Recent antibody testing indicates at least five cases of coronavirus were present in Ohio as early as January, state officials announced Monday.

State Department of Health Director Amy Acton said Monday that the cases in question predate the beginning of February, the previous earliest onset date for the virus in Ohio. Acton said officials are working to confirm whether the earliest cases tie back to travel outside of Ohio.

The state Department of Health announced last week that it will test volunteers from 1,200 households for virus antibodies. Scientists have not yet confirmed whether having previously had the virus confers immunity, but Acton has expressed optimism that it will provide valuable insight into combating the virus regardless.

The state has a total of 24,777 confirmed and probable cases of the virus as of Monday, including 1,357 hospitalizations, 1,217 intensive care unit admissions and 1,357 deaths. Gov. Mike DeWine (R) imposed several restrictions on public activity, including a stay-at-home order on March 23, after the first confirmed cases.

Like several other states, Ohio is in the process of lifting some of those restrictions, allowing retailers to reopen Tuesday and outdoor dining for bars and restaurants on Friday. Indoor dining is set to resume  May 21.

The announcement comes the same day the Food and Drug Administration granted emergency use authorization to Abbott Labs’ new coronavirus antibody test, saying it will ship nearly 30 million tests globally in May and have capacity for 60 million in June.

The drugmaker has vowed the test has the capacity to exclude false positives 99.6 percent of the time and exclude false negatives 100 percent of the time in patients tested 14 days after the onset of symptoms.