Arya BK, Bhattacharya SD, Sutcliffe CG, Saha MK, Bhattacharyya S, Niyogi SK, Moss WJ, Panda S, Das RS, Mallick M, Mandal S. Immunogenicity and safety of two doses of catch-up immunization with Haemophilus influenzae type b conjugate vaccine in Indian children living with HIV.
Vaccine 2016;
34:2267-74. [PMID:
26988256 DOI:
10.1016/j.vaccine.2016.03.012]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/01/2016] [Accepted: 03/04/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND
Children living with HIV are at increased risk of disease from Haemophilus influenzae type b (Hib). Data are limited on the immunogenicity of a two-dose, catch-up schedule for Hib conjugate vaccine (HibCV) among HIV-infected children accessing antiretroviral therapy (ART) late.
OBJECTIVES
The objectives of the study were to: (1) evaluate baseline immunity to Hib and the immunogenicity and safety of two doses of HibCV among HIV-infected Indian children; and (2) document the threshold antibody level required to prevent Hib colonization among HIV-infected children following immunization.
METHODS
We conducted a prospective cohort study among HIV-infected children 2-15 years of age and HIV-uninfected children 2-5 years of age. HIV-infected children received two doses of HibCV and uninfected children received one. Serum anti-Hib PRP IgG antibodies were measured at baseline and two months after immunization in the HIV-infected children. Nasopharyngeal (NP) swabs were collected at baseline and follow-up.
RESULTS
125 HIV-infected and 44 uninfected children participated. 40% of HIV-infected children were receiving ART and 26% had a viral load >100,000 copies/mL. The geometric mean concentration of serum anti-Hib PRP antibody increased from 0.25 μg/mL at baseline to 2.65 μg/mL after two doses of HibCV, representing a 10.6-fold increase (p<0.0001). 76% percent of HIV-infected children mounted an immune response. Moderate or severe immune suppression, trimethoprim/sulfamethoxazole prophylaxis, and lower baseline antibody levels were associated with lower post-vaccine serum anti-Hib PRP IgG antibodies. A serum anti-Hib PRP IgG antibody level ≥ 3.3 μg/mL was protective against Hib NP colonization. There were no differences in adverse events between HIV-infected and uninfected children.
CONCLUSION
Including a catch-up immunization schedule for older HIV infected children in countries introducing Hib vaccines is important. Older HIV-infected children with delayed access to ART and without suppressed viral loads mounted an adequate immune response following two doses of HibCV.
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