The seven-day average for newly reported cases in the U.S. topped 700,000 for the first time, data from Johns Hopkins University show, as the highly infectious Omicron variant spreads throughout the country.

The average of known cases could soon triple the pre-Omicron record set a year ago, when the U.S. briefly saw about a quarter million daily cases. The numbers reported by state health departments and collected by Johns Hopkins also likely reflect a fraction of the true number, due in part to Omicron’s rapid spread and the difficulty many Americans have had getting tested. Some laboratories are limiting test-processing to certain people such as those with symptoms because of the surge in demand.