The influenza virus has finally returned in earnest. Flu season activity is high throughout the U.S., and experts expect many more cases and hospitalizations to occur in the weeks ahead. One bright spot is that this year’s vaccines appear to be well-tuned to the currently circulating flu strains, so they should provide valuable protection against the viral infection.
On Monday, the Centers for Disease Control and Prevention released the latest weekly findings from its routine flu surveillance program, which keeps track of both flu-related hospitalizations and outpatient visits for flu-like illness.
Based on this data, flu activity is high to very high in 35 states and territories, especially in the eastern and southern regions of the country. The cumulative hospitalization rate at this point in the year (week 46) is also the highest it’s been since the 2010-2011 flu season. Overall, the CDC estimates that there have been at least 6.2 million illnesses, 53,000 hospitalizations, and 2,900 deaths from flu since October, including 12 confirmed pediatric deaths. And with much of the holidays still left to enjoy, these case numbers will only go higher.
“We are likely to see an increase in the upcoming weeks,” Lynnette Brammer, an epidemiologist and leader of the CDC’s influenza surveillance team, told NBC News.
Since the arrival of covid-19 in late 2019, the flu has become much less common. The flu was basically non-existent during the 2020 to 2021 winter, while last winter’s flu season was weird but still far milder than usual. There are likely several reasons why a supposed “twindemic” featuring the flu and covid-19 never came to pass, including recent speculation that respiratory viruses in general tend to crowd each other out. But a major factor behind its disappearance is believed to be the physical distancing precautions that were enforced or voluntarily taken by many people to limit the spread of covid, which may have worked even better to prevent less contagious diseases like the flu. These precautions have largely waned, and in turn, many garden variety infections have returned.
For instance, the U.S. has seen a more severe and earlier-than-usual peak in infections from the respiratory syncytial virus, or RSV, this year. RSV typically causes a mild cold in most, but it can be life-threatening for young children and older people. As a result of the surge, many children’s hospitals have reported much higher levels of RSV-related hospitalizations than even those seen during the normal RSV season. There is some speculation that infection by covid-19 has weakened children’s immune systems, making them more vulnerable to severe RSV, but many experts argue that the decline of population immunity alone is enough to explain these surges.
Thankfully, cases of RSV do now appear to be slowing down in the U.S. And while many people are still getting sick and dying from covid-19, the threat of a massive surge arriving this winter as it has in the past remains low for the time being. We may even get relatively lucky with the flu, since this year’s vaccine matches up well to the majority of circulating strains of influenza, according to the CDC.
Of course, just because this winter won’t be as bad as recent ones when it comes to respiratory illness doesn’t mean we should neglect sensible precautions. Getting your updated covid-19 booster and annual flu shot will lower your risk of snot-related misery and severe complications this holiday season, and other measures like staying home when sick or wearing masks in high-risk situations can help limit the spread of flu, covid-19, RSV, and other germs.