Vaccine Quality Is a Key Factor to Determine Thermal Stability of Commercial Newcastle Disease (ND)Vaccines

Vaccination against Newcastle disease (ND), a devastating viral of chickens, is often hampered by thermal inactivation the live vaccines, in particular tropical and hot climate conditions. In past, “thermostable” vaccine strains (I-2) were proposed to overcome this problem but previous comparative studies did not include formulation-specific factors commercial vaccines. current study, we aimed verify superior stability commercially formulated I-2 comparing six available ND Subjected 37 °C as lyophilized preparations, two vaccines containing more sensitive than third or compared three other based on different strains. However, reconstitution proved have comparable tenacity. Interestingly, all still retained sufficient virus dose for protection (106 EID50) after 1 day at °C. These results suggest that there are specific influence beyond strain-specific characteristics. Exposing elevated temperatures 51 61 demonstrated dissolved including occurred within 2 4 h. The revealed important differences among emphasize importance quality certain preparation rather strain it contains. data highlight regardless used preparation, appropriate cold chain mandatory keeping efficiency climates.