Advances in Irradiated Livestock Vaccine Research and Production Addressing the Unmet Needs for Farmers and Veterinary Services in FAO/IAEA Member States

Abstract

The Animal Production and Health section (APH) of the Joint FAO/IAEA Centre of Nuclear Techniques in Food and Agriculture at the International Atomic Energy Agency has over the last 58 years provided technical and scientific support to more than 100 countries through co-ordinated research activities and technical co-operation projects in peaceful uses of nuclear technologies. A key component of this support has been the development of irradiated vaccines targeting diseases that are endemic to participating countries. APH laboratories has over the last decade developed new techniques and has put in place a framework that allows researchers from participating member states to develop relevant vaccines targeting local diseases while using irradiation as a tool for improving livestock resources.

Protective Efficacy of H9N2 Avian Influenza Vaccines Inactivated by Ionizing Radiation Methods Administered by the Parenteral or Mucosal Routes

“…On the other hand, it should be noted that the addition of trehalose and performing irradiation under frozen conditions could have increased the gamma irradiation dose needed for the inactivation of the virus because of the protective effects exerted both on viral proteins and the viral genome (53). Not surprisingly other groups who used gamma irradiation to inactivate influenza virus at room temperature and without trehalose achieved complete inactivation at 16 KGy (54).…”

Mucosal Immunity of Major Gastrointestinal Nematode Infections in Small Ruminants Can Be Harnessed to Develop New Prevention Strategies

“…An effective vaccine would need to stimulate many different host immune pathways to sufficiently survive subsequent infection. Using whole irradiated L3 larvae that have lost their ability to establish an infection but are still alive and therefore mimicking a natural infection, ensures that the host is able to induce all the variable, but pertinent immune response is required to prevent infection [117]. It is therefore not surprising that most of the experimental vaccines listed on Table 1 do not confer sterilising immunity but rather reduce parasite shedding to a minimum which, when combined with other integrated control measures, would effectively stop all infection in a herd; e.g., irradiated Trichostrongylus, with an efficacy of almost 80%, is sufficient to prevent disease [118].…”

“…Further experiments with lower radiation doses were also explored [127]. Revived studies using H. contortus parasites irradiated at the lower dose of 200 Gy was effective when used to immunise 4-month-old goats [117]. This would suggest that previous experiments that did not test the viability of irradiated parasites before inoculation failed to provide younger animals with crucial conformational antigens that are necessary for inducing protection.…”

“…This would suggest that previous experiments that did not test the viability of irradiated parasites before inoculation failed to provide younger animals with crucial conformational antigens that are necessary for inducing protection. Using doses that kill instead of producing live but non-infective parasites has negative consequences, especially when immunising younger animals [117]. It would therefore be advisable to analyse the viability of irradiated parasites before immunisation when producing commercial batches.…”

Immune Responses Following Administration of Whole Gamma Irradiated SARS-CoV-2 Vaccine Stabilized With Disaccharide Trehalose on Syrian Hamster Model

“…The irradiation inactivation method has some advantages over chemical inactivation for vaccine production. Recently, irradiation with low-energy electron beams has been shown to be much safer than gamma irradiation with a Co-60 source and can preserve viral and bacterial antigenicity [10]. The aim of this study was to investigate the e cacy of gamma irradiation in inactivating emerging/outbreaking pathogens.…”