DID you get a flu shot this year? For the first time, the Centers for Disease Control and Prevention in the US is recommending that all children aged from 6 months to 18 years receive the flu vaccine．
Vaccines battle diseases caused by bacteria and viruses．A weakened form of the germ （微生物） is introduced into the body．The body makes special substances called antibodies to fight the germs．If the actual germs were to attack, the antibodies would fight it．
Because there are many kinds of flu viruses, scientists must create a new vaccine formula （方程式） each year．Researchers must make a prediction．
It is like forecasting the weather．Sometimes they are right on, and sometimes they are off．But even when the vaccine does not closely match circulating flu types, it can make the illness less serious．
"The flu vaccine is not as effective as the polio （小儿麻痹症） vaccine or the measles vaccine," says Dr William Schaffner of Vanderbilt University School of Medicine．"It's not a great vaccine, but it is quite a good vaccine．"
But a flu vaccine doesn't work for everyone．There are certain people who should be careful about taking it．
Because the vaccine is produced in eggs, those who are allergic （过敏的） to eggs should not take it．If you have a fever, you should wait until you recover．
Some people are afraid that they might get the flu from the flu shot．Scientists say that it is not possible, because the viruses in the flu shot are inactivated．But some minor side effects such as low-grade fever and body ache could occur．If they do, they begin soon after the shot and usually last only one to two days．
Did you know?
Smallpox was the first disease people tried to prevent by putting a virus into a healthy person．In 1796, English scientist Edward Jenner placed some infected material under a boy's skin．
64．By saying "It's not a great vaccine, but it is quite a good vaccine", the author means the flu vaccine ．
A．does help to make illness less serious
B．is not effective, compared with the polio and measles vaccines
C．is not as effective as the polio and measles vaccines
D．is quite good because it works for everyone
65．We can infer from the passage that ．
A．those who are allergic to eggs should not take flu vaccine
B．you should go to a doctor if you have a fever or body ache after taking the flu vaccine
C．all the flu vaccines are not effective for everyone
D．it is possible that some people might get the flu from the flu shot
66．It is not advisable for everyone to take flu vaccine because ．
A．there are many kinds of virus
B．the flu vaccine is not as effective as the polio and measles vaccines
C．it has some minor side-effects
D．someone may be allergic to it
67．What topic will be discussed in the following paragraph?
A．How the smallpox vaccine worked on the boy．
B．The side-effects of smallpox vaccine．
C．The origin of the flu vaccine．
D．What kind of people should be careful about taking smallpox vaccine．