According to this take it is well-settled law from previous epidemics that this is constitutional. "In 1824, the Supreme Court in Gibbons v. Ogden alluded to a

According to this take it is well-settled law from previous epidemics that this is constitutional. "In 1824, the Supreme Court in Gibbons v. Ogden alluded to a state’s authority to quarantine under the police powers. In 1902, the Court directly addressed a state’s power to quarantine an entire geographic area in Compagnie Francaise de Navigation a Vapeur v. Louisiana State Board of Health, where both the law and its implementation were upheld as valid exercises of the state’s police power. A shipping company in this case challenged an interpretation of a state statute that conferred upon the state board of health the authority to exclude healthy persons, whether they came from without or within the state, from a geographic area infested with a disease. The shipping company alleged that the statute as interpreted interfered with interstate commerce, and thus was an unconstitutional violation of the Commerce Clause. The Court rejected this argument, holding that although the statute may have had an effect on commerce, it was not unconstitutional. In a subsequent case, the Court made clear that at least where Congress has not taken action, it is “well settled” that states may impose quarantines to prevent the spread of disease even though quarantines “affect interstate commerce." Pages 8-9 of "Federal and State Quarantine and Isolation Authority" by the Congressional Research Service (2014) https://fas.org/sgp/crs/misc/RL33201.pdf https://fas.org/sgp/crs/misc/RL33201.pdf