Two new studies, one based on households in southeast Michigan and one involving hospitalized Japanese adults, compare respiratory syncytial virus (RSV) to seasonal flu and describe co-infection dynamics between the common and transmissible respiratory viruses and how they differ in disease severity.

During the COVID pandemic, RSV showed a slightly odd pattern: like flu, it basically disappeared in the 2020–2021 season, likely because of masking and social distancing. But in 2022–2023 it came roaring back and had a large, early peak during the fall. Last year saw a significant surge as well, but it was closer to the timing of a typical season.

Just over a month into the new year, influenza season is hitting hard in the Southland, and the flu isn't the only virus making a strong showing.

It feels like everyone is sick right now. And while that is a slight exaggeration, the real situation isn't too sunny either.

Like clockwork, flu viruses seem to strike more people in winter than in any other season—and there are several reasons for that.

Fact checked by Nick Blackmer Despite a temporary freeze on public communications, the Centers for Disease Control and Prevention (CDC) still released weekly updates on respiratory illnesses. Cases of respiratory syncytial virus (RSV) have peaked and are beginning to decline in many areas of the United States,