COVID-19 variants have similar surface stability as the wild type virus under laboratory conditions but can be effectively eliminated by disinfection and thorough hand washing, heat or alcohol treatment, German researchers have found.

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The team, led by researchers of the Ruhr-Universitat Bochum (RUB), analysed how long the variants remain infectious on surfaces made of steel, silver, copper and on face masks and how they can be rendered harmless by means of soap, heat or alcohol. It turned out that both variants, as well as the wild type virus, could be inactivated when treated with at least 30 per cent alcohol for at least 30 seconds. "Common disinfectants are therefore effective against all these variants", said Stephanie Pfander from the RUB.

Handwashing with soap could also lower the risk of infection. Heat also works against the virus: after 30 minutes at 56 degrees Celsius, all variants were rendered harmless, Pfander added. To find out whether the stability of the different mutant variants on surfaces differs from each other, the team analysed the number of infectious virus particles on surfaces made of steel, copper, silver and on surgical and FFP2 masks over 48 hours. "The surface stability did not differ between the virus variants", said Eike Steinmann from the Department for Molecular and Medical Virology at RUB. "As described several times before, copper, in particular, has a very strong anti-viral effect".

The results, published in the Journal of Infectious Diseases, did not detect any differences between the different mutants in terms of their sensitivity to different hygiene measures. The fact that viruses change genetically over time is well known. Variants of concern are those that give the virus an advantage, for example by allowing it to replicate faster, become more infectious or enable it to evade the immune response. The British and South African variants have accumulated several mutations which result in an increased transmission and, in some cases, lead to more severe courses of disease.