Đánh giá hiệu lực của vacxin amervac PRRS đối với chủng virus PRRS gây bệnh động lực cao ở việt nam

KHOA HOC KY THUAT T H O Y TAP XXI SO - 2014 i0Sl)iln cifu fefipa toe DANH GlA HIEU llfC CUA UACXIN AMERVAC PRRS 001 VOll CHUNG VIRUS PRRS GAY RENH DONG llfC CAO A VIET NAM To Long Thanh', Nguyen Hoang Bang', Tdng HS-u Hien', Bach Qudc Thdng', Daniel Torrent^ TOM TAT Dung vacxin AMERVAC PRRS khdo nghiem tren Ion k6t qua cho thiy nhu sau: Vacxin nhu^c doc AMERVAC PRRS hSng Laboratorios HIPRA, S.A san xuit dam bao an toan su dung. Vims vacxin khong truyen ngang tir 16 thi nghiem sang 16 doi chung va c6 tac dung kich thich sinh dap ung mien dich Ion bi nhiem virus cuong doc va cho dap iing mien dich se manh hon. Dap ung mien dich vacxin tao co tac dung lam giam muc dp tram trpng ciia benh cong voi chung virus PRRS cuong doc ciia Viet Nam thong qua kiem tra benh tich dai the va vi the tren cac ca quan npi tang, dac biet la a phoi. Lo diing vacxin ciing tang trpng hon so voi 16 khong dimg vacxin cong cudng dpe. Dap ung mien dich co dupc nha vacxin da loai bo hoan toan virus ca the Ipn v^o khoang 2-3 tuan sau bi nhiem. Tir khoa: Lan, PRRS, vacxin PRRS, khao nghiem, cong cuong dpe Evaluation of efficiency of Amervac PRRS vaccine for the High virulent, pathologenic virus strain in Viet Nam To Long Thanh, Nguyen Hoang Dang, Tong Huu Hien, Bach Quoc Thang, Daniel Torrents SUMI\/IARY Live AMERVAC PRRS vaccine produced by HIPRA Laboratory, SA (Spain) was used for testing on pigs raising in Viet Nam The tested result indicated that this vaccine was safe in use. Vaccine virus did not transmit horizontally from experimental pigs to control pigs and had the effect in inducing immune response at higher level when the pig was Infected with challenge virus. Immune response induced by vaccine had the effect in reducing the serious level of disease when challenge with virus strains of Viet Nam. This result showed clearly when testing the gross and histobiological lesions in internal organs (particularly is lung). The vaccinated pigs also increased higher body weight compared to the control pigs when applying challenge test. Immune response induced by vaccinating AMERVAC PRRS vaccine had removed the entire of virus In pigs in 2-3 weeks after pigs were infected with PRRS. Key words: Pig, PRRS, PRRS vaccine, Testing, Challenge test ' Trung tam chan doan thii y Trung uong ' Cong ly thii y xanh ^ Cong ty Hipra S.A, Amer Tay Ban Nha KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 I. DAT VAN DE Hpi chung roi loan sinh san va ho hap ciia Ign (PRRS) th8 doc luc cao virus PRRS (PRRSV) thuoc genotype II gay