as mild, moderate, or severe. Mild, moderate or severe tenderness were defined as ‘minor reaction when injection site is touched’, ‘cries and protests when injection site is touched’, and ‘cries when injected limb is moved, or the movement of the injected limb is reduced’. For erythema and swelling, a diameter of <2.5 cm was graded as mild, 2.5 to 5 cm as moderate and ³5 cm as severe. Mild, moderate and severe fever were defined as axillary temperature ³37.4ºC to 37.9ºC, ³38ºC to 38.9ºC, and ³39ºC, respectively.

Seroprotection and vaccine response rates were calculated with their corresponding 95% confidence intervals (CI) using the exact binomial method. Pre-defined seroprotection levels were: anti-PRP ³0.15 and ³1.0 µg/mL; anti-polio ³8 (1/dil); anti-diphtheria and anti-tetanus ³0.01 IU/mL. The pertussis antigens were assessed using ³4-fold and ³2-fold increases in antibody concentration from pre- to post-vaccination state.

The seroprotection and vaccine response rates for the study vaccine and historical control study are summarized in Table I. In addition to the criteria presented in Table 1, 90.0% of subjects had anti-PRP ³1.0 µg/mL after the third dose, and 97.1% and 92.4% of subjects had ³2-fold increases in antibody titer for PT and FHA. The tetanus seroprotection rate was very high before the first injection, with 99.5% of subjects having anti-tetanus antibody titers ³0.01 IU/mL and 97.2% having titers ³0.1 IU/mL. GMTs increased strongly following the primary vaccination (Table II). Fig.1 shows a strong, linear increase in antibody titers for anti-PRP antibodies (µg/mL); a similar effect was seen for the remaining antigens.

Table I



Seroprotection/Vaccine Response Rates to DTaP-IPV/PRP~T Pentavalent Vaccine

Table II



Geometric Mean Titers (GMTs) Before the First Dose and One Month After the Third 

Dose of the Study Vaccine

 

Fig.1 RCDCs for anti-PRP antibody titers before (6 weeks of age) and 1 month after primary vaccination (18 weeks of age).

Safety and Reactogenicity

Solicited symptoms after any dose and after each dose are summarized in Table III. Injection site tenderness was the most common symptom, but was severe only after two injections (0.3% of doses). The incidence of erythema and swelling was also low. All solicited injection site reactions occurred within 3 days after vaccination except one case of erythema/redness that occurred between Days 4 and 7. The percentage of subjects with a specific adverse reaction did not increase with subsequent doses. Fever was the most frequent systemic reaction, with at least one episode being reported by 33.0% of subjects (15.3% of doses), followed by irritability and drowsiness. Only two subjects (0.9%) had severe fever (³39.0ºC axillary temperature) and only one case of drowsiness was severe.

Table III



Solicited Local Adverse Reactions And Systemic Reactions That Occurred Within 8 Days (Days 0-7) 

After Each Dose and After Any Dose of Pentavalent Vaccine	

This clinical study evaluated the immunogenicity and safety of a DTaP-IPV//PRP~T combination vaccine (Pentaxim™) for primary immunization at 6,10,14 weeks of age, with a monovalent recombinant hepatitis B vaccine (Euvax BTM) given at either 6,10,14 weeks of age or 0,6,14 weeks of age. No control group wP was included since wP vaccines are routinely available in India, meaning that participation in such an arm of the study would have offered no benefit to the infant. Instead, the study design included a descriptive comparison to a historical control study group given the same vaccine at 2,3,4 months of age in France, where this vaccine has been routinely used(9). At the time of the study, no historical clinical data on the immunogenicity of this vaccine given at 6,10,14 weeks of age were available.

As there are no recognized serological correlates of protection for pertussis, 4-fold increases from pre- to post-vaccination were used to evaluate the anti-PT and FHA response. These data and the strong increase in GMTs accord with anti-PT and anti-FHA responses to this 2-component acellular pertussis vaccine reported in 36 clinical trials conducted in 17 countries in Europe, North and South America, Africa and Asia that have included nearly 10,000 subjects(14). The long-term effectiveness of the pentavalent vaccine on pertussis incidence has been documented over the past 10 years by the National Surveillance Program in Sweden using a 3, 5, 12 month schedule(15,16). Although the schedule in Sweden differs from that in India, we believe that the Swedish surveillance data are applicable to the EPI administration schedule since high immunogenicity has been demonstrated from a range of primary series schedules(11-13). These data have shown that routine primary vaccination with aP vaccines, including the present pentavalent vaccine (PentaximTM), has resulted in a marked decrease in the incidence of pertussis cases after the second and third doses and that protection remains high after the third dose for 8 to 9 years(17). In addition, the WHO position paper on aP vaccines(7) states that ‘‘although most efficacy and effectiveness studies on aP vaccines have been conducted in industrialized countries, the new DTaP vaccines are expected to be efficacious in all regions of the world.’’

Competing interest: EO is an employee of Sanofi Pasteur which manufactures PentaximTM.

21. Olin P, Rasmussen F, Gustafsson L, Hallander H, Heijbel H. Randomised controlled trial of two-component, three component, and five component acellular pertussis vaccines compared with whole-cell pertussis vaccine. Lancet 1997; 350: 1569-1577.