Winter Viruses: Flu, RSV, and COVID-19 – What to Expect This Season
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Despite widespread sniffles and coughs, flu activity remains low across much of the U.S., though experts are closely monitoring several respiratory viruses poised to peak this winter. New government data released Friday indicates high flu activity in only four states – Colorado, Louisiana, New Jersey, and New York – with most others reporting minimal or low levels. While severity indicators are increasing, officials at the U.S. Centers for Disease Control and Prevention (CDC) maintain that the season is currently within “mild” parameters.
The winter months traditionally see a surge in respiratory illnesses due to increased indoor gatherings, facilitating the spread of germs. Beyond the common cold and influenza, norovirus – a highly contagious cause of vomiting and diarrhea – is also on the rise, with cases trending upward over the past month.
Flu Season: A Potential Threat Looms
Experts are particularly focused on the flu, remembering last season’s severity. The overall flu hospitalization rate reached its highest level in 15 years, since the H1N1 pandemic, and tragically, 288 children succumbed to the virus – matching the death toll of the 2009-2010 pandemic and representing the worst recorded for a regular U.S. flu season. The first pediatric flu death of the current season was reported this week, raising concerns.
A particularly worrisome development is the prevalence of the A H3N2 virus, historically associated with more severe illness and higher hospitalization rates among older adults. Currently, H3N2 is the dominant strain being reported. Even more concerning, analysis reveals that 89% of analyzed H3N2 infections are a new variant – known as the subclade K – that significantly differs from the strain included in this year’s flu vaccines.
While flu seasons typically peak around February, it remains too early to fully assess the impact of this vaccine mismatch. The CDC continues to recommend annual vaccination for everyone 6 months and older, emphasizing that it’s not too late to get protected. Current vaccination rates stand at 42% for U.S. adults and 41% for children, according to CDC data. Preliminary analysis from the U.K. suggests that this year’s flu shot, while not preventing all infections, can still significantly reduce the severity of illness.
RSV: A Late-Season Start, But Still a Concern
Respiratory syncytial virus (RSV), a common cause of cold-like symptoms, poses a significant threat to infants and the elderly, often overwhelming hospitals with cases of wheezing babies during the fall and winter. While RSV seasons typically peak in December or January, the current season appears to be starting later than usual, with reported cases remaining relatively low according to the CDC.
However, experts anticipate an increase in RSV cases. “It’s likely more RSV is coming,” stated Dr. Cameron Wolfe, an infectious diseases expert at Duke University, in an email. Friday’s CDC update confirmed this, showing rising infections in the South and mid-Atlantic states.
The outlook isn’t entirely bleak, however. The recent licensing of new RSV vaccines for pregnant women and older adults, along with antibody injections for infants, offers a potential shield. “Perhaps, glass half full, we’re cumulatively getting more people slowly vaccinated against RSV,” Wolfe said. “And because the virus mutates far less quickly than flu or COVID, the one vaccine you might have had as an older adult two or three years ago is likely still quite effective.” As of October, approximately 41% of Americans aged 75 and older and 40% of infants have received RSV protection, according to CDC data.
Notably, the Trump administration recently initiated a review of the two injectable drugs used to protect babies and toddlers, despite a lack of reported safety concerns, raising questions about potential political influences on public health measures.
COVID-19: Activity Remains Low, But Vigilance is Key
Currently, COVID-19 activity is relatively low. Recent CDC research demonstrates the effectiveness of the COVID-19 vaccine in preventing severe illness in children. The shots were found to be 76% effective against symptoms severe enough to require a hospital visit or urgent care for children aged nine months to four years, and 56% effective for those aged five to 17 years.
Despite these findings, vaccination rates remain low, with only 7% of children and 15% of adults receiving this season’s updated COVID-19 vaccine. This comes after previous recommendations from Trump administration officials to halt COVID-19 vaccine recommendations for healthy children, and ongoing efforts by anti-vaccine advocates to revoke licenses for Moderna and Pfizer-BioNTech vaccines.
In October, the CDC shifted its guidance, leaving COVID-19 vaccination decisions to individual patients, a move criticized by several doctors’ groups and scientific organizations who argued against weakening recommendations for a disease responsible for over 1.2 million U.S. deaths.
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