Poor increase on HAV vaccination coverage among people living with HIV after an immunization-based intervention

ABSTRACT

Objectives To assess HAV serologic and vaccination status among people who live with HIV (PLWH), and to evaluate the impact of a vaccination-based strategy on HAV-negative patients in Seville, Spain. Methods Study with two time-overlapping phases (i) cross-sectional study of HAV immunity prevalence among PLWH followed at a Spanish hospital between August 2019 and March 2020. (ii) Patients seronegative for HAV, reliably unvaccinated were included in a before-and-after quasi-experimental study, with an intervention focused on HAV vaccination according to national recommendations in force. Results Six hundred and fifty-six patients were included, of which 111 [17%, 95% confidence interval (95% CI) 14–20%] were seronegative for HAV. Of these, 48 [43% (95% CI, 34–53%)] individuals were MSM. The absence of HAV immunity was attributed in 69 [62% (95% CI, 52–71%)] patients to non-referral to vaccination, followed by lack of achievement of a correct vaccination scheme [n=26;23% (95% CI, 16–32%)]. After the program implementation, 96 [15% (95% CI, 12–18%)] individuals were seronegative (17% vs. 15%, p=0.256), of whom 42 [41% (95% CI, 32–51%)] were MSM. The absence of immunity after the intervention was mainly attributed to adherence failure in 23 [24.0% (95% CI, 15.8–33.7%)] patients, on-course immunization scheme in 34 [33% (95% CI, 24–43%)] individuals and pending appointment at the vaccine delivery unit in 20 [20.8% (95% CI, 13.2–30.3%)] patients. Conclusions A sizeable proportion of PLWH remains susceptible for HAV infection in future outbreaks. A program based on referral to the vaccine delivery unit yields poor results, largely due to program adherence failures. New strategies are needed to increase HAV vaccination coverage. Resumen Objetivos Evaluar la prevalencia de inmunidad frente al VHA en personas que viven con VIH así como el impacto de una intervención basada en la vacunación de pacientes seronegativos frente al VHA. Métodos Estudio con dos fases solapadas en el tiempo 1) transversal de prevalencia de inmunidad frente al VHA en personas que viven con VIH seguidas en un hospital de tercer nivel, entre agosto de 2019 y el inicio de las medidas nacionales de contención de la epidemia por SARS-CoV-2, marzo de 2020. 2) Cuasiexperimental, con una intervención centrada en la vacunación frente a VHA de pacientes seronegativos, en la unidad responsable de esta. Resultados Ciento once (17%, [95% IC, 14-20%]) de los 656 pacientes incluidos eran seronegativos frente al VHA. Las principales causas de la ausencia de inmunidad fueron 69 (62% [95% IC, 52-71%]) individuos no derivados a la unidad responsable de la vacunación;26 pacientes (23% [95% CI, 16-32%]) no completaron el esquema vacunal. Tras la intervención, 96 (15% [95% IC, 12-18%]) pacientes continuaron siendo seronegativos frente al VHA (comparada con la prevalencia basal, p=0,256), 42 (18% [95% IC, 13-23%]) eran HSH. Las principales causas de la ausencia de inmunidad fueron 26 (23% [95% IC, 15-32%]) individuos presentaron fallos de adherencia al circuito vacunal;34 (33% [95% IC, 24-43%]) pacientes habían recibido una sola dosis;22 (22% [95% IC, 14-31%]) seguían sin una primera valoración por parte de la unidad responsable de la vacunación. Conclusiones Una proporción considerable de personas que viven con VIH, particularmente HSH, sigue siendo susceptible a la infección por VHA. La derivación sistemática a la unidad responsable de la vacunación se traduce en modestos incrementos de la prevalencia de inmunidad. Son necesarias nuevas estrategias para aumentar la cobertura vacunal.