Influence of predispositions on post-traumatic stress disorder: does it vary by trauma severity?

BACKGROUND: Only a minority of trauma victims (<10%) develops post-traumatic stress disorder (PTSD), suggesting that victims vary in predispositions to the PTSD response to traumas. It is assumed that the influence of predispositions is inversely related to trauma severity: when trauma is extreme predispositions are assumed to play a secondary role. This assumption has not been tested. We estimate the influence of key predispositions on PTSD induced by an extreme trauma - associated with a high percentage of PTSD - (sexual assault), relative to events of lower magnitude (accidents, disaster, and unexpected death of someone close). METHOD: The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) is representative of the adult population of the USA. A total of 34 653 respondents completed the second wave in which lifetime PTSD was assessed. We conducted three series of multinomial logistic regressions, comparing the influence of six predispositions on the PTSD effect of sexual assault with each comparison event. Three pre-existing disorders and three parental history variables were examined. RESULTS: Predispositions predicted elevated PTSD risk among victims of sexual assault as they did among victims of comparison events. We detected no evidence that the influence of predispositions on PTSD risk was significantly lower when the event was sexual assault, relative to accidents, disasters and unexpected death of someone close. CONCLUSIONS: Important predispositions increase the risk of PTSD following sexual assault as much as they do following accidents, disaster, and unexpected death of someone close. Research on other predispositions and alternative classifications of event severity would be illuminating.

Stability and suitability for storage and distribution of Ad26.ZEBOV/MVA-BN®-Filo heterologous prime-boost Ebola vaccine.

The stability profile of a vaccine has important implications for storage, cold chain management and field deployment. The heterologous prime-boost Janssen Ebola vaccine regimen demonstrated an acceptable safety profile and durability of Ebola-specific immune responses in Phase I studies in healthy adults. Potency (infectious titre) of both components of the Ad26.ZEBOV/MVA-BN-Filo regimen were assessed using qPCR-based potency assay and flow cytometry during real-time and accelerated stability studies, conducted between -80 °C and 25 °C. Additionally, vaccine potency was assessed following agitation, temperature cycling, freeze-thawing and while in the injection system. Ad26.ZEBOV remained stable for 24 months when frozen and at 2-8 °C; MVA-BN-Filo remained stable for 24 months frozen and 12 months at 2-8 °C. Potency of both vaccines was maintained during temperature cycling, agitation and freeze-thawing. When exposed to high temperatures (up to 40 °C) in a syringe/needle both vaccines remained stable for at least 6 h. The vaccines are expected to maintain potency for 36 months when frozen (based on extrapolation of observed stability). The findings of this study indicate that the stability of the Ad26.ZEBOV/MVA-BN-Filo is likely suitable for field deployment in regions at risk of Ebola outbreaks, where cold chain maintenance is challenging owing to infrastructure and resource limitations.