Release of Newcastle disease virus vaccine from chitosan microspheres in vitro and in vivo

Newcastle disease vaccine (NDV)-loaded chitosan microspheres (NDV-CM) were prepared. Stimulatory effects of these NDV-CM on antibody response compared to free NDV were examined in vitro and in vivo. In vitro stimulation of macrophages with virus vaccine resulted in higher number of cells compared to saline-treated control. Both NDV and NDV-CM induced secretion of interleukin-1 (IL-1) in dose dependent manner and the secretion of IL-1 by NDV-CM was delayed compared to free NDV. Irrespective of vaccine formulation, NDV subunit antigen was not effective in preventing mortality of the birds after challenge. However, CM loaded with NDV made of whole viron had antibody responses and protection similar to those shown by ND-K, a commercial inactivated oil-emulsion vaccine.