Flu activity remains low across much of the United States this winter, but health officials express concern over a potential surge in virus cases as the season progresses. According to recent data from the U.S. Centers for Disease Control and Prevention (CDC), flu activity is currently classified as high in only four states: Colorado, Louisiana, New Jersey, and New York. Most other states report minimal or low activity levels, indicating that the current flu season is mild so far.
Despite this relatively calm situation, there are several factors that could lead to increased hospitalizations and illness in the coming weeks. Last year’s flu season was notably severe, with a hospitalization rate that was the highest since the H1N1 pandemic in 2009. The CDC reported 288 pediatric flu deaths for the 2022-2023 season, matching the toll from the previous pandemic. This season has already seen its first reported child flu death, raising alarms among health experts.
Concerns Over H3N2 Strain and Vaccination Rates
One particular strain of the influenza virus, known as H3N2, is commonly associated with higher hospitalization and mortality rates, especially among older adults. So far this season, H3N2 infections have been prevalent, with 89% of the cases analyzed being a new variant, the subclade K. This variant differs from the strain included in this year’s flu vaccine, leading to concerns that the vaccine may not be as effective as hoped.
Flu seasons typically peak around February, leaving ample time for infections to rise. The CDC advocates for vaccination, recommending that everyone aged six months and older receive an annual flu shot. Current data indicates that around 42% of U.S. adults and 41% of children have received their vaccinations this season. While the vaccine may not prevent all flu symptoms, it is effective in reducing the severity of the illness, according to preliminary analyses from the UK.
Monitoring Other Respiratory Viruses
In addition to influenza, health experts are keeping a close watch on other seasonal respiratory viruses, particularly Respiratory Syncytial Virus (RSV). This virus often causes mild cold-like symptoms but can be dangerous for infants and the elderly. Traditionally, RSV peaks between December and January, but this year, reported cases have been relatively low so far. Dr. Cameron Wolfe, an infectious diseases expert at Duke University, indicated that an increase in RSV cases is likely, particularly in the southern and mid-Atlantic states.
Recent advancements in vaccination for RSV may be contributing to a decrease in severe cases. In 2023, new vaccines have been licensed for pregnant women and older adults, along with laboratory-made antibodies for infants. As of October, approximately 41% of Americans aged 75 and older have been vaccinated against RSV, alongside 40% of infants.
The Trump administration recently announced a review of two injectable drugs designed to protect young children from RSV, despite no reported safety issues. This decision has raised concerns among public health advocates regarding the potential impact of vaccine skepticism on immunization efforts.
COVID-19 cases are also currently low, with data showing that the vaccine effectively reduces severe illness in children. A CDC study indicated that the COVID-19 vaccine was 76% effective in preventing severe symptoms in children aged nine months to four years, and 56% effective for those aged five to seventeen. However, vaccination uptake remains low, with only about 7% of children and 15% of adults receiving this season’s COVID-19 vaccine.
As the winter virus season progresses, health officials continue to emphasize the importance of vaccination and monitoring for respiratory illnesses, highlighting the need for vigilance as transmission rates may rise in the coming months.
