caused by influenza viruses. The most common symptoms are chil, fever, runny nose,
sore throat, muscle pain, headache, coughing, weakness/fatigue and discomfort

Cancer is defined as an uncontrolled division or proliferation of cells without any
differentiation. It is a non-infectious disease caused by the agents called carcinogens.

Smallpox is a serious, highly contagious and often life threatening disease
characterised by a rash and (blisters) on the face, arms and legs. It is caused by the
Variola virus. It get transmitted from a person to others by various means like sneeze,
saliva, contaminated body fluids, etc

Allergy is the exaggerated response of the immune system to certain antigens in the
environment (pollen, dust, mites, molds, cloth fibres, animal hair, etc). It occurs due to
the release of chemicals like histamine and serotonin from the mast cells. It is
non-infectious response.