The CDC is backpedaling after the White House Coronavirus Task Force warned states in a January memo that a U.S. COVID-19 variant that’s more easily transmissible may be contributing to the country’s disturbing spike in cases.

In fact, that variant may not exist at all.

“This fall/winter surge has been at nearly twice the rate of rise of cases as the spring and summer surges. This acceleration suggests there may be a USA variant that has evolved here, in addition to the UK variant that is already spreading in our communities and may be 50% more transmissible,” reads the Jan. 3 report obtained by CNN. It also calls for “aggressive mitigation ... to match a much more aggressive virus.”

The task force said that without widespread mask wearing and social distancing, “epidemics could quickly worsen as these variants spread and become predominant.”

But The New York Times reports that CDC officials tried to have those “speculative” statements—attributed to Dr. Deborah Birx—removed from the reports, only to be unsuccessful. An agency spokesperson told the paper, “To date, neither researchers nor analysts at C.D.C. have seen the emergence of a particular variant in the United States.”