Swine flu, caused by the H1N1 virus, is a contagious respiratory disease that can spread from human to human, leading to severe symptoms similar to seasonal flu. While no vaccine is currently available, antiviral medications like oseltamivir and zanamivir can help treat the infection, and practicing good hygiene, such as hand washing, is key to preventing transmission. Those with flu-like symptoms should avoid close contact with others and seek medical attention if experiencing severe symptoms.