Delayed BCG vaccination results in minimal alterations in T cell immunogenicity of acellular pertussis and tetanus immunizations in HIV-exposed infants.

Abstract

BACKGROUND:

Bacille Calmette-Guerin (BCG) is effective in preventing disseminated tuberculosis (TB) in children but may also have non-specific benefits, and is thought to improve immunity to unrelated antigens through trained innate immunity. In HIV-infected infants, there is a risk of BCG-associated adverse events. We aimed to explore whether delaying BCG vaccination by 8 weeks, in utero or perinatal HIV infection is excluded, affected T-cell responses to B. pertussis (BP) and tetanus toxoid (TT), in HIV-exposed, uninfected infants.

METHODS:

Infants were randomized to receive BCG vaccination at birth or 8 weeks of age. At 8 and 14 weeks, T cell proliferation and intracellular cytokine (IL-2, IL-13, IL-17, and IFN-γ) expression was analyzed in response to BP, TT and Staphylococcal enterotoxin B (SEB) antigens.

RESULTS:

Delaying BCG vaccination did not alter T-cell proliferation to BP or TT antigens. Infants immunized with BCG at birth had higher CD4+ T cell proliferation to SEB at 14 weeks of age (p=0.018). Birth-vaccinated infants had increased CD8+ IL-2 expression in response to BP, but not TT or SEB, at 8 weeks. Infants vaccinated with BCG at 8 weeks had significantly lower IL-13 expression by BP-specific CD4+ and CD8+ T cells at 14 weeks (p=0.032 and p=0.0035, respectively). There were no observed differences in multifunctional cytokine response to TT, BP or SEB between infants vaccinated with BCG at birth versus 8 weeks of age.

CONCLUSION:

Delaying BCG vaccination until 8 weeks of age results in robust T-cellular responses to BP and TT in HIV-exposed infants.

CLINICAL TRIAL REGISTRY:

NCT02062580.

• Authors: Anna K Blakney, Christophe Toukam Tchakoute, Anneke C Hesseling, Elvis B Kidzeru, Christine E Jones, Jo-Ann S Passmore, Donald L Sodora, Clive M Gray, Heather B Jaspan
• Journal: Vaccine (Vaccine) Vol. 33 Issue 38 Pg. 4782-9 (Sep 11 2015) ISSN: 1873-2518 [Electronic] Netherlands
• PMID: 26259542 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical References

• BCG Vaccine
• Cytokines
• Pertussis Vaccine
• Tetanus Toxoid

Topics

• BCG Vaccine (administration & dosage)
• Cell Proliferation
• Cytokines (biosynthesis)
• Environmental Exposure
• Female
• HIV Infections
• Humans
• Immunization Schedule
• Infant
• Male
• Pertussis Vaccine (administration & dosage, immunology)
• T-Lymphocytes (immunology)
• Tetanus Toxoid (administration & dosage, immunology)
• Time Factors