DHS Report: Environment unlikely to affect transmissibility of SARS-COV-2 variants

New research from the Department of Homeland Security (DHS) Science and Technology Directorate (S&T) has found that the deactivating effects of heat and sunlight are consistent across different variants of the SARS-COV-2 virus – the virus that causes COVID-19.

In a report published in the Journal of Infectious Diseases, S&T surmised that increased transmissibility of certain variants is not due to any differences in environmental survivability.

“There is still a lot for scientists to learn about SARS-CoV-2, the variants that have emerged, and what contributes to their transmission in the community,” said Dr. Lloyd Hough, lead for S&T’s Hazard Awareness & Characterization Technology Center (HAC-TC). “But this research shows that the stability of these variants in the environment is about the same and that the risk assessments and tools that S&T produced early in the pandemic are still applicable.”

Researchers found that decay rates in the virus variants are strongly affected by simulated sunlight and somewhat affected by temperature and relative humidity.

Early in the COVID-19 pandemic, researchers with the National Biodefense Analysis and Countermeasures Center (NBACC) at Fort Detrick, Md., found that environmental conditions like sunlight, heat, and humidity affect the stability of SARS-COV-2. As new strains of the virus emerge, researchers studied isolates from multiple variants (including one belonging to the UK variant) to determine if there were stability differences in them that might affect their potential for transmission.

Researchers concluded that while certain variants may spread faster or be more lethal, they are similarly affected by the environment, and that differences in transmissibility are not likely due to differences in stability.