What are the non-infectious causes of diseases?

During a health check-up camp in a school, the doctor talked about the prevention of diseases. Which six points will you share with your friend on the topic "prevention of diseases is more desirable than their successful treatment"?

How are signs of a disease different from symptoms of a disease?

$(a)$ State the principle of immunisation. Name two diseases for which vaccines are available.
$(b)$ Mention two basic principles of prevention of infectious diseases.

Study the given chart carefully and fill in the blanks $(a)$,$(b)$,and $(c)$:

$S$.No.	Name of the disease	Causative organism	Mode of transmission
$1$. Polio	$(a)$	Infection of virus directly/orally
$2$. $(b)$	Lyssa virus	Virus enters human body with saliva of an infected animal
$3$. Typhoid	Salmonella typhi	$(c)$

Educating parents would help a lot in reducing the incidences of diseases in children. Justify the statement with five reasons.