NEW YORK - The U.S. flu season has started, with health officials reporting high levels of illnesses in at least seven states and cases on the rise in other parts of the country, according to the Centers for Disease Control and Prevention (CDC).

The latest data released by the CDC on Friday revealed a significant flu activity in Louisiana last week, while Alabama, Florida, Georgia, Mississippi, New Mexico, and South Carolina reported high levels of flu activity as well. The District of Columbia and Puerto Rico, where health officials declared an influenza epidemic earlier this month, also had high activity.

Moderate yet increasing flu activity was observed in New York City, Arkansas, California, Maryland, New Jersey, North Carolina, Tennessee, and Texas. However, Alaska, which has been experiencing high flu activity for weeks, did not report data last week.

Tracking the flu during the season relies on various indicators, with reports from doctor's offices and hospitals playing a crucial role. It is important to note that many individuals with flu-like symptoms are not tested, leading to unconfirmed infections. Additionally, the presence of COVID-19 and other respiratory viruses can complicate the assessment of flu activity.

Alicia Budd, the leader of the CDC's flu surveillance team, emphasized that multiple indicators point to ongoing increases in flu activity. The flu viruses circulating this year are diverse, with the strain that is currently predominant typically causing fewer hospitalizations and deaths among the elderly, who are usually most affected by the flu.

According to the CDC's estimates for this fall, there have been at least 780,000 flu illnesses, 8,000 hospitalizations, and 490 flu-related deaths, including one child. While the exact effectiveness of the current flu vaccines is yet to be determined, Budd stated that the vaccines are well-matched to the flu strains circulating.

In terms of vaccination rates, approximately 35% of U.S. adults and 33% of children have received the flu vaccine, as per the latest CDC data. However, these rates are lower compared to last year for both adults and children. Despite the lower flu vaccination rates, they are still higher than the rates for the recommended COVID-19 and RSV shots. Only around 14% of adults and 5% of children have received the COVID-19 vaccine, while approximately 13.5% of adults aged 60 and older have received the RSV vaccine introduced earlier this year.

As the U.S. enters the flu season with high activity levels in several states, health officials continue to stress the importance of flu vaccination to mitigate the impact of the virus and protect vulnerable populations, especially during the ongoing COVID-19 pandemic.