ra. The benh xuat hien tai Viet Nam nam 2007 va da gay nen nhung t6n thSt kinh t6 nang ne cho nhirng nguai chan nuoi lan nhiing nam sau do. Ve lich sir, PRRSV genotype xuat hien lan dSu tien tai Ha Lan nam 1986, gay nen PRRS the kinh di£n hay gpi la PRRS the doc luc thap da tham nhap vao Viet Nam tir cuoi nam 1996 dau nam 1997. Nhirng nam sau do, mpt s6 loai vacxin, c6 vacxin AMERVAC PRRS da dupc dang ky sir dung tai Viet Nam. Vacxin AMERVAC PRRS la vacxin genotype I da duac su dung ke tir dang ky tu nam 2005 cho den nay. Viec sir dung rpng rai vacxin AMERVAC PRRS (genotype I) d§ phong ch6ng PRRS thd doc luc cao (genotype II) tai cac dia phuang doi hoi viec danh gia kha nang bao hp ciia loai vacxin vai chung PRRSV the doc luc cao dang liru hanh tai Viet Nam. Day cung chinh la muc dich cua bai bao nay. IL NGUYEN LIEU VA PHU'CTNG PHAP NGHIEN ClTU 2.1. Nguyfin v3t lieu - Dpng vat thi nghiem: Chpn 16 lan tuan tuoi, khoe manh va am tinh vdi virus PRRS, khong hem bdt ky mot loai vacxin phong PRRS nao. Lan duac nuoi va tien hanh thuc nghiem tai Trung tam chan doan thii y TW. - Vacxin nhupc doc AMERVAC PRRS hang Laboratorios HIPRA, S.A san xuat, dung cho lan tuan tuoi tro len. Virus cuong doc gom chung: Chiing virus PRRS so 21 cong ty HIPRA cung cap CO ngu6n goe tir Viet Nam nam 2008 va chiing vims PRRS ky hieu VN07196 cua Trung tam chan doan thii y TW. - Kit ELlSAphat hien khang thi PRRS - Kit chiet tach Qiagen RNeasy, kit nhan gen Invitrogen SSIII One-step qRT-PCR system (Cat 11732-020). - Cac hoa chat va nguyen lieu can thiet khac. 2.2. Phucmg ph^p nghien ciru - Bo tri thi nghiem: % a i livti ^ a p l m o n g i>li:'ip t h i ii)?;lii I • • " • " " — E"::;"!" il . . n . , ™ « „ . F^HSil \ — ™.™i.™.D*,.«CM. ™*_^_^_ ,M '"IT"" '*i-^':^^"^r-'-™ KHOA HQC K? THUAT THO Y TAP XXI S6 - 2014 Theo d5i Ipn sau tidm vacxin d^ danh gia tinh an toan, bieu hi?n iam sang \k bi^n ddi than nhi?t tir diij 32 dgn 46. Can Ipn, theo d5i trpng lupng vao cac thir 0, 32, 39, 36 va 55. LSy mau vao cac thu 29,35, 39,42,46 va 55 d6 xet nghi?m ham lupng virus huy6t. Xet nghi?m khang th6 khang virus PRRS vao cac thu 0, 29 va 55. M6 kham kigm tra benh tich, cham diem phoi tit ca Ipn vao thijr 55. cuong dpe voi cdc chi tieu khac bao g6m: Bilu hien lam sang, tang than nhiet, benh dch dai the, vi the a ph6i, tinh trang nhilm virus mau va kiem tra dap irng mien dich bdng phucmg phdp huylt hoc. 2.3. Cdc phinmg phdp xit nghl|in Theo doi mot tuan sau tiem vacxin Ipn khdng thay co bat ky cac phan img bdt thudng nhu: met moi, chdn hoac bo an, tang than nhiet va cac dau hieu benh Iy. Nhu vay, cho thdy vacxin AMERVAC PRRS la an