Because there are many strains of flu virus, so unless you have immunity to them all you will catch flu again.
its not completily gone
Because the virus will mutate. When you get the flu more than once each time it is a different virus.
yes and no because if you had the swine flu once and you get vaccinated you propelywont get it again.
If you catch swine flu once, if you catch it again then it won't be as serious.
Yes. Once you have caught swine flu you cannot catch it again.
yes, because the gestation period of the flu virus is usually between 10-14 days.
No a catch isn't an animal or human. Humans can catch the flu and polio. A lot of kids die from polio and the flu.
Yes. You, if you've ever had the flu more than once.
Bronchitis
It is not possible for you to catch the flu through semen.
Aids, swine flu, scarlet fever, cancer, and personally strep throat (it hurts and you can get it more than once).
I dont think you can catch a headache. You can catch flu or a cold which are symptoms of flu or a cold, but you cant just catch a headache.