The death of Supreme Court Justice Ruth Bader Ginsburg and the pending lawsuit against the Affordable Care Act has intensified uncertainty about the law’s future. One consequence if the ACA were struck down would be the elimination of access to Medicaid for about 12 million people in the middle of a deadly pandemic.

Researchers Karen Clay, Joshua A. Lewis, Edson R. Severnini and Xiao Wang recently looked at the impact of Medicaid on mortality in two previous pandemics. Their working paper compares infant mortality in the U.S. during the 1957-58 flu pandemic and the 1968-69 flu pandemic. Both pandemics caused around 100,000 deaths in the U.S. respectively and affected infants disproportionately. But in between, Medicaid was introduced in 1965.

The researchers found that states where more people were eligible for Medicaid saw a 6-7% decrease in overall infant mortality (between 2,646 to 2,777 infant deaths) during the 1968-69 pandemic compared to the 1957-58 pandemic. They found that much of the improvement in infant mortality came from far fewer newborns dying in the first day after their birth, suggesting that Medicaid’s impact could’ve come from improved maternal health or better acute care access at birth. Their evidence further suggests that the mortality improvements were too large to attribute just to Medicaid recipients, suggesting the introduction of Medicaid may have helped limit virus spread and benefited non-Medicaid recipients as well.

With the Medicaid expansion seemingly at risk and the COVID-19 pandemic continuing to rage, this paper offers us a chance to revisit the origins of public policy geared toward covering lower income populations and learn what Medicaid has done for pandemic influenza health risks in the past.

Kosali Simon is a health economist and professor at Indiana University. She studies health insurance and health policy.