Preparation of a Thermostable Bovine Ephemeral Fever Virus Vaccine Inactivated on the Time of Use

Abstract

he herein study was devoted to overcome the obstacles dealing with the utilization of the live attenuated Bovine Ephemeral Fever (BEF) vaccine viz, the cold chain and the undesirable post-vaccinal reaction. Methylglucoside-sucrose (MS) was proved to be an excellent stabilizer for BEF thermostable vaccine. The permissible titer of the lyophilized MS-BEF thermostable vaccine was achieved even after 6 months at 25°C, 3 months at 37°C and 20 days at 45°C. The study revealed that freeze-dried MS-BEF thermostable vaccine was reconstituted with saponine (0.2µg/dose) as inactivator just at the time of inoculation. Such investigations were carried out on 4 groups of calves each was consisted of three animals. The first group animals were inoculated with the MS-BEF thermostable vaccine kept at 25°C for 6 months. The second groups were inoculated with the forementioned vaccine kept at 37°C for 3 months. The third group animals were vaccinated with BEF vaccine kept at 45 for 20 days. (The vaccine titer was 10 5.5 TCID50/ml in the three above mentioned groups), whereas the fourth group was kept as nonvaccinated normal controls. The three animal groups received booster dose at two weeks post-first vaccination. It has been deduced that such vaccine effectively induced high mean BEF neutralizing antibody titers post-boostering vaccination and protected cattle for one year. Thus, MS stabilizer was recommended for preparation of thermostable live BEF vaccine inactivated at the spot with saponine.

Thermostable Vaccines in Veterinary Medicine: State of the Art and Opportunities to Be Seized

“…If we look back at recent and past history, our literature search highlights that the freeze-drying process is a valuable method to obtain vaccine thermostability [47,49,50,52,[65][66][67]70,74,76,79,85]. An improved freeze-drying process was used to develop a thermostable Rinderpest vaccine (Thermovax), which was an essential tool for eradicating the disease in remote pastoral areas [127].…”

“…An improved freeze-drying process was used to develop a thermostable Rinderpest vaccine (Thermovax), which was an essential tool for eradicating the disease in remote pastoral areas [127]. In this study we identified dried formulations (freeze-or foam-dried) for vaccines against NDV (e.g., [52]), bovine ephemeral fever virus (BEFV) [74], classical swine fever virus (CSFV) [85], rabies [77], and PPR [47], highlighting that the drying process is a useful technique to improve the thermostability of vaccines against diverse diseases in several species. However, it is worth mentioning that the drying process alone is not able to confer a long-term stability in the formulations.…”

“…Out of the 43 articles retrieved with the broad literature search, 13 studies (these include only the studies that explicitly state that the freeze-drying process was used for the vaccine development) implemented a lyophilization (freeze-drying process) to obtain thermostability [47,49,50,52,[65][66][67]70,74,76,79,85]. An alternative drying process was applied by Lv et al [64] and Smith et al [77], who used the vaporization method (foam-drying) to preserve the live attenuated vaccines against the porcine reproductive and respiratory syndrome virus (PRRSV) and the rabies virus (RABV), respectively, while Dulal et al [51] successfully used the sugar-membrane technology to thermostabilize an adenovirus-vectored vaccine against the Rift Valley fever virus.…”