Wein Yossi, Loeb Virginie, Asmare Aderajew, Tal Saar, Finger Avner, Friedman Aharon
Department of Animal Sciences, R.H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 7610001, Israel.
Phibro Animal Health Corporation, P.O. Box 489, Beit Shemesh 99100, Israel.
Vaccines (Basel). 2023 Aug 2;11(8):1316. doi: 10.3390/vaccines11081316.
is an attenuated infectious bursal disease virus vaccine. Previously, we observed a temporal delay of vaccine virus replication in the bursae of chicks due to maternally derived antibodies (MDAs). The mechanism that allowed its survival despite MDA neutralization remained unclear. We hypothesized that after vaccination at 1 day of age (DOA), the virus penetrates and resides in local macrophages that are then distributed to lymphoid organs. Furthermore, 's ability to survive within macrophages ensures its survival during effective MDA protection. PCR analysis of lymphoid organs from chicks with MDA, vaccinated on 1 DOA, demonstrated that the virus was identified at low levels solely in the spleen pre-14 days of age. Fourteen days after vaccination, the virus was identified using PCR in the bursa, with viral levels increasing with time. The possible delay in viral colonization of the bursa was attributed to the presence of anti- capsid VP2 maternal IgA and IgY in the bursa interstitium. These indicate that during the period of high MDA levels, a small but viable viral reservoir was maintained in the spleen, which might have served to colonize the bursa after MDA levels declined. Thereafter, individual immunization of chicks against Gumboro disease was achieved.
是一种减毒传染性法氏囊病病毒疫苗。此前，我们观察到由于母源抗体（MDA），疫苗病毒在雏鸡法氏囊中复制存在时间延迟。尽管MDA具有中和作用，但其存活的机制仍不清楚。我们推测在1日龄（DOA）接种疫苗后，病毒穿透并驻留在局部巨噬细胞中，然后这些巨噬细胞被分布到淋巴器官。此外，其在巨噬细胞内存活的能力确保了它在有效的MDA保护期间存活。对1日龄接种疫苗且带有MDA的雏鸡的淋巴器官进行PCR分析表明，仅在14日龄前的脾脏中检测到低水平的该病毒。接种疫苗14天后，在法氏囊中通过PCR检测到该病毒，且病毒水平随时间增加。法氏囊病毒定植可能的延迟归因于法氏囊间质中存在抗衣壳VP2母源IgA和IgY。这些表明在MDA水平较高的时期，脾脏中维持着一个小但存活的该病毒库，这可能在MDA水平下降后用于法氏囊的定植。此后，实现了雏鸡针对传染性腔上囊病的个体免疫。
