Gamma Irradiation as an Effective Method for Inactivation of Emerging Viral Pathogens

Abstract

Gamma irradiation using a cobalt-60 source is a commonly used method for the inactivation of infectious specimens to be handled safely in subsequent laboratory procedures. Here, we determined irradiation doses to safely inactivate liquid proteinaceous specimens harboring different emerging/reemerging viral pathogens known to cause neglected tropical and other diseases of regional or global public health importance. By using a representative arenavirus, bunyavirus, coronavirus, filovirus, flavivirus, orthomyxovirus, and paramyxovirus, we found that these enveloped viruses differed in their susceptibility to irradiation treatment with adsorbed doses for inactivation of a target dose of 1 × 10 6 50% tissue culture infectious dose (TCID 50 )/mL ranging from 1 to 5 MRads. This finding seemed generally inversely correlated with genome size. Our data may help to guide other facilities in testing and verifying safe inactivation procedures.Efficient and reliable inactivation of specimens is an important component of many laboratory operations, but especially critical for biocontainment laboratories handling emerging/reemerging pathogens causing neglected tropical infectious diseases of epidemic as well as infectious disease of regional and global (pandemic) public health importance. Multiple methods can be applied following approved safety testing by institutional and national authorities including those based on chemical, heat, and radiation treatment.

The role of environmental factors to transmission of SARS-CoV-2 (COVID-19)

“…In the meantime, the use of radiation is preferable to other methods (Card et al 2020;Cramer et al 2020;Kenney et al 2020). Gamma CO60 with a dose of 10 KG can sterilize the N95 mask used in SARS-COV environments, and kill the virus (Feldmann et al 2019). However, high doses of radiation may damage the fibers of the mask and allow air to pass through without purification, but it does not have secondary radiation and its side effects (Harrell et al 2018).…”

Disposable N95 Masks Pass Qualitative Fit-Test But Have Decreased Filtration Efficiency after Cobalt-60 Gamma Irradiation

“…Two major considerations must be made when re-sterilizing masks: (1) the sterilization method effectively kills pathogens, penetrating into the fibers of the mask, and (2) the method does not degrade the operational integrity of the N95 filters.We studied Cobalt-60 ( 60 Co) gamma irradiation as a method of effective sterilization without inducing mask degradation. Significant literature exists supporting the use of gamma radiation as a sterilization method, with viral inactivation of SARS-CoV reported at doses of at most 10 kGy [3], with other studies supporting 5 kGy for many types of viruses [4]. However, concerns have been raised about the radiation damaging the fiber material within the mask, specifically by causing cross-linking of polymers, leading to cracking and degradation during fitting and/or deployment [5,6].A set of 3M 8210 and 9105 masks were irradiated using MIT's 60 Co irradiator.…”

Low dose radiation therapy for COVID-19 pneumonia: is there any supportive evidence?

“…At extremely high dose (10 kGy), low-LET radiation has been reported to inactivate MERS-CoV and SARS-CoV (Kumar et al 2015;Feldmann et al 2019). On the other hand, at much lower dose, viral reactivation may occur as reported for various viruses, such as Epstein-Barr virus (EBV, e.g.…”