Kanishka and Humeyra Singh

WASHINGTON, (Reuters) – U.S. airlines cancelled hundreds of flights on Sunday due to rising COVID-19 infection rates. This was caused by the Omicron variant which is highly transmissible and has forced thousands of holiday weekend travellers to alter their plans.

According to FlightAware.com, 656 commercial airlines cancelled flights into, or out of, the United States, on Sunday. This is slightly less than nearly 1000 cancellations on Christmas Day, and almost 700 on Christmas Eve.

Additional cancellations are possible, and over 920 flights were delayed.

Christmas is a busy time to fly, however, the Omicron virus has caused a rapid rise in COVID-19 infection rates, causing airlines to cancel flights and quarantine crew members.

Delta Air Lines Inc (NYSE 🙂 expects more than 300 flights to be cancelled on Sunday.

“Winter weather in portions of the U.S. and the Omicron variant continued to impact Delta’s holiday weekend flight schedule,” a Delta spokesperson said in an emailed statement, adding that the company was working to “reroute and substitute aircraft and crews to get customers where they need to be as quickly and safely as possible”.

A spokesperson explained that it coordinated with affected customers for the next available flight when this wasn’t possible.

FlightAware data worldwide showed that almost 2,150 flights had been called off Sunday, and 5,798 more were in delay as of 9:40 AM EST (1440 GMT).

Omicron was discovered for the first times in November. It now affects nearly three-quarters (or even 90%) of U.S. patients. A Reuters count shows that the number of U.S. coronavirus infections has increased from 45% per day to 179,000 per week over the past week.

Recent research has shown Omicron causes milder illnesses and lower rates of hospitalizations than other COVID-19 variants. However, officials in the health sector remain cautious about this possibility.