LOS ANGELES - Respiratory illnesses are ticking up in the United States ahead of holidays with hospital admissions for COVID-19, flu and respiratory syncytial virus (RSV) reaching their highest levels since the start of this year.

The amount of respiratory illness causing people to seek healthcare is elevated or increasing across most areas of the country, according to the US Centers for Disease Control and Prevention (CDC).

More than 22,700 new COVID hospital admissions were reported across the country in the week ending Dec 9, the highest since February, according to the latest data released by the CDC on Monday.

Nationally, laboratory test positivity for influenza and emergency department visits due to influenza is increasing, according to the CDC.

Seasonal influenza activity is elevated in most parts of the country, with the southeast, south-central, and west coast areas reporting the highest levels of activity, according to the CDC weekly review.

The number of weekly flu hospital admissions continued to increase.

So far, there have been at least 3.7 million illnesses, 38,000 hospitalizations, and 2,300 deaths from flu this season in the United States, according to the CDC.

Children's hospitals in the United States confronted a violent wave of RSV last year, which can be dangerous for small children, especially infants, and some were overwhelmed.

This year, RSV appears to have stabilized and peaked nationwide, according to the CDC.

CDC Director Mandy Cohen urged Americans to get vaccinated, especially ahead of year-end holidays; to order free at-home coronavirus tests; and to consider adopting the usual precautions, including regular hand washing, opening windows for ventilation and wearing a mask.

Yet vaccine uptake of COVID-19, influenza, and RSV remains low in the country.

The percentage of the population reporting receipt of the updated COVID-19 vaccine is 7.8 percent for children and 18.3 percent for adults over 18 years of age, including 37.4 percent among adults age over 65, according to CDC data.

The flu vaccine coverage is 43.3 percent for children and 42.2 percent for adults over 18 years of age, including 69.3 percent among adults age over 65, CDC data showed.

There is "urgent need" to boost vaccination coverage as flu, COVID cases continue to rise nationally, said the CDC.