(CNN) Covid-19 infections are on the rise across the country, with Michigan (+50%) among the states witnessing the largest spikes, according to Johns Hopkins University.
Michigan cases have been climbing since the last week of February, and the state has reported the second highest number of cases of the B.1.1.7 variant, first identified in the United Kingdom.
Those spikes come as health officials prepare to roll out the state's largest mass vaccination site at Ford Field in Detroit.
On Thursday, Michigan Gov. Gretchen Whitmer and other state leaders took center stage at Ford Field to announce that the site -- scheduled to open on March 24 and managed with support from the Federal Emergency Management Agency -- will have the capacity to administer 6,000 shots daily.
"We are in the 4th quarter of this fight against the pandemic. It is not over yet. It is no time to spike the football," Whitmer said. "It is time for us to grit our teeth and keep doing the work we need to do until the last second of this event plays out. If we want to get back to normal...we all need to get vaccinated, encourage our loved ones and friends and co-workers and neighbors to do so."
Dr. Jennifer Morse, medical director at the Mid-Michigan District Health Department, hopes the opening of the clinic will help slow the spread of the virus across the state.
Morse said there is a long list of factors contributing to the spike in cases in Michigan.
One example, she said, is the recent rollback of certain restrictions.
Whitmer eased restrictions earlier this month, increasing capacity limits at restaurants, retail stores and gyms from 25% to 50% capacity, with a maximum capacity of 100 people per locale.
Whitmer told CNN earlier this month that her state has made a lot of progress against the virus but that they will keep "tethered to the science" while easing restrictions.
Morse said the rollback of restrictions has led to poor mask wearing. She also said that news of emerging vaccines led people to believe they could relax some of the their hygiene habits such as wearing masks.
Morse told CNN that a Covid-19 outbreak in a prison in Ionia County and the B.1.1.7 variant have also fueled the recent surge.
Michiganders are also starting to travel more, nearing levels not seen since before the pandemic, Morse said -- a claim backed by data from the Bureau of Transportation.
Morse, who noted that the state has administered more than three million vaccine doses, said she fears progress to combat the virus could be reversed if the trend of rising cases continues.
"My one hope is that we have been really aggressively vaccinating and have been working through the different categories for vaccination quite well," Morse said. "And my hope is that that will help to keep (cases) from climbing as rampantly as (they) did back in the fall."
Michigan Lt. Gov. Garlin Gilchrist shared that hope during Thursday's announcement at Ford Field.
"At the start of the Covid-19 pandemic, Detroit was one of America's epicenters for cases and deaths. And as a Detroiter, I felt this personally having said goodbye to 27 people due to this virus," Gilchrist said, adding that the Ford Field site will allocate 1,000 vaccines daily to mobile vaccine units throughout southeast Michigan. "The virus hit our city hard, but Michiganders are tough. We can come together to combat Covid-19."
Correction: This story has been updated to remove mention of Alabama and Delaware as states reporting a significant rise in Covid-19 infections. The two states have clarified that they recently processed a backlog of cases.