Flu activity in the United States is currently low, despite widespread reports of sniffles and coughs. According to the latest data from the U.S. Centers for Disease Control and Prevention (CDC), as of last week, only four states—Colorado, Louisiana, New Jersey, and New York—reported high flu activity. Most areas are experiencing minimal or low levels of flu, which health officials characterize as a “mild” season.
The winter months typically see a rise in various respiratory illnesses, primarily due to increased indoor gatherings that facilitate the spread of germs. This winter, the list of prevalent viruses includes the flu, common colds, and norovirus, a highly contagious pathogen responsible for vomiting and diarrhea. In recent weeks, norovirus cases have shown an upward trend, prompting concern among health professionals.
Flu Season Insights and Concerns
Health experts are particularly vigilant regarding this year’s flu season. Last season was notably severe, with the overall hospitalization rate reaching its highest level since the H1N1 pandemic in 2009. Tragically, pediatric flu deaths also hit an all-time high, with 288 fatalities reported. This week marked the announcement of the first pediatric flu death for the current season, raising alarms about potential challenges ahead.
The CDC has identified the H3N2 strain of the flu virus as a significant concern. Historically, this subtype has led to higher rates of hospitalizations and deaths among older populations. Alarmingly, 89% of the H3N2 infections analyzed so far this season are linked to a new variant, known as the subclade K variant, which differs from the strain included in this year’s flu vaccine. Flu seasons often peak around February, making it difficult to predict the impact of this vaccine mismatch at this stage.
Vaccination remains a crucial defense against the flu. The CDC advises that everyone aged six months and older receive an annual flu shot. As of now, approximately 42% of U.S. adults and 41% of children have been vaccinated this season. While the vaccine may not prevent all flu symptoms, it is effective in reducing the severity of infections, as indicated by preliminary analyses from the United Kingdom.
Other Respiratory Viruses to Monitor
Another virus under scrutiny is respiratory syncytial virus (RSV), which commonly causes cold-like symptoms but can be particularly harmful to infants and the elderly. While RSV seasons typically peak by December or January, reported cases this year have been lower than average, suggesting a later onset.
Dr. Cameron Wolfe, an infectious diseases expert at Duke University, noted that an increase in RSV cases is likely on the horizon. Recent CDC updates indicate rising infections in southern and mid-Atlantic states. Encouragingly, new vaccines for RSV were licensed in 2023 for pregnant women and older adults, along with laboratory-made monoclonal antibodies for infants.
As of October, approximately 41% of Americans aged 75 and older and about 40% of infants are reported to be vaccinated against RSV, according to CDC data.
COVID-19 activity is currently low, a welcome trend following a peak earlier in the summer. Recent CDC research suggests that the COVID-19 vaccine remains effective in preventing severe illness among children. Among those aged nine months to four years, the vaccine showed 76% effectiveness against severe symptoms. For children aged five to 17 years, the effectiveness was recorded at 56%.
Despite the efficacy of COVID-19 vaccines, vaccination uptake has been low this season. Only about 7% of children and 15% of adults have received the latest version of the vaccine, according to CDC statistics. In October, the CDC revised its recommendations, leaving vaccination decisions to individuals, a move that has raised concerns among health professionals regarding public health safety.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation, but the AP maintains full editorial control of all content.
