Multiplicity of infection and incubation period for fixed rabies virus strains propagation on BHK-21 and Vero cell lines

Abstract

Introduction:Rabies is a viral zoonotic disease under the genus Lyssavirus, family Rhabdoviridae which can affect all warm-blooded mammals including humans. The disease is 100% fatal if post exposure prophylaxis is not in place with effective vaccine timely. Production of quality cell culture vaccine is required for effective control and prevention of the disease. To produce high quality and effective vaccine, setting viral multiplicity of infection and incubation period at a pilot step is required.

Objective: To determining effective multiplicity of infection and incubation period for fixed rabies virus strains propagation on Baby Hamister Kidney-21 and Vero cell lines.

Materials and Methods:Vero and Baby Hamister Kidney-21 cell lines were infected with Eveninyl rokipinik avelset and Pastuer virus fixed rabies virus strains at 0.1, 0.01 and 0.001 tissue culture infectivity dose per cell and incubated for 48, 72 and 96 hours at 37 ⁰C. Viral cultures were harvested and determined for its titer and compared across tissue culture infectivity doseand incubation period.

Results:According to growth kinetics of cell lines, Vero cell line takes more than 72 hours to reach confluence, where as BHK-21 cell line reach confluence before 72 hours incubation. For Eveninyl rokipinik avelset virus on Vero cell line, the result from titration indicate high virus titer (10^7.75LD₅₀/ml) with the lowest tissue culture infectivity dose(0.001) per cell and high incubation period (96 hours); whereas Pastuer virusvirus on Baby Hamister Kidney -21 show high titer (10^7.50LD₅₀/ml) with highest tissue culture infectivity dose(0.01) per cell and lower incubation period (72 hours) compared to Vero cell line.

Conclusion: For best virus titer during virus culture, 0.001 tissue culture infectivity dosewith 96 hours incubation period on Vero cell and 0.01 tissue culture infectivity dosewith 72 hours incubation period on Baby Hamister Kidney -21 cell were selected for Eveninyl rokipinik avelset and Pastuer virusfixed virus strain respectively.