Recovery from Acute SARS-CoV-2 Infection and Development of Anamnestic Immune Responses in T Cell-Depleted Rhesus Macaques.

Severe coronavirus disease 2019 (COVID-19) has been associated with T cell lymphopenia, but no causal effect of T cell deficiency on disease severity has been established. To investigate the specific role of T cells in recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, we studied rhesus macaques that were depleted of either CD4, CD8, or both T cell subsets prior to infection. Peak virus loads were similar in all groups, but the resolution of virus in the T cell-depleted animals was slightly delayed compared to that in controls.

Inactivation of SARS-CoV-2 Laboratory Specimens.

The burden on diagnostic and research laboratories to provide reliable inactivation for biological specimens to allow for safe downstream processing is high during the coronavirus disease 2019 (COVID-19) pandemic. We provide safety data regarding commonly used chemical and physical inactivation procedures that verify their effectiveness against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Recovery from acute SARS-CoV-2 infection and development of anamnestic immune responses in T cell-depleted rhesus macaques.

Severe COVID-19 has been associated with T cell lymphopenia 1,2, but no causal effect of T cell deficiency on disease severity has been established. To investigate the specific role of T cells in recovery from SARS-CoV-2 infections we studied rhesus macaques that were depleted of either CD4+, CD8+ or both T cell subsets prior to infection. Peak virus loads were similar in all groups, but the resolution of virus in the T cell-depleted animals was slightly delayed compared to controls.

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

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 50% tissue culture infectious dose (TCID)/mL ranging from 1 to 5 MRads.

Compatibility of Maximum-Containment Virus-Inactivation Protocols With Identification of Bacterial Coinfections by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry.

Diagnostics and research analyses involving samples containing maximum-containment viruses present unique challenges, and inactivation protocols compatible with downstream testing are needed. Our aim was to identify a validated viral inactivation protocol compatible with bacterial identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We assessed a panel of bacteria with 6 validated maximum-containment virus-inactivation protocols and report that inactivation with TRIzol or γ-irradiation is compatible with MALDI-TOF MS.