Flu activity across the United States remains low this season, with a few exceptions, but health officials express concern about potential increases in severity as winter progresses. According to the U.S. Centers for Disease Control and Prevention (CDC), as of last week, flu activity was categorized as high in only four states: Colorado, Louisiana, New Jersey, and New York. Most other regions are reporting minimal or low levels of flu cases.
While the current indicators are still within the bounds of a “mild” flu season, health authorities are alert to rising severity metrics. Other respiratory illnesses, such as colds and norovirus, traditionally peak during winter months due to increased indoor gatherings, contributing to a rise in infections. Notably, norovirus cases have been trending upward recently.
Concerns Over Flu Severity This Season
Last year’s flu season was particularly severe, marked by the highest overall hospitalization rate since the H1N1 pandemic in 2009. The CDC reported a total of 288 pediatric flu deaths for the season, matching the number recorded during the 2009-2010 pandemic. Just this week, the first pediatric flu death of the current season was confirmed.
Health experts are apprehensive that this winter could bring similar challenges, especially with the H3N2 strain of the flu virus being the most frequently reported this season. Historically, this strain has been responsible for significant hospitalizations and fatalities among older adults. Alarmingly, 89% of the analyzed H3N2 infections have been identified as the subclade K variant, which differs from the strains included in this year’s flu vaccine. Given that flu seasons typically peak around February, it remains uncertain how this mismatch will affect public health.
Vaccination is strongly recommended for everyone aged six months and older, though only approximately 42% of U.S. adults and 41% of children have received flu shots this season, according to CDC data. While the vaccine may not entirely prevent flu symptoms, it can significantly reduce the risk of severe illness.
RSV and COVID-19 Also Under Surveillance
Respiratory syncytial virus (RSV) is another area of concern for health officials. It causes cold-like symptoms but can be particularly dangerous for infants and the elderly. Typically, RSV peaks between December and January, but this season has shown a delayed onset, with current case numbers remaining relatively low, according to the CDC. Dr. Cameron Wolfe, an infectious diseases expert at Duke University, suggested that there may be an uptick in RSV infections as the season progresses.
Encouragingly, recent advancements in vaccines may provide additional protection. In 2023, new RSV vaccines were licensed for pregnant women and older adults, along with antibody injections for infants. As of October, about 41% of Americans aged 75 and older and 40% of infants have been vaccinated against RSV, according to CDC statistics.
Meanwhile, COVID-19 activity is also low compared to earlier peaks. Recent CDC research indicates that the COVID-19 vaccine remains effective in preventing severe illness in children. Among children aged nine months to four years, the vaccine was found to be 76% effective against severe symptoms requiring emergency care, while effectiveness for older children aged five to seventeen was reported at 56%.
Despite these findings, vaccination rates for the current COVID-19 vaccine are low, with only about 7% of children and 15% of adults having received the latest version. The CDC’s recent decision not to recommend COVID-19 shots for healthy children has sparked debate among health professionals, especially given the disease’s significant impact, contributing to over 1.2 million deaths in the U.S. since the pandemic began.
As health officials navigate this winter virus season, they emphasize the importance of vaccinations and monitoring emerging trends closely, hoping to mitigate potential health impacts as the season unfolds.
