are more susceptible to HCoV-NL63. These populations include children under the age of 5, the elderly, and immunocompromised individuals. The virus seems to have seasonal incidence, occurring most frequently in the winter months in temperate climates. In more extreme and tropical climates the virus has no preference toward a particular season. Many studies have reported the co-occurrence of HCoV-NL63 with other human coronavirus, Influenza A virus, Human orthopneumovirus (RSV), parainfluenza virus, and Human metapneumovirus (hMPV). Transmission As HCoV-NL63 infects the respiratory tract it must be inhaled to get there, and is therefore transmitted by the airborne route. The virus is able to survive for up to seven days in respiratory secretions and remains infectious at room temperature. Once the virus has entered the host, it binds to cellular receptors via its spike proteins. The virus is able to use Angiotensin-converting enzyme 2 (ACE2) as an entry receptor to bind to and enter target cells. Diagnosis It is difficult to distinguish between symptoms caused by infection of the HCoV-NL63 virus and those caused by other common human viruses, making diagnosis and detection complex. Reverse transcription polymerase chain reaction of samples collected through nasopharyngeal swab is the most commonly used method for detection of the virus. Viral culture or blood serum testing for antibodies may also be used for the confirmation of infection. Prevention The United States Centers for Disease Control and Prevention (CDC) recommends several measures for the prevention of infection with HCoV-NL63 including: washing hands often with soap and water, avoiding close contact with sick individuals, and not touching the eyes, mouth, or nose. Treatment and prognosis Treatment for the HCoV-NL63 virus is dependent on the severity of associated symptomology. Most mild to moderate infections will go away on their own. Symptoms can be relieved by taking a pain reliever or fever medication, taking a hot shower, or using a humidifier. Antiviral treatment may be necessary for infected patients that end up in the intensive care unit (ICU) due to acute respiratory infection. Intravenous immunoglobulin is an FDA approved HCoV-NL63 inhibitor that is also used to treat primary immune deficiency, RSV, and Kawasaki disease. Virology HCoV-NL63 is one of seven known coronaviruses to infect humans. The other six are: Human coronavirus 229E (HCoV-229E) Human coronavirus OC43 (HCoV-OC43) Human coronavirus HKU1 (HCoV-HKU1) Middle East respiratory syndrome-related coronavirus (MERS-CoV) Severe acute respiratory syndrome coronavirus (SARS-CoV-1) Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)