X-ray irradiation has become a crucial tool for virus inactivation, balancing effective pathogenneutralization with or without the preservation of viral structural integrity. This technique is widelyemployed in virology for applications such as vaccine development, diagnostic research, and the safehandling of pathogenic samples.

The significance of X-ray irradiation is underscored by its ability to inactivate viruses with or withoutcompromising their biochemical and immunological characteristics. Research has demonstrated thatoptimized X-ray doses effectively inactivate zoonotic RNA viruses, such as Zika, Hazara, Bebaru, and RiftValley Fever (Afrough, et al, 2020). Moreover, X-ray irradiation facilitates the safe transfer and analysis ofinactivated viruses in laboratories with lower biosafety levels.

Classification of Viral Resistance to Irradiation

Viruses exhibit varying degrees of resistance to ionizing radiation, primarily influenced by their genomiccomposition and structural complexity:

• High Resistance: Prion diseases such as kuru, Creutzfeldt-Jakob disease, and scrapie exhibitextreme resistance to ionizing radiation. Even high doses (up to 200 kGy) have shown minimalreduction in viral titers, suggesting a unique structure compared to other mammalian viruses.
• Moderate Resistance: Non-enveloped viruses, including adenoviruses and parvoviruses,demonstrate moderate resistance due to their robust capsid structures.
• Low Resistance: Enveloped viruses such as influenza and herpesviruses are more susceptible toirradiation, as their lipid envelopes are prone to damage.

Applications of X-ray Irradiation in Virology (Figure 1)

X-ray irradiation serves multiple critical functions in virology, including:

1. Complete Inactivation for Safety: Ensuring complete virus inactivation is essential for safehandling and study. X-ray irradiation has been used to inactivate high-consequence pathogens,such as Ebola and Lassa viruses, making them safer for research in standard laboratory conditions.

2. Facilitating Research in Lower Biosafety Laboratories: Inactivating viruses enables their safetransfer to lower biosafety-level labs, reducing the need for high-containment facilities whileallowing broader research access .

3. Studying Viral Pathways: X-ray irradiation allows researchers to investigate viral entrymechanisms, replication processes, and interactions with host cells without infection risks.

4. Sequencing and Genomic Studies: By inactivating viruses, irradiation enables safe viral nucleicacid extraction and sequencing, aiding genomic research and the development of molecular diagnostics.

5. Vaccine Development: X-ray irradiation is used to inactivate viruses while preserving theirimmunogenicity, which is essential for developing vaccines that induce strong immune responseswithout causing disease.