Date Published: February 14, 2018
Publisher: Public Library of Science
Author(s): Vania Giacomet, Michela Masetti, Pilar Nannini, Federica Forlanini, Mario Clerici, Gian Vincenzo Zuccotti, Daria Trabattoni, Ravi Jhaveri.
HBV vaccine induces protective antibodies only in 23–56% of HIV-infected children. The aim of our study is to evaluate the immunologic effects of a booster dose of HBV vaccine in HIV-infected youth.
53 young HIV-infected patients in whom HBV vaccination did not elicit protective Ab titers were enrolled. All patients were on ART with optimal immunological and viral response.
All patients received a booster dose of HBV vaccine (HBVAXPRO 10 μg i.m.). HBV-specific Ab titer, viral load and CD4+ T cells were measured at baseline (T0), T1, T6 and T12 months. In a subgroup of 16 patients HBV-specific cell mediated immune responses were evaluated at baseline, at T1 and T6.
The booster dose induced seroconversion in 51% of patients at T1, 57% at T6, and49% at T12; seroconversion rate was significantly correlated with CD4+T cells at T0 and to the CD4 nadir. The booster dose induced HBV-specific cell mediated immunity at T6 mainly in Responders (Rs): Effector Memory CD8+T cells, HBV-specific TNFα-, IFNγ-, granzyme secreting CD8+ T cells and IL2-secreting CD4+ T cells were significantly increased in Rs compared to T0. In Non Responders (NRs), HBV-specific IL2-secreting CD4+ T cells, Central and Effector Memory CD8+ T cells were the only parameters modified at T6.
Seroconversion induced by a booster dose of vaccine correlates with the development of T cell immunological memory in HIV-infected patients who did not respond to the standard immunization. Alternate immunization schedules need to be considered in NRs.
Chronic viral hepatitis has become a major source of comorbidity in Human Immunodeficiency Virus (HIV) infected populations, with improved survival due to the success of antiretroviral therapy (ART). A high incidence of both acute and chronic HBV infection is seen in HIV-infected patients, probably because both viruses share the same route of transmission . Notably, HIV complicates the natural course of HBV, resulting in greater levels of HBV viremia, higher rate of HBV reactivation, chronic hepatitis and increased incidence of cirrhosis and liver-related mortality [2,3].
Current guidelines recommend a 3-doses HBV vaccine regimen for children and adolescents <19 year-old and it has been demonstrated that this regimen delivers a good response, which is estimated to be around 90% [20–22]. However, immunization response to standard HBV vaccine regimen drops to 28–78% in HIV-infected children and it generally fails to elicit a strong and long-lasting immunity . Studies have shown that re-vaccination or doubling doses of vaccine are able to increase seroconversion rates in HIV-infected children, especially in the settings of well-controlled viremia and immune recovery [23,24]. Source: http://doi.org/10.1371/journal.pone.0192638