Inactivation of Zika virus in plasma and derivatives by four different methods

Abstract

Zika virus (ZIKV) is an emerging arbovirus with increasing prevalence in recent years. To reduce the risk of ZIKV transmission by transfusion, some mitigation strategies were recommended based on pathogen reduction technologies for blood products. In this study, we aimed to study the efficacy of several common pathogen reduction methods in the inactivation of ZIKV. The fresh frozen plasma and derivatives were spiked with a high titer of ZIKV or Sindbis virus (SINV). Viral titers and ZIKV RNA were measured before and after the inactivation treatment by methylene blue (MB), solvent/detergent (S/D), pasteurization, and low pH. The mean ZIKV infectivity titers in plasma and derivatives were 7.08 ± 0.14, 5.17 ± 0.14, 7.08 ± 0.14, and 5.80 ± 0.14 log₁₀ TCID₅₀ /mL, respectively before MB, S/D, pasteurization, and low pH inactivation. We found no detectable ZIKV RNA after five successive passages of inoculation on host cells, indicating there is no infectivity after inactivation. Similar inactivation results were observed for SINV. In conclusion, we achieved robust ZIKV inactivation through the four inactivation procedures in several blood products. These findings suggest that the pathogen reduction technologies commonly applied in plasma and derivatives have the capacity to mitigate the risk of ZIKV transmission by transfusion.

Keywords: ZIKV; low pH; methylene blue; pasteurization; solvent/detergent.