Background: GSK Vaccines' investigational herpes zoster (HZ) subunit vaccine (HZ/su) containing varicella-zoster virus glycoprotein E (gE; 50 μg) and the AS01B Adjuvant System demonstrated 97.2% efficacy in reducing the risk of HZ in older adults (≥50 years of age).1 While the duration of protection is currently unknown, persistence of the immune response following 2-dose vaccination with HZ/su in healthy older adults was observed for up to 6 years post-dose 1 in a separate study.2 Here, 3 statistical models were used to predict whether the immune response to vaccination with HZ/su persists beyond 6 years.
Methods: Vaccine-induced immune response data from healthy older adults (≥60 years of age) who had received 2 doses (2 months apart) of HZ/su in a previous trial conducted in the Czech Republic, Germany, Sweden and the Netherlands were recorded for up to 6 years post-dose 1 (NCT00434577 and NCT01295320). To predict the persistence of the immune responses beyond the 6 years observed in the clinical trial, frequencies of gE-antigen-specific CD4+ T cells and serum anti-gE antibody concentrations from subjects who received 2 doses of HZ/su, were used to fit the piece-wise, power-law, and Fraser models.
Results: Six years post-dose 1, both cell-mediated and humoral immune responses were above baseline values (Figure 1). All 3 models predicted that both the cell-mediated and the humoral immune responses will persist (remain above the baseline values) beyond 6 years post-dose 1 (Figure 2). Irrespective of the model, for up to 10 years post-dose 1, at least a 2.4-fold increase was seen for the cell-mediated immune response and at least a 4.5-fold increase was seen for the humoral immune response compared to baseline values (Figure 3).
Conclusion: Modeling the immune response persistence based on the 6-year data predicts that vaccine-induced immune responses in healthy older adults will remain above baseline values for at least 10 years after 2-dose vaccination with HZ/su.
Funding: GlaxoSmithKline Biologicals SA
1Lal et al. NEJM 2015
2Lal et al. IDWeek 2014
GSK group of companies:
Pfizer: Speaker's Bureau , Speaker honorarium
Gilead: Investigator , Research grant
K. Pauksens, GSK group of companies: Investigator , Research support
T. F. Schwarz, GSK group of companies: Speaker's Bureau , Speaker honorarium
J. H. Richardus, GSK group of companies: Grant Investigator , Research support
G. G. C. Van Rijckevorsel, None
T. C. Heineman, GSK group of companies: Employee , Salary
G. Catteau, GSK group of companies: Employee , Salary