toan. - Diing phuang phdp ELISA va IPMA d6 kiim tra khang thS. - Dimg phuang phap Real-time RT-PCR d8 kiem tra virus. - Dung phuang phap m6 kham va lam tiSu bdn vi thi de kiem tra b8nh tich dai th8 va vi thi. - Phuang phdp ddnh gia an toan ciia vacxin: Theo doi mpt tudn sau tiem vacxin, nlu khong CO phdn irng bat thuong nhu: mSt moi, chdn ho^c b6 dn, tdng than nhi?t vd cdc dau hieu b?nh 1^ khdc Id an toan. - Phuang phdp ddnh gid hi$u luc ciia vacxin: Hi^n tai, Vi?t Nam chua c6 chting virus PRRS c6 khd ndng gay chit 100% Ipn man cam nen vi^c ddnh gid hi?u qua cua vacxin PRRS can phai kit hpp giiJa chi d6u bao hp sau cong III. K E T Q U A VA T H A O LUAN 3.1 Ket qua theo doi an to£kn sau tiSm vacxin 3.2 Ket qud theo doi sau cong c u ^ g d$c 3.2.1. Bieu hien lam sang va thdn nhi^t sau cong cir&ng dpe Lpn sau cong bang loai virus PRRS vao 32. Tir 33 d6n 46 theo doi nhiet d6 vd cac bieu hien Iam sang va cham diem. K6t qud theo doi Iam sang dupe the hien trenbiludo lava lb. Nhan xet ve lam sang: * Cong c u ^ g d$c v6i virus PRRS 21 -,c —• ^ 2,0 J 1.5 -^V)t1 -•-DC-1 '•'' Q 0.5 / / / J y* X \ ^^*^ ^ *\ ,y^^^ \ \ "\'" ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ .^ ^ .^ Bieu la. Bieu hi^n tam sdng cua Iqn dirpv cong virus PRRS 21 KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 - Sau nhilm virus PRRS 21, lpn 16 (VX-1) va 16 (DC-1) bit ddu co nhimg bilu hien ddu tien sau 1-2 ngay. Trieu chirag thudng thdy Id lpn giam nhanh nhen, an it hon miic binh thudng, lpn ddi chung an it han lpn tiem vacxin. - Trieu chung tien triln nhanh va nang han d nhung Ion ddi chiing. Tir 4-8 sau nhilm virus Id giai doan b?nh n$ng nhat. cham chap, it van ddng va gidm dn. Mdt s6 cd trieu chung thd nang nhpc hoac tim tdi d tai. Co lpn (s6 11) d Id ddi chung cd bieu hien benh nang han cac cdn lai id, the trang rat met mdi, thd ddc "kieu chd ngdi" vd co hien tupng tim tai. Ddi vdi nhung lpn Id vacxin, cac tri?u chung tren khdng bieu hien ro va thudng chi keo dai 1-2 ngdy, khdng lau nhu Ion ddi chumg. - Tir 8-10 sau cdng (ngay thu 40 ttd di) cac trieu chiing bSnh giam ddn, Ion nhanh nhen ban, an khde. Nhdm Ipn vacxin den ngdy thu 42 da khdng the hien trieu chiing. Nhom lpn ddi chumg phuc hdi cham hon 3-4 ngdy. Rieng Ion sd 11 thudc 16 ddi chumg bieu hien benh mdt nang va chet vdo ngdy thii 44 (ngdy 12 sau cdng). * Cong cudng doc vdi virus PRRS VN07196 2.0 c » £ 15 E 10 r^^~~~ / V 05 / — — • /, 00 .