For the seventh straight day, Thursday flight delays and cancellations at Logan International Airport messed up travel plans as airlines continue to grapple with persistent staffing shortages related to COVID-19, which resulted in thousands of flights in the US over the holidays Have led soil.

As of 1:00 p.m. Thursday, 65 flights arriving and departing Logan had been canceled and 74 delayed, according to Flight Aware, which is tracking flight cancellations. The early tally comes after 158 Logan flights were delayed and 46 canceled on Wednesday, reflecting a week of disruption that began last Thursday.

JetBlue made up the majority of the cancellations at Boston Airport: The airline had canceled 47 flights by 1 p.m., which made up more than 70 percent of the total cancellations there. JetBlue canceled 175 flights nationwide.

The airline, along with Delta and United, announced last week that the rising Omicron variant had led to staff shortages and forced them to cancel flights. A company spokesman said by email on Thursday that JetBlue is “taking all possible steps to minimize interference from Omicron …”.

“As with many companies and organizations, we have seen an increase in the number of sick leave from Omicron,” said the spokesman. “We started the Christmas season with the highest workforce since the beginning of the pandemic and are using all available resources to meet our staffing needs. In order to let our customers know as early as possible that they can make alternative plans and accommodate them on other flights, we are proactively reducing our flight schedule until January 13th. “

Bad weather has also played a role in some clutter in Logan, which resulted in Cape Cod-based Cape Air, which operates smaller aircraft, canceling more than 40 of its flights on Saturday.

The CDC offered the pandemic-stricken aviation industry a respite on Monday that could help alleviate staffing shortages if the agency were to cut the recommended time a person should be isolated from a COVID-19 infection in half – to five days . Airlines had previously asked the Biden government to reduce the quarantine period to alleviate staffing problems.

The move comes as heavy travel is expected on Sunday January 2nd as people return home after the holidays.

However, JetBlue said Thursday that while the new CDC guidelines will help alleviate some staffing issues, there could be more cancellations in the near future.

“While the new CDC guidelines should help get crew members back to work sooner, and our downsizing of schedule and other efforts will further ease daytime cancellations, we are expecting the number of COVID cases in the Northeast – where the most are of our crew members are resident. “- to continue climbing for the next week or two,” said the spokesman. “This means that the likelihood of further cancellations is high until the number of cases drops.”

Andrew Brinker can be reached at andrew.brinker@globe.com. Follow him on Twitter at @andrewnbrinker.