Immunogenicity and safety of a hexavalent pediatric vaccine in HIV-exposed infected and uninfected infants in Republic of South Africa

ABSTRACT

Human immunodeficiency virus (HIV)-exposed infants may be at increased risk of vaccine-preventable disease. This study was conducted as a post-licensure commitment in this population to evaluate the primary series, antibody persistence, and booster response to a licensed fully liquid hexavalent vaccine containing diphtheria (D), tetanus (T), acellular pertussis (aP), inactivated poliovirus (IPV), hepatitis B (HB), and Haemophilus influenzae type b antigens (PRP~T). This was a Phase III, open-label, randomized study conducted at a single center in the Republic of South Africa. The DTaP-IPV-HB-PRP~T vaccine was administered to HIV-exposed infected (Group A: N = 14) and HIV-exposed uninfected (Group B: N = 50) infants as a 6, 10, 14 week primary series with a toddler booster at 15–18 months of age. Immunogenicity of each antigen was measured using validated assays and vaccine reactogenicity was recorded using diary cards. The low number of HIV-exposed infected participants, due to widespread pre- and peri-natal retroviral treatment, meant that between-group comparisons should be treated with caution. In each group, primary series and booster immune seroprotection rates were strong, and pre-booster antibody persistence was good, although anti-HBs ≥10 mIU/mL in Group A was 78.6% post-primary series, 58.3% pre-booster, and 75.0% post-booster. There were no safety concerns. In conclusion, primary series and booster vaccination of the DTaP-IPV-HB-PRP~T vaccine were immunogenic and safe in HIV-exposed infected and uninfected infants. These results were comparable to historical data in healthy infants and toddlers.

KEYWORDS:

• booster
• hexavalent
• historical comparison
• HIV-exposed
• HIV-infected
• primary series
• vaccine

Acknowledgments

The authors thank the participants and their families for their generous contribution to advancing the knowledge of vaccination.

The authors would also like to acknowledge the study nurses and other staff at the study site, Sanofi Pasteur’s Global Clinical Immunology (GCI) laboratory (Swiftwater, PA, USA) for serological testing, and Fabrice Guitton (Sanofi Pasteur) for project management.

Dr Andrew Lane (Lane Medical Writing) provided medical writing assistance, funded by Sanofi Pasteur, in the preparation and development of the manuscript in accordance with the European Medical Writers Association guidelines and Good Publication Practice.

Disclosure of potential conflicts of interest

Clinical investigators (AK and SM) received fees from Sanofi Pasteur through their institution for the conduct of these clinical studies, but did not receive any direct payment from Sanofi Pasteur in this regard. They may have received expenses for conference attendance for the presentation of data from these studies.

Additional information

Funding

The study was funded by Sanofi Pasteur, Lyon, France.