^ ^ fij" ^ t^ / \ , "\^ \ \ \ \^ V^^\ , \ \ 1^ ' ^^^ ^^^ ^^^ ^^^ ^^^ ^^^ ^^^ ^^"^ ^ Bieu lb. Bieu hi$n lam sang cua Ion dw^ cong virus PRRS VN07196 - Lan Id va sau cong virus PRRS -VN 07196 bat ddu cd bieu hien benh sau nhiem virus 3-4 ngay. Tien trien benh cd the quan sat dupc la hien tupng moi m8t, cham chap. Tuy nhien lupng cam tieu thu van khdng gidm, hoac chi giam khong dang ke. Lpn doi chiing co bieu hien benh nhanh ban vd nang ban so voi nhom vacxin. - Qud trinh benh keo dai khodng vai (tir thii 37 d6n ngdy thii 42) Id ndng nhat, vdi hien tupng Ion met moi, thd khd vd ludi van ddng. Miic an d nhimg ndy giam han so vdi trudc vd lpn tiem vacxin an nhieu hon 1pm ddi chiing. Ld cd Ipn ddi chiing (so 8) cd bieu hien b8nh nang horn nhung cdn lai cung Id, thudng nam bep mpt cho. Lpn ndy chit vao thii 43 (tiic la 11 sau bi gay nhilm bdng virus PRRS VN07196). - Lpn Id vacxin bdt ddu hit cac tri?u chiing vd phuc hdi sau khodng 10 ngdy nhilm virus. Lpn ddi chiing cd thdi gian phuc hdi cham hon. KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 Nhdn xet ve thdn nhiet: -vx-2 -DC-2 -^ "'• 4- -^ •^ - ^. [3-^ I?^ ftp-^ li^^ ^ .^ .^ .^ .^ ^ ^ . J ^ ^ ^ ; ^ ^ , ^ ^ Bieu dd 2a. Diin bien than nhiet cua lan du^ ^ / 41.0 r-^ O 40.5 ' 40.0 c S 39.5 1- 39.0 giy nhi$m virus PRRS 21 It J/> -.-VX-1 r^--y~^~^^^^ -.-BC-1 ^~~---4--;--,__--_^ ^^'^^— 38 ^^ -^^ /^ /^ 4> .^Q. .^Qp .^' .^o. . ^ . ^ . ^ ^^ ^^ ^^ ^^ >^ J> ^ti^ >*^ >* . ^ .^o. ^ .^Qi .^Q> ^ ^Qi ^Q, Bleu 2b. Dien biin thSn nhi$t ciia /pn {fut>v giy nhiem virus PRRS VN07196 Bieu 2a vd 2b d tr8n th6 hi8n dien bien thdn nhi?t cua lpn sau nhiem loai virus PRRS. - Than nhiet trung binh bat ddu tang hi ngdy thii 33 (virus PRRS 21) bic la sau cdng cudng dpe ngdy. - Lpn s6t cao nhdt vdo giai doan thii 35-41 vdi than nhi$t trung binh co liic len tdi tren 41''C, ddc biet la cdc Ion d Id ddi chumg. Tren bieu dd cho thdy virus PRRS 21 gay sdt vdi thdi gian nhanh hon (sau ngdy, than nhiet trung binh tren 40°C); nhien virus VN07196 lai gay sdt dai han (den thii 44). - Qud trinh sdt gidm ddn tir ngdy thii 41-42 vd lpn lai trd ve miic than nhiet binh thudng. Rieng lpn sd 11 (Id 2) va lpn sd (16 4) cd hien tupng giam than nhiet xudng dudi 38''C va chet. KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 3.2.2. Trang thdi virus huyit (Xem bdng 1) Bang 1. Mipc virus huyet tren Ion (tinh trung binh) L6 Ngay 29 Ngay 35 Ngay 39 Ngay 42 Ngiy 46 NgjiySS VX-1 40,00 29,61 27,15 29,98 34,99 37,72 BC-1 40,00 26,69 24,29 26,55 32,39 37,23 VX-2 40,00 27,95 26,93 28,76 33,16 36,63 DC-2 40,00 26,01 24,32 26,20 33,75 33,65 (Ghi chit: Cl la ngudng vong cUa phdn img Realtime RT-PCR, ddnh gia luong virus cao hay thdp, Cl cang thdp luang virus cdng nhieu va nguac lai. Thong thudng phdn iing RRTPCR co Ct < 35 la duong tinh Coi kit qud dm tinh virus huyet co gid tri Ct = 40) Bieu 