Aerosol vaccination against Newcastle disease: the influence of vaccine diluent

Spray drying of an attenuated live Newcastle disease vaccine virus intended for respiratory mass vaccination of poultry

“…These particles are well suited for primary respiratory vaccination of poultry where deposition in the lower airways should be avoided to prevent post-vaccination reactions in the more vulnerable lungs [3][4][5]. To obtain this, vaccination of 1-day-old chickens should be performed with particles larger than 20 m, as determined in a previous study [37].…”

“…The pure components mannitol and trehalose had a density of 1.42 and 1.52 g/cm 3 , respectively. The addition of PVP or BSA to trehalose lowered the density to 1.45 and 1.47 g/cm 3 , respectively, and the additive effect of PVP and BSA resulted in the lowest density for the trehalose-PVP-BSA formulation (1.40 g/cm 3 ).…”

“…A first problem is the broad droplet size distribution generated by the nebulizers currently used for liquid spray and aerosol vaccination: the presence of small, inhalable droplets in a coarse spray for primary vaccination often results in post-vaccination reactions [3][4][5] and a large fraction of non-inhalable droplets generated by fine aerosol nebulizers (e.g., 10-1000 m [6]) reduces the efficiency of secondary vaccinations. Furthermore, the efficiency of vaccines administered by spray or aerosol might be jeopardized due to the use of tap water for reconstitution (often containing virucidal agents, such as chlorines) [7], by large shear forces which are applied to the liquid in order to transform it into droplets [8] and most importantly, due to inactivation of the vaccine virus by evaporation of droplets after generation [3,5,9].…”

Immunogenicity and Safety of La Sota Strain of Newcastle Disease Virus Administered to Newly Hatched Chicks by Nebulization

“…Since the nebulizer is constructed with a closed chamber, the size of particle produced remains constant in a high humidity atmosphere and the particles do not desiccate as is the case with all other aerosol devices Allan 1973, 1976). Therefore, the efficacy of nebulization can be further explained by the uniform particle size and the use of distilled water as a vaccine diluent (Gough and Allan 1973). The presence of relatively high (Table 2) levels of maternal antibodies in chickens of light hybrids did not influence the specific response to the given vaccine.…”

“…Efficacy of aerosol vaccination depends mainly on the size of droplets and the patterns of the device used for aerosol generation (Villegas and Kleven 1976). Aerosol droplets of ND B1 vaccine diluted in distilled water were more immunogenic compared to droplets derived from vaccine diluents containing tap water or gelatine (Gough and Allan 1973).…”