Roy, ParimalPadmanaban, V.D.TANUVAS2016-08-122016-08-121991-03http://krishikosh.egranth.ac.in/handle/1/72385Three hundred day old chicks were taken for experiment and divided into four groups. One group was kept as control and other three were subjected to different vaccination regimen. Each group was subjected to challenge with virulent virus (100 CMD 50 dose). Antibody levels before challenge and upto 3 weeks of challenge were assayed by SNT, HI and ELISA. Protection offered against different vaccination were compared and discussed. Vaccination of birds with lentogenic vaccine twice and mesogenic vaccine once was considered the best.enArticle