Antibody prophylaxis against Tembusu virus-associated disease.

Earlier studies have shown that Tembusu virus (TMUV) can elicit high levels of neutralizing antibodies, but the ability of antibodies to protect against TMUV-associated disease and to inhibit replication of TMUV in vivo remains to be investigated. Here, we tested the prophylactic efficacy of TMUV immune serum directly using a 2-day-old Pekin duck model. Passive administration of the immune serum prior to challenge protected ducklings against morbidity and mortality, substantially reduced TMUV-caused tissue injury, and significantly decreased TMUV levels in the periphery and central nervous system. These findings demonstrate that antibodies play a dominant protective role in controlling TMUV-associated disease.