Respiratory illnesses elevated in 38 states, according to CDC

Respiratory illness activity is elevated or increasing across most areas of the country, according to the latest data from the Centers for Disease Control and Prevention (CDC).

Some 38 states plus New York City are experiencing "high or very high" levels of respiratory illness activity, according to the CDC. Of those states, 21 are experiencing "very high" activity. Last week, 31 states were experiencing "high or very high" activity.

Respiratory illness activity is defined as people going to the doctor with symptoms, including fever and a cough and/or sore throat, from any respiratory disease including flu, COVID-19, respiratory syncytial virus (RSV), and the common cold.

"A steady increase in respiratory illnesses is a common annual trend, typically fueled by holiday gatherings and travel," says ABC News contributor John Brownstein, Ph.D. "This year is no exception. With January and February often marking the peak of such illnesses, it's crucial to exercise heightened vigilance now."

Flu hospitalizations also continue to increase, rising 35% in the most recent week. The CDC estimates that there have been at least 10 million illnesses, 110,000 hospitalizations, and 6,500 deaths from flu so far this season. Adults over 65 have the highest rates of flu hospitalizations.

CDC modeling estimates that flu infections are growing or likely growing in 47 states and territories.

COVID-19 hospitalizations also have increased for eight consecutive weeks, rising 20% in the most recent week but so far remaining lower than the same time last year. Adults over 65 have the highest rates of COVID-19 hospitalizations.

CDC modeling further estimates that COVID-19 infections are growing or likely growing in 42 states and territories.

RSV activity remains elevated in many areas of the country, though decreases have been observed in some areas. Infants under 4 years of age have the highest rates of RSV hospitalizations.

Adults over 65 and American Indian/Alaska Natives, as well as and Asians/Pacific Islanders, have the highest rates of death due to COVID-19, flu and RSV, though COVID-19 remains the main driver of all viral respiratory deaths in those groups.

Health officials recommend that everyone get an updated flu and COVID-19 vaccine, as well as RSV vaccines, if eligible. It's best to get vaccinated a soon as possible, since it often takes up to two weeks after being vaccinated to reach full protection, according to the CDC.

The federal government maintains a national database of vaccine locations at vaccines.gov. You can also call 800-232-0233. For RSV vaccines, the CDC recommends talking to your doctor or health care provider.

"My advice is to prioritize health safety measures like staying home when sick, get vaccinated if you haven't already, and practice good hygiene to prevent the spread of illnesses," Brownstein tells ABC News.