Adesão e imunogenicidade aos esquemas ultra-acelerado e acelerado de vacinação contra hepatite B entre homens em situação de rua

Abstract

Considering the long duration of the classic hepatitis B virus (HBV) vaccination schedule, with the common loss of vaccine follow-up, alternative schemes have been proposed for vulnerable populations. The aim of this study was to evaluate the adhesion and immunogenicity of HBV vaccine in homeless men (HSR) under the accelerated (E-UA) and accelerated (E-A) vaccination regimens. Randomized, two-arm, controlled, non-inferiority trial was performed by identifying HBV-susceptible HSR, which were allocated at a 1:1 ratio for E-UA (doses at 0, 7, and 21 days) and E-A (doses at 0, 1 and 2 months). For those who completed the proposed regimen, immunogenicity assessment was performed at 30, 60 and 90 days after the last dose of each regimen. Study approved by the Research Ethics Committee and registered in the Brazilian Clinical Trials Registry (ReBEC) platform. Of the 156 screened HSR, 67 were excluded; 35 (22.4%; 95% CI: 16.6-29.6%) for having some marker of HBV exposure (2 HBsAg/positive total anti-HBc; 15 positive isolated total anti-HBc and 18 anti-HBc/anti-HBs positive) and 32 (20.5%; 95% CI: 14.9-27.5%) for isolated immunity. Of the 89 susceptible identified, 18 (20.2%) were absent at the start of the intervention and the 71 eligible were randomized and allocated to E-UA (n= 35) and E-A (n= 36). The E-UA adherence rate was 94.3% (95% CI: 81.4 -98.4%) and the E-A rate was 63.9% (95% CI: 47.6-77.5%), and E-UA was associated with higher vaccine adherence rate (RR: 1.3; 95% CI: 1.1-1.7). In the analysis of the geometric mean titre (MGT) of anti-HBs, 30 days after the last dose of the vaccine, the group submitted to E-UA had a MGT of 147.6 mIU/mL versus 224.8 mIU/mL of those submitted to the vaccine. E-A (p-value= 0.985). After 60 days, the MGT for E-UA patients was 231.7 mIU/mL versus 211.2 mIU/mL for E-A (p-value= 0.572). After 90 days, the MGT between E-UA and E-A was 259.6 mIU/mL versus 233.1 mIU/mL (p-value= 0.548). In the analysis of adequate immune response (anti-HBs titers ≥10 mIU/mL), after 30 days, 88.0% of E-UA individuals and 94.7% of E-A individuals responded to the vaccine (p-value = 0.622). After 60 days, the response to the vaccine was similar between the E-UA and E-A groups (95.5% versus 92.9%; p-value = 1,000). After 90 days, this rate was 94.7% for the E-UA group and 100.0% for the E-A group (p-value = 1,000). The use of E-UA and E-A was effective with regard to early immunogenicity. Regarding adherence, E-UA was statistically identified as the best vaccination schedule option in this study.