LOS ANGELES, Nov. 22 (Xinhua) -- As tens of millions of Americans started to travel for Thanksgiving, experts warned that "tripledemic" cases of COVID-19, RSV (respiratory syncytial virus) and flu are on the rise in the United States.
Nearly 55 million Americans are expected to travel during the long holiday weekend, according to AAA estimates.
On Monday, the U.S. Federal Aviation Administration (FAA) said this Tuesday will be one of the busiest travel days before Thanksgiving, with over 48,000 flights across the country anticipated. The FAA estimates nearly 400,000 flights to soar over the United States from Nov. 19 to 27, with 23,000 flights scheduled on Thanksgiving Day.
As Americans head into the holiday season, health experts anticipate that the country could see a fresh wave of respiratory illnesses as more people travel and gather indoors.
Experts are concerned about the confluence of influenza, RSV and coronavirus, warning grim threats from a "tripledemic."
Two new Omicron subvariants, BQ.1 and BQ.1.1, have overtaken BA.5 to be the dominant strains in the United States. BQ.1.1 made up about 24.2 percent of circulating variants in the week ending Nov. 19, and BQ.1 was estimated to make up 25.5 percent, according to the latest data of the U.S. Centers for Disease Control and Prevention (CDC).
Preliminary data suggests the two variants, descendants of Omicron's BA.5 subvariant, are better at evading immunity from COVID-19 vaccines, including the new bivalent boosters, or a previous COVID-19 infection than past versions of Omicron.
That may give the two subvariants higher transmissibility, which could fuel a rise in cases this winter.
A rapidly intensifying flu season is straining hospitals already overburdened with patients sick from COVID-19, RSV and other respiratory infections.
The CDC estimates that so far this flu season, there have been at least 4.4 million illnesses, 38,000 hospitalizations, and 2,100 deaths from flu.
More than half of the U.S. states have high or very high levels of flu, according to a government report released Friday. Those 27 states are mostly in the South and Southwest but include a growing number in the Northeast, Midwest and West.
CDC data shows that more than 26,000 RSV tests came back positive between Oct. 30 and Nov. 12, a significantly higher number than what was recorded at the same time last year.
RSV is a common respiratory virus that usually causes mild, cold-like symptoms. But it is particularly dangerous for children under two because they have smaller windpipes that collect more mucous, and lungs that need more support for breathing, according to the CDC.
"We are in the midst of a true 'tripledemic,'" said Dr. Jake Lemieux, assistant professor of medicine at Harvard Medical School and an infectious disease specialist at Massachusetts General Hospital. "There are many warning flags regarding the holiday season ahead."
Health experts are encouraging people to get vaccinated and practice safety precautions during the upcoming holidays.