The British Airways owner said cancelling and rescheduling flights has so far hit planned seat capacity by kilometres by 1-2%.
Demand is dropping as industry events and corporate trips are cancelled, but the airline said it is “strongly positioned for the expected recovery in demand”.
“IAG is resilient with a strong balance sheet and substantial cash liquidity to withstand the current weakness,” the firm said.
The FTSE 100-listed group had to suspend all flights to mainland China as well as reducing routes to Hong Kong, Seoul and Italy.
While the short-haul capacity has not been redeployed, some of the freed-up long-haul capacity has been salvaged by adding flights to India, South Africa and the US.
No guidance is problematic
Neil Wilson from Markets.com said the lack of guidance is "a real concern" and corporate travel could face a US$560bn hit from the virus.
"We can already see non-essential business travel being hit as companies take action to protect employees - families will start to do the same if we a broad spread across Europe," he commented.
"You could see a complete wipeout to the European summer season if the situation deteriorates in Italy and we for instance see a similar surge in cases across France."
Revenue up but profits dip in 2019
In the year to 31 December, revenue rose 5% to €22.4bn, while available seats per kilometre were up 4% to 337,750.
Underlying profit before tax dipped 1% to €2.9bn after costs of €170mln following strikes at British Airways and disruption at its IT systems during the summer.
Full-year dividend was lifted 2% to €0.315 per share.
Shares tanked 8% to 474.18p on Friday morning.
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