I faced many cases regarding outbreak of LPAI, in cox'sbazar region of Bangladesh, morbidity, mortality rate, some flock recovered, some flock re-infected few days(varies) interval,even month, some farmers confused with ND, even we the veterinarian also. I think it is unpredictable. Any time the disease might be very very harmful for public health & also in the industry. In my area, may be the whole country, individual farmer made decision wonself, they try to prevent the disease by using vaccination but results varies from case to case. As the mortality rate is low, nobody did concentrate their mind towards the proper solution.I knew there are many highly qualified consultant in this forum. I want to know which way is better for preventing the disease, either vaccination or improving Bio-security level ?