Ignoring CDC warnings, more than 1 million passengers have flown from US airports for 10 straight days

New York(CNN Business) Spring break is here and people suffering from a year of cabin fever are throwing caution to the wind. Saturday marked the 10th straight day on which more than 1 million passengers traveled through American airports.

The TSA reported 1,369,180 travelers passed through security checkpoints Saturday, a day after air passengers set a new pandemic record, when 1,468,516 traveled through TSA security.

That's a worrying sign for health experts: Although millions of Americans have been vaccinated, the US Centers for Disease Control and Prevention continues to recommend that people avoid travel. It has so far declined to issue new guidance on travel for vaccinated Americans out of concerns prompted by travel-related surges that the United States encountered during previous holiday periods.

"What we have seen is that we have surges after people start traveling, we saw it after July 4, we saw it after Labor Day, we saw it after the Christmas holidays," CDC Director Dr. Rochelle Walensky said last week in response to a question from CNN's Kaitlan Collins during a Covid-19 briefing.

Walensky said because 90% of people remain unvaccinated, the CDC will wait to update guidance.

A dubious milestone

Despite the CDC's warnings, the US airline industry hit a dubious milestone last week: For the first time since the pandemic began, air travel is up from a year ago.

That's a positive sign for battered airlines, but it's also an incredibly low hurdle to clear. The increase is still a heavily depressed level -- about half the air traffic from pre-pandemic 2019.

Still, the bruised airline industry is looking for signs of pent-up demand for air travel. At the end of the December holiday period, the TSA logged five 1-million-plus days in a row.

In another hopeful sign, airlines are reporting better bookings ahead for this summer, with American Airlines CEO Doug Parker saying Monday that the company is "getting very close to 2019 in total bookings."

All of the airlines are expected to report losses once again in the first quarter, after a combined $32 billion in losses in 2020, excluding special items. But investors are getting more optimistic: Shares of Southwest (LUV), Alaska Air (ALK), JetBlue (JBLU) and Hawaiian Airlines (HA) are already above pre-pandemic levels, while American (AAL), Delta (DAL) and Spirit (SAVE) are close to that benchmark. Only shares of United (UAL) are down significantly from where they were in late January 2020.