A recent study of schoolchildren finds that the youngest students harbor the most germs. Researchers looked at nasal swabs and symptom reports of more than 800 students and staff in Kansas City, Missouri. Kids in pre-kindergarten and elementary school had the highest rates of virus detection compared with older students and staff. The pre-K kids, ages 3 to 5, had the highest rates of actual illness, too. Young children can have up to 10 respiratory viruses as their immune systems are introduced to different infections for the first time. Those viruses include colds, flu and more.

COVID-19 activity is rising in much of the country. Data shows overall respiratory virus spread is very low in the U.S. But COVID-19 is rising in most states, with more people of all ages going to emergency rooms because of it. The stratus variant is most common. It can cause a "razor blade" sore throat and is considered a "variant under monitoring" by the World Health Organization, but it is only marginally better at evading people's immune systems. Flu and RSV activity remain very low. Doctors say hot summer weather can drive people indoors where respiratory viruses like to spread.

COVID-19 activity is rising in much of the country. Data released Friday by federal health officials shows overall respiratory virus spread is low. But COVID-19 is rising in many states in the mid-Atlantic, the South, the southeast and on the West Coast. More people of all ages are going to emergency rooms because of COVID-19. Flu and RSV activity remain very low. Doctors say hot summer weather can drive people indoors where respiratory viruses like to spread.