London (CNN Business)The Omicron variant of the coronavirus is spreading fast. But even as scientists urge patience while they assess the severity of the strain and its impact on the efficacy of vaccines, the travel industry is feeling the pain.
"We've seen a little bit of a waver in the bookings," Nick Calio of the lobby Airlines for America said during an industry press briefing on Monday.
What's happening: The S&P 500 finished last week at a record close. But stocks in hotels, tour providers and airlines — which required emergency funding to make it through previous Covid-19 waves — remain vulnerable to Omicron fears.
Shares of American Airlines (AAL) fell 5% on Monday, as did cruise line Carnival Corporation (CCL). Marriott International (MAR) dropped more than 4%.
These stocks have seen significant moves in both directions in recent weeks. But industry leaders are making clear that tighter government rules around travel, as well as customer anxieties, are having an impact.
In a letter to UK Prime Minister Boris Johnson, the chief executives of British Airways, Virgin Atlantic, Ryanair (RYAAY) and easyJet said "haphazard and disproportionate" travel restrictions risk "permanent scarring" of the industry.
They're urging the government to scrap all emergency testing for fully vaccinated passengers.
Willie Walsh, head of the International Air Transport Association, said at a press briefing last week that when new variants are discovered, airlines bear the brunt of the economic damage. He pointed to "reductions in capacity following the new travel restrictions that were introduced recently."
"We cannot keep shutting down aviation and shutting down economies, when in reality, it's not providing any measures to restrict the transmission of the virus and more importantly, it's doing huge damage to the industry," Walsh said.
An unprecedented drop-off in passengers due to the pandemic has led to almost $700 billion in revenue losses for airlines, according to an assessment published last week by the UN's International Civil Aviation Organization.
Some companies will need help to withstand another blow. Take Virgin Atlantic. Billionaire Sir Richard Branson's Virgin Group and Delta Air Lines said Monday that they were pumping £400 million ($530 million) into the carrier, which doesn't expect to return to "sustainable profitability" until 2023.
And yet: There are signs that despite the uncertainty, Covid-fatigued passengers are determined to keep flying, which may limit the impact.
The US Transportation Security Administration is preparing for a crush of travelers over the holidays. About 2.1 million people passed through airport security checkpoints this past Sunday.