3. Mux: virus huyet - Trudc cdng cudng doc (ngdy thir 29), khdng phdt hien thdy virus PRRS huylt tdt cd lpn d cac 16. - C6ng cudng dpe d thdi dilm ngdy thii 32. Sau dd lay mdu vao cdc ngdy thii 35, 39,42, 46 va 55 de kiem tra mire dp virus huylt. Kit qud the hien tren bang va bieu cho thay virus xudt hien huyet lpn dat cao nhdt vdo giai doan thu 35-42 (tiic la 3-10 sau gdy nhilm) va giam dan d nhung tiep theo. - Tai ciing thdi dilm, lupng virus huyet cr Ion thudc cdc Id ddi chiing cao han Ipn d cdc 16 vacxin tli 4-8 ldn (chenh lech 2-3 Ct). - Den ngdy thii 55 ket thiic thi nghi?m, vdn cdn lupng nhd virus phat hien dupc huyet Ign ddi chiing duac c6ng virus VN07196. Cac nhom khdc khdng cdn virus huyet thanh. KHOA HOC KY THUAT THU Y TAP XXI S - 2014 3.2.3. Ddp umg miSn djch (Xem bdng vd 3) Bang 2. Ket qua kiem tra hieu gia khang the blng phu'tyng phap ELISA Lo Virus CCD S6tai PRRS 21 PRRS VN 07196 Ngay Ngay 29 Ngay 55 S/P KQ S/P KQ S/P KQ 0,041943 Neg 2,27807 Pos 2,3246 Pos 0,335541 Neg 0,0241 Neg 2,09607 Pos 0,311258 Neg 3,20321 Pos 2,538574 Pos 13 0,280353 Neg 3,59626 Pos 2,11936 Pos 0,19426 Neg 0,0214 Neg 1,41048 Pos 10 0,328918 Neg Neg 1,918486 Pos 11 0,00662 Neg 0,03476 Neg 12 0,015453 Neg 0,00802 Neg 1,606987 Pos 0,07064 Neg 2,63636 Pos 2,010189 Pos LON C H £ T 0,00662 Neg 0,0187 Neg 1,416303 Pos 18 0,01987 Neg 2,29412 Pos 2,525473 Pos 19 0,011038 Neg 2,10695 Pos 1,570597 Pos 0,03532 Neg 0,03476 Neg 14 0,04636 Neg 0,0053 Neg 1,770015 Pos 15 0,02649 Neg 0,04278 Neg 1,390102 Pos 0,00662 Neg 0,05348 Neg 1,528384 Pos LON C H E T Bdng 3. Ket qua kiem tra hieu gia khang the bang phuxyng phap IPMA Lo Vims cong PRRS 21 PRI^S VN 07196 So tai NgayO Ngay 29 Ngay 55 Neg 640 1/1280 Neg Neg 1/640 Neg 1/2560 1/1280 13 Neg 1/5120 1/640 Neg Neg 1/320 10 Neg Neg 1/640 11 Neg Neg LON C H E T 12 Neg Neg 1/640 Neg 1/1280 1/640 Neg Neg 1/320 18 Neg >1/640 1/1280 19 Neg 1/640 1/320 Neg Neg LgN CH^T 14 Neg Neg 1/640 15 Neg Neg 1/320 16 Neg Neg 1/320 KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 Nhdn xet: - Trudc tiem vacxin vdo 0, tat cd 16 Ion ciia Id deu dm tinh vai khang the khang virus PRRS (ca phuang phdp xet nghiem ELISA va IPMA) - Sau tiem vacxin Amervac cho Id dupc 29 ngdy thay rang cd 6/8 cd khang thi khdng virus PRRS. Ty le S/P trung binh vd hieu gia khang the trung binh 16 cao hon 16 3. Khdng phdt hien dupc khang the khang virus PRRS tren Ion cua Id khdng tiem vacxin { am tinh). Dieu chung td vacxin khong truyln ngang tir 16 thi nghiem sang 16 doi chirng. - Sau c6ng cudng doc 23 (tire la thir 55) cd 16 deu cd khang the d 14 lpn sdng sdt (mdi 16 d6i chiing chet 1/4 lpn). Ty 1^ S/P