BACKGROUND

Very limited data are available on the immunovirological outcomes after 13-valent pneumococcal conjugate vaccine (PCV13) in antiretroviral therapy (ART)-treated patients. The aim of this study was to assess the immune-virological outcomes in HIV-1-infected ART-treated patients on stable virological suppression who underwent pneumococcal conjugate vaccination.

METHODS

Retrospective, cohort study on ART-treated HIV-1-infected individuals, age at least 18 years, with three consecutive determinations of HIV-RNA less than 50 copies/ml before the administration of PCV13 (baseline) at San Raffaele Hospital and with at least two HIV-RNA values after vaccination.

RESULTS

Overall 1197 patients underwent PCV13 vaccination. During 6-month of follow-up (594 person-years of follow-up, PYFU), 12 confirmed virological failure and 35 viral blips were observed; the overall incidence rate of confirmed virological failure was 2.02 (95% confidence interval: 0.88-3.16) per 100-PYFU and the incidence rate of viral blips was 5.89 (95% confidence interval: 3.94-7.84) per 100-PYFU. Median CD4 cell count change from baseline at 6 months was +10 cells/μl (interquartile range -67, +111; P = 0.0002). Median change in CD4/CD8 ratio was +0.02 (interquartile range -0.06, +0.11; P < 0.001).

CONCLUSION

Viral blips and confirmed virological failures were rarely observed in patients on stable virological suppression in the first 6 months following vaccination with PCV13. In addition, no decrease of CD4 cell count and CD4/CD8 ratio was recorded.