Who should be treated with antiviral therapy? General adult patients Adult patients with laboratory pathogenetic confirmation or high suspicion of influenza and risk factors for complications should be treated within 48 hours of onset of illness, regardless of underlying disease, influenza vaccine immunization status, and severity of influenza illness. Antiviral medications are also recommended for adults who require hospitalization and whose specimens test positive for influenza virus after 48 hours of illness onset. Infants and young children are more likely than adults to develop laryngitis, bronchitis, pneumonia and other infections, so antiviral treatment should be given as early as possible, with different dosages but the same course of treatment as for adults. Elderly patients Elderly patients are often co-morbid, and the elderly are often accompanied by respiratory system, cardiovascular system and other underlying diseases. As a result, patients’ conditions tend to be more severe and progress more rapidly, with a high incidence of pneumonia. Therefore, antiviral therapy should be started as early as possible when influenza is diagnosed or suspected in the elderly. Critically ill patients For critically ill patients, patients with complications or disease progression, high-risk patients, and hospitalized patients, initiating antiviral therapy within 48 h of the onset of influenza symptoms is of greatest benefit. Oral oseltamivir or intravenous palamivir is recommended for hospitalized patients with severe illness or complications of other diseases. In addition to this there are patients in pregnancy and 2 weeks postpartum who need to be given prompt antiviral therapy. This may turn many people’s preconceived notions upside down. In fact, failure to administer antiviral therapy within 2d in pregnant women is associated with a significant increase in mortality. Conversely, there is no evidence that administration of antiviral therapy (oseltamivir or zanamivir) results in adverse pregnancy outcomes such as fetal malformations, preterm labor, and low birth weight. Neuraminidase inhibitors The mechanism of action of neuraminidase inhibitors is to prevent the virus from being released from infected cells and invading neighboring cells, and in this way reduce the replication of the virus in the body, and they are active against both influenza A and B. There are two varieties of neuraminidase inhibitors available in China: oseltamivir and zanamivir.