1931. Persistence of the Immune Response to an Adjuvanted Herpes Zoster Subunit Vaccine in Healthy Older Adults: Modeling of Vaccine-induced Immune Response, Data from a 6-year Follow-up Study
Session: Poster Abstract Session: Vaccines: Varicella/Zoster
Saturday, October 10, 2015
Room: Poster Hall

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

Himal Lal, MD1, Roman Chlibek, MD, PhD2, Karlis Pauksens, MD, PhD3, Tino F. Schwarz, PhD4, Jan H. Richardus, MD, PhD5, Gini G.C. Van Rijckevorsel, MD, MSc, PhD6, Thomas C. Heineman, MD, PhD1 and Grégory Catteau, MSc7, (1)GSK Vaccines, King of Prussia, PA, (2)University of Defence, Hradec Kralove, Czech Republic, (3)Uppsala University Hospital, Uppsala, Sweden, (4)Stiftung Juliusspital, Wuerzburg, Germany, (5)Municipal Public Health Service Rotterdam-Rijnmond, Rotterdam, Netherlands, (6)Public Health Service (GGD) Amsterdam, Amsterdam, Netherlands, (7)GSK Vaccines, Wavre, Belgium

Disclosures:

H. Lal, GSK group of companies: Employee and Shareholder , Salary

R. Chlibek, GSK group of companies: Investigator , Research support
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

Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.