Centers for Disease Control and Prevention Director Rochelle Walensky insisted on Monday that Michigan cannot vaccinate its way out of the state’s coronavirus spike, adding that authorities must “shut things down” to curb the spread.

“When you have an acute situation, [an] extraordinary number of cases, like we have in Michigan, the answer is not necessarily to give vaccine,” Walensky said during a COVID-19 response briefing. “In fact, we know that the vaccine will have a delayed response. The answer to that is to really close things down, to go back to our basics, to go back to where we were last spring, last summer.”