In the small phase 1 study, children received a single dose of the live attenuated nasal vaccine.
The rates the researchers saw could serve as a baseline for gauging whether coinfections rates are shrinking or growing.
Twelve fur farms in Finland have now been affected by H5N1 avian flu outbreaks.
The drug is indicated for babies entering their first RSV season and for kids up to 2 years old who remain vulnerable in their second season.
The recommendation stipulates that people can get a single dose of the vaccine based on shared clinical decision making, meaning it isn't recommended for everyone in the age group.
ACIP recommends newly approved RSV vaccines for use in two older age-groups, people ages 60 to 64 and those ages 65 and older.
The FDA antimicrobial drugs advisory committee unanimously recommended nirsevimab for preventing respiratory syncytial virus in infants during their first RSV season.
Flu and RSV levels are rising to prepandemic levels, with increasing hospitalizations in children younger than 2 years.
The approval gives the nation two RSV vaccine options for use in adults 60 and older.
Though the group was impressed with the efficacy of the vaccine, they wanted to know more about preterm births, a factor that stalled a similar vaccine.
