Analysis of adverse events of potential autoimmune aetiology in a large integrated safety database of AS04 adjuvanted vaccines

Abstract

Newly licensed vaccines against human papillomavirus (HPV) and hepatitis B (HBV), and several vaccines in development, including a vaccine against genital herpes simplex virus (HSV), contain a novel Adjuvant System, AS04, composed of 3-O-desacyl-4' monophosphoryl lipid A and aluminium salts. Given the background incidence of autoimmune disorders in some of the groups targeted for immunisation with these vaccines, it is likely that autoimmune events will be reported in temporal association with vaccination, even in the absence of a causal relationship. The objective of this integrated analysis was to assess safety of AS04 adjuvanted vaccines with regard to adverse events (AEs) of potential autoimmune aetiology, particularly in adolescents and young adults. All randomised, controlled trials of HPV-16/18, HSV and HBV vaccines were analysed in an integrated analysis of individual data (N = 68,512). A separate analysis of the HPV-16/18 vaccine trials alone was also undertaken (N = 39,160). All data were collected prospectively during the vaccine development programmes (mean follow-up of 21.4 months), and included in the analysis up to a pre-defined data lock point. Reporting rates of overall autoimmune events were around 0.5% and did not differ between the AS04 and control groups. The relative risk (AS04/control) of experiencing any autoimmune event was 0.98 (95% confidence intervals 0.80, 1.21) in the integrated analysis and 0.92 (0.70, 1.22) in the HPV-16/18 vaccine analysis. Relative risks calculated overall, for disease category or for individual events were close to 1, and all confidence intervals around the relative risk included 1, indicating no statistically significant difference in event rates between the AS04 and control groups. This integrated analysis of over 68,000 participants who received AS04 adjuvanted vaccines or controls demonstrated a low rate of autoimmune disorders, without evidence of an increase in relative risk associated with AS04 adjuvanted vaccines.