| Summary |
In order to iinxove the gesent method of inspection oft- infectious honchitis (IS) vaccines, three stains of infectious h-onchitis virus (ISV) (M41, Cc46, H120) were selectel and jxoprgatl in the enhyo to obtain thhe optimum time for ruoduction of higher hemagglutinatiog (HA) antigen. As a result incubotion of 1 0-day-old stificpathogen-free (SPF) ernhyonati eggs for 32-4 8 hours at 37? revealeri the virus titer could reach the level higher than 7.5 (Log 10 EID5&ml).
The above allantoic fluid was ooncentrated 1(0-fold by centrifugation. Virus pellets wer resuspended in HEPES-buffered saline (pH 6,4) containing 2 unit of phosplipaseCfrnl. Followingthetreatment, onlyoneoutofthreestrains of ISV (M4l)showerlo (Log2) HA titer. While there exisal HA titer great than 6 (Log2) using hte peparsi antigen in the v&xine-imrnunizd chickens, the neutralizing (Ni) antibody of sera still revealed higher index than 2.0 (Log 10). A significant relation was ohierv&1 ketween both resulls obtained from HA and NT method, Aftr the treatment of formalin, hte peparerl hernagglutination-inhibition (HI) antigen of ISV can store at 4? for 48 weeks stabk and still maintains it titer.
The SPF chickens were vaccinated with three strains ofhveattenaal ISV (H120, ON, Mas. 7), and blealed at 0,1, Z 4,8, 12 16 week. The levelof antibody was detec1by HI t and NT method. It showed the great HI liter at 4,8, weelc and these results are in agreement with & increasing curve of NT antibody. This demonstrates that HI test can apply to evaluate & efficacy of ISV vaccines.
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