A5. Because children don’t have immunity to flu since they have not experienced flu. Immunity lasts long so if you experienced flu when you were a child, the immune is memorized until age of 80 or 90.
If so, why do we catch flu every year?
Because flu viruses change their forms so it often happens that the memorized immunity is not useful to the flu viruses.
Q6. What is the reason that it is better to take a flu vaccination?
A6. (This is just information and I'm not recommending to take a vaccination.)
After you have flu, the vaccination prevents the severe condition. Severe condition is that if viruses increase too much in the body, that sometimes leads to pneumonia or brain fever (encephalopathy). Vaccination injects dead viruses. The white blood cells eat them, analyze the information of viruses, bring back to their base which is lymph nodes and hold a strategy meeting to produce the antibody. The produced antibodies flow in the blood vessels patrolling the whole body and beat the found viruses to prevent the increase of the viruses. The antibodies sometimes can’t reach the viruses but prevent the severe condition.
Q7. When you may get flu, why is it better to go see a doctor within 48 hours?
A7. Because the medicine becomes less effective if you take it after 48 hours. The purpose of the medicine is suppressing the increase of viruses. The viruses are the most numerous in 48 to 72 hours. So if the medicine is taken before viruses increase too much, the duration of fever becomes short.
How does the medicine suppress the increase of flu viruses?
The medicine for flu prevents the viruses from moving to the other cells and increasing. The infected cells die and are eaten by a macrophage which is a kind of white blood cells, and new cells are produced where the infected cells are eaten.
Q8. Why is it dangerous that elderly people have flu?
A8. Because elderly people sometimes don’t have fever due to the weakness of the immune system. They don’t have fever sometimes so they don’t notice that they got flu, resulting in severe condition. When flu is going around in winter, if they have symptoms such as joint pain in the whole body with feeling heavy or sore throat, it is possible that they have flu.
Q9. How many days should you stay home after your fever went down?
A9. 2 days after fever went down. Even after the temperature goes down, there are viruses left so it is possible to infect flu to the other people through sneeze or cough.
Q10. How far does sneezing splash a droplet?
(A) Within 6.5 feet (2 m) (B) Within 10 yard (10 m)
A10. (A) Within 6.5 feet.