California has built up a substantial network of laboratories to look for concerning coronavirus variants over the past year, and now the scientists running those labs are developing creative new strategies to quickly identify omicron.

At UCSF, one team is studying wastewater — including effluent from San Francisco International Airport — for signs of the newest variant, which has not yet been found in the United States but is likely already here. The head of the Stanford Clinical Virology Laboratory hopes to narrow the search for omicron by focusing on one mutation that it happens to be missing. Some scientists plan to use a simple diagnostic test to speed up the hunt.