A vaccine mandate for domestic flights may be something to “seriously consider” to protect against the Omicron variant of COVID-19, Dr. Anthony Fauci said Monday in an interview on MSNBC.

Fauci described a hypothetical mandate as a way to encourage more Americans to get vaccinated. In particular, he expressed hope that this would encourage more unvaccinated Americans to reconsider their choice to forgo the vaccine and that way take some pressure off the hospital system by reducing case numbers.

“When you make vaccination a requirement, that’s another incentive to get more people vaccinated,” Fauci said on "Morning Joe." “If you want to do that with domestic flights, I think that’s something that seriously should be considered.”

There is currently no vaccination mandate for domestic flights. For international visitors to the U.S., there is a vaccination requirement for entry, but domestic flights are limited to COVID-19 testing and a federal mask mandate.

The emergence of Omicron has contributed to growing anxiety over the strain’s contagiousness. Fauci, like other medical experts, noted that Omicron’s symptoms are comparably mild compared to earlier variants, but he cautioned that it can amplify the burden created by more hospitalizations.

"The group we're really concerned about is the unvaccinated people because even if this virus is inherently less severe, just the volume of the number of cases that we're going to have could actually put a stress on the hospital system," Fauci said.

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