What are two illnesses in humans caused by viruses?

1. Common Cold: The common cold is a mild respiratory illness caused by various virus families, including rhinoviruses, coronaviruses, and adenoviruses. It spreads through contact with respiratory droplets or contaminated objects. Symptoms include a runny nose, sore throat, sneezing, and mild cough.

2. Influenza (Flu): Influenza, commonly known as the flu, is a respiratory illness caused by influenza viruses. It is highly contagious and can spread rapidly through communities, especially during flu seasons. Symptoms may include fever, chills, muscle aches, sore throat, cough, headache, and fatigue.