 U.S. government officials have been especially concerned about schools because the H1N1 flu virus appears to disproportionately affect young and school @-@ age people , between six months and 24 years of age . The H1N1 outbreak led to numerous precautionary school closures in some areas . Rather than closing schools , the CDC recommended that students and school workers with flu symptoms should stay home for either seven days total , or until 24 hours after symptoms subsided , whichever was longer . The CDC also recommended that colleges should consider suspending fall 2009 classes if the virus began to cause severe illness in a significantly larger share of students than the previous spring . They also urged schools to suspend rules , such as penalties for late papers or missed classes or requirements for a doctor 's note , to enforce " self @-@ isolation " and prevent students from venturing out while ill ; schools were advised to set aside a room for people developing flu @-@ like symptoms while they waited to go home and to have ill students or staff and those caring for them use face masks . 
