The Use of Gamma Radiation for the Preparation of Virus Vaccines

Exposure of Venezuelan equine encephalomyelitis (VEE) virus (at-70 C) to 6 x 106 r y-radiation (6WCo) resulted in loss of lethality for young adult mice and guinea pigs, and loss of capacity to produce plaques or cyLopathic effects in tissue culture. The suckling mouse was more sensitive for detecting live virus in radiated suspensions than was the adult mouse or guinea pig. Live virus was demonstrable in preparations exposed to 6 X 106 r but not in suspensions exposed to 8 X 106 r and more. The rate of inactivation of VEE virus by 7-radiation was an exponential function of the dosage.

mentioning

confidence: 83%

Inactivation of Venezuelan Equine Encephalomyelitis Virus by γ-Radiation

Reitman¹,

Tribble²

1967

“…A number of viruses capable of infecting man have been isolated from food and food animals (1,2,4,5,9,11,12,16,20,22,23,29,31), and extensive studies on viral inactivation by gamma radiation have been reported (3,6,7,15,18,19,24,25,(26)(27)(28). However, only one investigation dealt with inactivation of viruses in food processing.…”

mentioning

confidence: 99%

Gamma Radiation Inactivation of Coxsackievirus B-2

Sullivan¹,

Scarpino²,

Fassolitis³

et al. 1973

The radioresistance of coxsackievirus B-2 was studied when the virus was suspended in Eagle minimal essential medium, distilled water, cooked ground beef, and raw ground beef and irradiated at various temperatures in a cobalt-60 gamma radiation source. The number of surviving viruses at given doses of radiation was determined by a plaque assay system. All destruction curves indicated a first-order reaction. When the virus was irradiated in minimal essential medium at temperatures of-30,-60, and-90 C, D values (in Mrad) were 0.69, 0.59, and 0.64, respectively. When the virus was suspended in water and irradiated at-90 C, the D value was 0.53. Cooked ground beef containing the virus was irradiated at temperatures ranging from 16 to-90 C. The D values were 0.70 (16 C), 0.76 (0.5 C), 0.68 (-30 C), 0.78 (-60 C), and 0.81 (-90 C). Raw ground beef containing the virus was irradiated at-30,-60, and-90 C, and the D values were respectively 0.75, 0.71, and 0.68. The D values indicate that the rate of viral inactivation was dependent on the suspending menstrum.

“…The X rays and gamma rays that are used for inactivation are short wavelength electromagnetic radiations that have high penetrating ability and have the desired characteristic of not imparting radioactivity to the exposed material. Studies with bacterial and animal viruses have shown that infectivity of viruses may be selectively destroyed by radiation while leaving antigenicity intact (4,7,11).…”

mentioning

confidence: 99%

Gamma-Irradiated Venezuelan Equine Encephalitis Vaccines

Reitman¹,

Tribble²,

Green³

1970

The efficacy of Formalin-inactivated Venezuelan equine encephalitis (VEE) vaccine has been reported to be low for man. Although a live VEE vaccine has been shown to be highly effective for the protection of laboratory workers, local and systemic reactions have occurred in approximately 20% of inoculated individuals. Therefore, studies were initiated in an attempt to produce an inactivated vaccine of high potency with low toxicity. Inactivated VEE vaccines were prepared by exposing virus suspensions to 8 x 106 or 10 X 106 r of gamma radiation. Irradiated VEE vaccines prepared from virus suspensions produced in Maitland-type chick embryo (MTCE) cell cultures and in monolayer cultures of human diploid strain WI-38 cells were highly immunogenic for mice and guinea pigs. Guinea pigs vaccinated with a series of three inoculations of vaccine (MTCE) survived challenge with at least 108.4 mouse intracerebral 50% lethal doses of VEE virus. Irradiated vaccines induced high levels of serum-neutralizing and hemagglutinin-inhibiting antibodies in guinea pigs and rabbits. These findings suggest that ionizing radiation may be effective in the preparation of an inactivated VEE vaccine.