trung binh vd hi$u gia khang the trung binh d Id tiem vacxin cao hon Id ddi chiing Co the nhdn thdy su chuyen biSn ddp iing miln dich tao khdng the thdng qua cac ket qua ciia phuang phdp ELISA va IPMA sau tiem vacxin va sau cdng cudng ddc. Dilu chung to vi|c sir dung vacxin da kich thich hinh thdnh dap ung miln dich ddc hi§u. Ddp iing miln dich dupc thiic day va ham lupng khdng the tdng cao lpn dupc tiem vacxin nhd phdn iing hdi lic sau lpn dupc cdng cudng doc. 3.2.4, Tdng (Xem bdng 4). Bang 4. Theo doi lyvng trung binh cua \tyt\ Id thi nghiem L6 Ttieo doi trijng lu'o'ng TB (Itg) NgayO Ngay 32 (CCB) Ngay 39 Ngay 46 Ngiy 55 Lo (VX) 6,1 14,4 16,5 19,2 22,8 Lo (DC) 5,9 14,3 14,8 16,1 19,0 L6 (VX) 6,3 14,5 16,9 19,8 23,5 Lo (DC) 6,2 14,6 15,2 16,6 19,6 - O giai doan sau tiem vacxin (ngay den ngdy 32), miic tang trpng Ipm la tuong duong giira cdc 16. Dieu cho thdy vacxin kh6ng dnh hudng tdi qua trinh tang trpng d nhiing lpn dupc tiem. - Sau cdng cudng ddc (ngay thii 32 trd dl), miic dp tang trpng giam hon so vdi tnrdc . Sau 23 cdng virus PRRS 21, Id tang 8,4 kg, 16 tang 4,7 kg, nhu vay 16 dung vacxin tang trpng cao ban Id ddi chimg la 3,7 kg. - Sau 23 ngdy cong virus PRRS VN 07196 16 tang kg, cdn Id tang 4,9 kg, nhu v?y 16 dung vacxin tang trpng cao hon 16 d6i chimg la 4,1 kg. L6 dung vacxin AMERVAC PRRS tSng tdt h 2+ 3+ 2+ Diem tnjng binh io = 2,50 Diem trung binii io = 2,50 Lo - vacxin Virus VN07196 Lo - d6i clii>ng S61 So So 18 So 19 S6 S6l4 S6l5 S6l6 2+ 2+ 2+ 1+ 2+ 1+ 3+ 2+ Diem trung binii io = 1,75 Nhdn xet benh tich dai the: Sau cong cudng doc, Ion ciia tdt cd cdc 16 thi nghiem va ddi chiing deu cd cac benh tich d?i the viem d phdi. B6nh tich chu yeu Id hien tupng viem ke, xuat huyet va thung, xay d tat ca cac thiiy ph6i. Mpt sd Ion ddi Diem trung binh 16 = 2,00 chung cd hien tupng teo thiiy phdi (nhdt Id thiiy tim). Cac hach phe qudn bj viem, sung vd xudt huyet, xudt hien ca d Id vacxin va Id ddi chiing. Benh tich dai th€ o phdi ciia Ign Id tiem vacxin cd bieu hien viem nhg hon so v ^ Ign cua Id doi chirng. Ld - Doi chLPng cong PRRS 21 PhSl viem ke, xuit huyil Hach phe quan sung, xuit huySt Lo -Vacxin cong PRRS 21 Phdi xuk huyet nh? Hach mitig treo ruQt binh thucmg KHOA HOC KY THUAT THO Y TAP XXI SO - 2014 L6 - Ooi chirng cong VN 07196 Phoi viem ke, xuat huyet Hach phe quan sung, phii Lo - Vacxin cong VN 07196 I"* Qj Hach mang treo rudt binh thuung Nhdn xet benh tich vi the: - Benh tich vi the cac 16 doi chiing: Ld (c6ng vims PRRS 21) vd Id (cdng vims PRRS VN 07196) cd benh tich nang phii ne mang phdi, vdch ngan gian rpng, Idng phe quan chiia dich ri viem va tl bdo viem, hinh