Flu is rising in central states, and COVID levels are highest but on the decline in southern states.
Researchers saw sustained efficacy against both severe and less severe symptoms.
Flu activity increased in five regions: the Northeast, New England, the Middle Atlantic, the Midwest, and the Central states.
Just over 40% of mothers said their young babies had received Beyfortus, the new RSV antibody vaccine.
Influenza B proportions are rising in regions where flu activity is trending upward.
Preterm infants accounted for 25% of RSV-associated hospitalizations.
Nirsevimab effectiveness was greater than 70% in infants under 9 months.
Influenza B activity is fueling rises in the Midwest and Central regions.
The hospitalization ratio of human rhinovirus to RSV days was 51%.
The FDA expects to make a decision by early June.