Jan. 25, 2022 -- Japanese researchers say the Omicron variant survives longer on plastic and skin than other COVID-19 variants, one possible explanation for why Omicron has spread so rapidly around the world.
In a lab experiment, samples of different variants were applied to pieces of plastic and human skin collected from autopsies, researchers from Kyoto Prefectural University of Medicine wrote in bioRxiv. A variant “survived” until it could no longer be detected on the surface.
“This study showed that the Omicron variant also has the highest environmental stability among VOCs (variants of concern), which suggests that this high stability might also be one of the factors that have allowed the Omicron variant to replace the Delta variant and spread rapidly,” the researchers wrote.
On plastic, the Omicron variant samples survived an average of 193.5 hours, a little more than 8 days. By comparison, the other survival times on plastic were 56 hours for the original COVID strain, 191.3 hours for Alpha, 156.6 hours for Beta, 59.3 hours for Gamma, and 114 hours for Delta.
On skin samples, the Omicron samples survived an average of 21.1 hours. The other variants had these average survival times on skin: 8.6 hours for the original version, 19.6 hours for Alpha, 19.1 hours for Beta, 11 hours for Gamma, and 16.8 hours for Delta.
The study found that the variants had more resistance to ethanol than the original strain of COVID. That said, all COVID samples were inactivated after being exposed to alcohol-based hand sanitizers for 15 seconds.
"Therefore, it is highly recommended that current infection control (hand hygiene) practices use disinfectants ... as proposed by the World Health Organization," the researchers said.
The study has not been peer-reviewed.