The Omicron variant of the novel coronavirus might cause less damage to the lungs, a series of new studies, mostly on animals like mice and hamsters, suggest. The research, which began after Omicron was first reported in South Africa in November, is in its early stages, and has not yet been published in scientific journals. But a number of new studies suggest the variant may cause less scarring to the lungs than previous variants. Researchers said their work—some of it in rodents—shows Omicron infections targeting the upper respiratory system, like the throat. Those findings might shed new light on early Omicron trends, like a relatively low rate of hospitalizations. Still, scientists are cautious in ascribing the hospitalizations to a single cause. In South Africa, where Omicron spread early, many of the patients were young, or had already been vaccinated or survived a previous variant—all factors that can lower risk of serious illness. And as ever, some experts urged caution on over-extrapolating limited studies primarily done on animal rather than human tissue.