huyet khdi, viem mach tang sinh, vach phi nang day tang sinh te bao phi nang loai 2. Lo cd bieu hien benh tich ndng ne hem 16 4. - Benh tich vi the cdc 16 vx: L6 (cdng virus PRRS 21) va 16 (cdng virus PRRS - VN 07196) cdu tnic phdi cac diiiy vdn cdn nguyen ven, mang phdi, vach ngan ro rdng, vdch phe nang mong, cau tnic tiii rd rang. Nhu vdy, cdng virus cudng doc PRRS, 16 dupc tiem phong vacxin Amervac cd tac dung bao ve phdi va cac ca quan khdc nhu lach, h?ch, amidan khdng bi virus tdn cdng, Id khong tiem phdng, phoi vd cdc ca quan ndi tang deu co biln ddi benh tich vi thi ndng su xdm nhap cua virus PRRS. KHOA HOC KY THUAT THU Y TAP XXI SO - 2014 Mpt so hinh anh benh tich vi thg; Lo B/C (cdng virus PRRS 21) : ~ ' - i . ^ V[...]... tang, dac biet la ph6i cua lpn sau khi bi nhiem virus cudng doc PRRS - Lo diing vacxin AMERVAC PRRS tang trpng ban so vdi Id khdng dimg vacxin khi cdng virus PRRS cuong ddc - Dap ling mien dich co dupc nhd vacxin da loai bd hoan todn virus trong ca the Ipn vao khodng 2-3 tudn sau khi bi nhilm Lpn dugc tiem vacxin, khi bi nhiem virut cudng doc se khdng dao thai virus cudng ddc ra mdi tnidng xung quanh TAI... luan nhu sau : O - Vacxin nhuac doc AMERVAC PRRS do hang Laboratorios HIPRA, S.A san xuat dam bao an todn khi sir dung tiem phdng cho lan - Virus vacxin khdng truyen ngang tir 16 thi nghiem sang Id ddi chimg va cd tdc dung kich thich sinh dap ung mien dich khi Ian bi nhiem virus cudng ddc (hodc c6ng cudng doc) dap ung mien dich se manh ban - Dap ling mien dich do vacxin tao ra cd tac dung 1dm giam miic... virus PRRS - V N 07196) ;^3^%;:^^?»s;ra.ipi^%f Ph6i: Vdch phi nang day, mach quin hinh thdnh huyet khoi H$ch khi phi quan: Nang lympho gian rQng, tang sinh dai thijc bao va co ti bao lympho hoat dgng KHOA HOC KT THUAT THI? Y TAP XXI S6 1 - 2014 L6 3 VX (cong virus PRRS -VN 07196) Phoi: Binh thuxyng IV K E T L U A N Dua vao cac ket qua thuc nghiem neu tren, C the riit ra cdc ket luan nhu sau : O - Vacxin. .. Y TAP XXI SO 1 - 2014 Mpt so hinh anh benh tich vi thg; Lo 2 B/C (cdng virus PRRS 21) : ~ ' - i 5 ^ V . Viet Nam tir cuoi nam 1996 dau nam 1997. Nhirng nam sau do, mpt s6 loai vacxin, trong do c6 vacxin AMERVAC PRRS da dupc dang ky sir dung tai Viet Nam. Vacxin AMERVAC PRRS la vacxin genotype. cudng doc PRRS. - Lo diing vacxin AMERVAC PRRS tang trpng ban so vdi Id khdng dimg vacxin khi cdng virus PRRS cuong ddc. - Dap ling mien dich co dupc nhd vacxin da loai bd hoan todn virus. nhu v?y 16 dung vacxin tang trpng cao hon 16 d6i chimg la 4,1 kg. L6 dung vacxin AMERVAC PRRS tSng trong tdt h<ra so vdi 15 khong dung vacxin khi cong virus PRRS cu-dng dOc.