President Biden on Sept. 9 announced sweeping new mandates meant to push an estimated two-thirds of American workers to get the COVID-19 vaccine and stem the tide of the latest Delta wave of the pandemic. The move will require vaccines for health care workers, federal contractors, and the vast majority of federal workers—and require large employers to introduce a “vaccinate or test” plan for their workers. While the U.S. started its vaccination push earlier than most countries, eighteen months into the pandemic it is facing another huge surge of cases and deaths—largely in regions with low vaccination rates. Here, Stanford health law expert Michelle Mello discusses President Biden’s new mandates and the pandemic.

Do you think President Biden’s new mandates will make a significant difference in our fight against COVID?

It’s clear that the proportion of Americans who are fully vaccinated isn’t where we need it to be in order to contain the virus.  The data also clearly show that communities with high vaccination coverage have far fewer COVID-19 cases, hospitalizations, and deaths than communities with lower coverage.

What’s less clear is how much the new mandates will move the needle on vaccination rates among the holdouts.  On the one hand, it’s sensible to think that federal workers will respond to the threat of losing their jobs, and they’re a large group.  Further, most healthcare facilities will welcome the political cover for taking action against unvaccinated workers, and the mandate could be quite helpful in addressing persistently low vaccination rates among lower-skilled healthcare workers such as nurse aides and environmental services workers.

But the Biden plan’s effect on employees of large companies is more uncertain.  Although the employer policy is being referred to as a mandate, it actually just requires companies with 100 or more employees to ensure that their workers are either vaccinated or tested for SARS-CoV-2 at least weekly.  Particularly if the employer makes tests readily available at no cost to employees, and if health insurers remain required to cover people’s cost-sharing for SARS-CoV-2 testing, employees opposed to vaccination may simply choose testing.  That’s certainly a better outcome than having workers unvaccinated and untested, but we may not see a leap in vaccination rates.

Read Full Q&A with Sharon Driscoll at Stanford Law School