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

Comparison of hepatitis B surface antibody levels induced by the pentavalent DTwP-HB-Hib versus the hexavalent DTaP-HB-Hib-IPV vaccine, administered to infants at 2, 4, 6, and 18 months of age, following monovalent hepatitis B vaccination at birth

BACKGROUND

In Thailand, the hepatitis B (HB) vaccine is administered as a tetravalent vaccine (DTwP-HB) to all infants at 2, 4, and 6 months of age, following an initial vaccination with a monovalent HB vaccine at birth. As part of ongoing vaccine evaluation, we aimed to compare the hepatitis B immunogenicity profiles of children who had received either the pentavalent (DTwP-HB-Hib) or the hexavalent (DTaP-HB-Hib-IPV) vaccine.

METHODS

Two groups of infants, whose mothers previously received the tetanus-diphtheria-acellular pertussis vaccine (Tdap), were randomly vaccinated with either pentavalent or hexavalent vaccine at 2, 4, 6, and 18 months of age, following monovalent HB vaccine at birth. Blood samples were obtained at birth, one-month post-primary series immunization (mo 7), pre-booster (mo 18), one-month post-booster (mo 19), and six months post-booster (mo 24). The third group of infants, whose mothers did not receive Tdap, was vaccinated with DTwP-HB-Hib (EPI pentavalent group). Levels of HBsAg, anti-HBc, and anti-HBs were evaluated by means of an automated Chemiluminescent Microparticle Immunoassay.

RESULTS

Anti-HBs levels of ≥10 mIU/ml were achieved in 99.2% (hexavalent group), 99.2% (pentavalent group), and 98.5% (EPI pentavalent group) of infants, after four-dose immunization (at 0, 2, 4, 6 months of age). One month after the additional dose given at 18 months of age, anti-HBs levels of ≥10 mIU/ml were observed in 100% (hexavalent group), 99.2% (pentavalent group), and 93.8% (EPI pentavalent group) of infants. At 24 months of age, higher percentages of infants achieving anti-HBs levels ≥10 mIU/ml were found in the hexavalent group (98.3%) compared to the pentavalent group (86.5%).

CONCLUSIONS

Both vaccines were effective in inducing anti-HBs levels of ≥10 mIU/ml, and therefore either can be used as a single formula booster at 18 months of age to simplify vaccine administration under the Expanded Program on Immunization in Thailand.

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

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

Immunogenicity and safety of primary and booster vaccination with 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens in a hexavalent DTPa-HBV-IPV/Hib combination vaccine in comparison with the licensed Infanrix hexa

Safety and immunogenicity of 2 investigational formulations of diphtheria, tetanus and Haemophilus influenzae type b antigens of the combined diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliomyelitis-Hib vaccine (DTPa-HBV-IPV/Hib) were evaluated in a Primary (NCT01248884) and a Booster vaccination (NCT01453998) study.

In the Primary study, 721 healthy infants (randomized 1:1:1) received 3 doses of DTPa-HBV-IPV/Hib formulation A (D_AT_APa-HBV-IPV/Hib), or B (D_BT_BPa-HBV-IPV/Hib) or the licensed DTPa-HBV-IPV/Hib vaccine (Infanrix hexa, GSK; control group) at 2, 3, 4 months of age. Infants were planned to receive a booster dose at 12–15 months of age with the same formulation received in the Primary study; however, following high incidence of fever associated with the investigational formulations in the Primary study, the Booster study protocol was amended and all infants yet to receive a booster dose (N = 385) received the licensed vaccine.

In the Primary study, non-inferiority of 3-dose vaccination with investigational formulations compared with the licensed vaccine was not demonstrated due to anti-pertactin failing to meet the non-inferiority criterion. Post-primary vaccination, most infants had seroprotective levels of anti-diphtheria (100% of infants), anti-tetanus antigens (100%), against hepatitis B (≥ 97.5% across groups), polyribosyl-ribitol-phosphate (≥ 88.0%) and poliovirus types 1–3 (≥ 90.5%). Seropositivity rates for each pertussis antigen were 100% in all groups.

Higher incidence of fever (> 38°C) was reported in infants receiving the investigational formulations (Primary study: 75.0% [A] and 72.1% [B] vs 58.8% [control]; Booster study, before amendment: 49.4% and 46.6% vs 37.4%, respectively).

The development of the investigational formulations was not further pursued.