Fig. 3. Ad26.M.Env vaccination prevents viral replication in blood and dissemination of ZIKV to tissues in pregnant dams.

Pregnant Ad26.M.Env vaccinated (n = 9) and non- vaccinated (n = 5) macaques were challenged with 1×10⁶ vp of ZIKV at 6 weeks following conception and sera was monitored longitudinally for 100 days following challenge. ZIKV log10 copies per mL of sera from (a) Ad26.M.Env vaccinated dams and (b) non-vaccinated dams were determined by qRT-PCR and depicted as log10 ZIKV copies/mL sera at days 0, 7, 14, 28, 42, 56, 70, 84, and 98. The limit of detection of this assay was 100 copies/mL sera (2Log10). a Individual animals of group 1 (Ad26.M.Env immunized) are color coded to represent number of weeks between immunization and challenge; green (10wk); purple (12 weeks); blue (14 weeks); gray (18 weeks); red (22 weeks); brown (30 weeks). Lymphoid and reproductive tissues were collected from dams at time of Cesarian section (C-section). C-sections were performed 10–14 days prior to estimated full-term delivery dates (~21–23 weeks pregnancy) at approximately 16 weeks following ZIKV challenge. Viral RNA was determined by RT-PCR for (c) Ad26.M.Env vaccinated and (d) non-vaccinated dams on tissues collected at necropsy. AxLN axillary lymph node, IngLN inguinal LN.