Persistence of Hepatitis B Immunity Following 3-dose Infant Primary Series in HIV-infected Thai Adolescents and Immunologic Response to Revaccination

Undetectable Anti-HBs Antibodies: Need of a Booster Dose for HIV-1-Infected Individuals

HBV vaccination effectively prevents HBV transmission and the development of liver cancer. Disease progression and liver-related complications are more common in HIV-1/HBV co-infected than HBV mono-infected individuals. A considerable body of literature, which will be reviewed here, indicates that response to HBV vaccine is suboptimal in HIV-1-infected individuals and that the poor maintenance of protective immunity to HBV vaccines in these individuals is an important medical issue. Several factors affect HBV vaccine response during HIV-1 infection including CD4+ T cell counts, B cell response, vaccine formulation, schedules, and timing of antiretroviral therapy (ART). The initial response to HBV vaccination also plays a critical role in the sustainability of antibody responses in both HIV-1-infected and uninfected vaccinees. Thus, regular follow-up for antibody titer and a booster dose is warranted to prevent HBV transmission in HIV-1 infected people.

Serological responses to revaccination against HBV in HIV-positive patients born in the era of nationwide neonatal HBV vaccination

BACKGROUND

Serological responses to revaccination against hepatitis B virus (HBV) are unclear in HIV-positive adults who had undergone neonatal HBV vaccination and whose antibodies against HBV had waned in the era of combination antiretroviral therapy (cART).

METHODS

Between 2000 and 2017, 666 HIV-positive men who have sex with men (MSM) who were born after 1986, when nationwide neonatal HBV vaccination programme was implemented in Taiwan, were included for analyses. A serological response was defined when a hepatitis B surface antibody (anti-HBs) titre ≥10 mIU/mL was measured 4-24 weeks after the third dose of HBV vaccination.

RESULTS

During the study period, 295 (48.7%) HIV-positive MSM (mean age, 23.2 years) who had lost HBV seroprotection were eligible for revaccination; 171 (58.0%) received at least 1 dose (20-μg) of HBV vaccine and 116 (39.3%) completed the 3-dose schedule. The serological response rate to 3 doses of HBV revaccination was 74.0% and the rate of high-titre response (anti-HBs titre ≥100 mIU/mL) was 46.0%. The CD4 count before the first dose (per 50-cell/μL increment, adjusted odds ratio, 1.14; 95% confidence interval, 1.01-1.29) was positively associated with the serological response. The incident rate of HBV infection was 9.2 per 1000 person-years of follow-up among the patients who were non-responders after revaccination.

CONCLUSIONS

Despite HBV vaccination in the neonatal period, the serological response rate to HBV revaccination in HIV-positive MSM was modest and could wane rapidly. Regular testing of anti-HBs should be integrated into the HIV care despite cART containing HBV-active agents.

Immune response to a Tdap booster in vertically HIV-infected adolescents

BACKGROUND

Pertussis cases have increased worldwide and knowledge on immune response and cytokine profile after Tdap vaccine in immunodeficient adolescents is scarce.

OBJECTIVE

To evaluate the immune response after Tdap in HIV-infected (HIV) and in healthy adolescents (CONTROL).

METHODOLOGY

Thirty HIV adolescents with CD4 cell counts >200 and 30 CONTROLs were immunized with Tdap, after a prior whole-cell DTP vaccine primary scheme. Blood samples were collected immediately before and after vaccine. Lymphocyte immunophenotyping was performed by flow cytometry; tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with tetanus toxoid and Bordetella pertussis and supernatants were assessed for cytokines by xMAP.

RESULTS

Mean age of HIV and CONTROL groups were 17.9 e 17.1 years, respectively. Pain at injection site was more intense in CONTROL group. HIV group had similar increase in tetanus antibodies at 28 days (geometric mean concentration, GMC, 15.6; 95% CI, 7.52-32.4) than CONTROL group (GMC, 23.1; 95% CI, 15.0-35.5), but lower diphtheria antibodies at 28 days (GMC, 2.3; 95% CI, 0.88-6.19) than CONTROL group (GMC, 16.4; 95% CI, 10.3-26.2); for pertussis, the percentage of individuals who seroconverted was lower in HIV than CONTROL group (HIV, 62.1% versus CONTROL, 100%; p = .002). Both groups built a cellular immune response to tetanus, with a Th2 (IL-4, IL-5 and IL-13) and Th1 (IFN-γ) response, with lower cytokine levels in HIV than in CONTROL group. Especially for pertussis, cellular and humoral responses were less intense in HIV adolescents, with a lower Th1 and Th17 profile and higher IL-10 levels. HIV-infected adolescents on viral suppression showed an enhanced immune response to all the three vaccine antigens, although still at lower levels if compared to CONTROL group.

CONCLUSIONS

Both groups tolerated well and built an immune response after Tdap. However, HIV-infected adolescents would probably benefit from more frequent booster doses.