- Th^nh phan hoa hgc va tmh khong thuan nhat: Chi kich thuoc vd tinh la chua du dl xac dinh
1.4.2.7.Ve virutRota giam dgc lye đng Sahin
ị4.ịyirut sm
1.4.2.7.Ve virutRota giam dgc lye đng Sahin
Chimg Sabin typ 1 bit ngudn tir virut Rota hoang dai typ I va dugc cay chuyen nhieu lan. Cung nhu chimg dgc luc, chimg Sabm cd 7441 nucleotit. Trong doan tir nucleotit 1-743 chi c6 2 nucleotit khac bift giua chiing đc luc vd chung giam đc luc do Id vi tri 480G vd 525 U nhung chi cd vi tri 480 lien quan din dgc luc ciia virut. Doan gen tir nucleotit 1813-3421 ciing dnh hudng den dgc lye cua virut, trong vimg do chi cd vi tri 2438A, 2471G vd 2795A cua đng Sabin khac virut dgc lyẹ Chimg san xuit vdcxin Bai Uet typ 1 t ^ nude ta Id chung dugc cung cap tir Vifn Nghien
ciiu B?ii lift Nhat Bdn cd ngudn gdc tii chung Sabm cua Td chiic Y te Thd gidi cd ten la WHO-IS-
90C dugc ciy chuyin 02 lan (SƠ2) vd cd hifu gid Id lỐ^CCID/50/ml.
Chung Sabin typ 2 bdt ngudn tir virut Rota đc luc typ 2, phdt trien tai dudng mgt ngudi, cd khd ndng kich thich co the tao mien dich nhung khdng gay liet. Virut Rota dgc luc qua nhieu Idn ciy truyin kit hgp vdi phuong phdp tinh che, chgn Igc đm hoai tir d ndng do 0,22%i NaHC03. Sabin đ tao chimg vurut Rota P2/P712, lOab, chiing ndy dugc Sabin thii so bg tren tinh tinh vd dng nh$n ra rdng chung virut Rota ndy cd m^t sd tinh ndng buy tl bao thin kmh tiiy va mgt sd thi khdng, Sabin đ nudi ciy phan cua tinh tinh trdn tl bdo tuy sdng vd cho ket qua dm tinh, sau đ dng phdn tich vd chgn đm hoai td tao chimg P712,ch,2ab 1dm chiing sdn xuit vdcxin vd dugc ggi la chiing Sabin dl sdn xuit vdcxin Bai lift gidm dgc luc. Chiing sdn xuit vdcxin Bai lift typ 2 ciia Vift nam Id chiing dugc cung cip tir Vifn Nghien ciiu Bai lift cua Nhat Bdn cd ngudn gdc tir chimg Sabm(SO) qua 02 lin ciy tiiiyln chgn lgc(S0+2) vd cd hieu gid Id 10*''°CCID/50 ggi Id chimg HS- 90Ạ Cling nhu virut dgc lye, virut gidm đc lye typ 2 cd phdn tu ARN bao gom 7439 nucleotit chi cd vj tri 481A (481G Id virut đc lye) vd 2908A khac virut đc lye va quyet dinh tinh an todn cua vdcxin.
Chimg Sabin typ 3 Id chung bdt ngudn tu virut đc luc typ 3(P3/leon/37), bang phuong piidp t^o đm hô tu qua nhilu lin ciy truyin tao chiing Leon 12ab. Chi cd đm hoai tir ciia virut Leon 12ab khdng tao ra hft tren khi khi tiem vao tuy sdng vdi lidu viruts Idn nhdt dugc chgn 1dm chiing sdn xuit vdcxin. Sau đ virut Leon 12ab dugc thu tren tinh tinh vd cho thay virut dao thdi ra khdng tdng đc lye thin kinh, thii tren tre vhut đo thdi qua phan cd tinh an todn caọ Virut Leon 12ab dugc T 6 chOrc Y tl Thi gidi ggi la chiing Sabin gdc typ 3 (SO). Chiing Sabin san xuit vdcxm B^ Uft t ^ 3 t^i Vift Nam Id chiing IIIS-79A dugc cung cip tir Vien Nghien cuu Bai liet cua Nhdt
bdn cd nguon gdc tir chiii^ Sabin (SO), qua 3 lin cay truyen vd 2 lan chgn Igc đm hoai tii tao chung IIIS-79ĂSƠ3+2). Cung nhu vmit đc luc, virut gidm đc luc phan tii ARN cd 7441 nucleotit chi cd vi tri 472 (472U Id viruts gidm đc lye va 472C la virut đc luc) va vi tri 2034 (2034U giam dgc lye va 2034 C Id virut dgc luc). Hai vi tri nay hen quan den sy an todn ciia vdcxin.