This year’s flu season is shaping up to be a bad one. The new type of flu virus is more severe than most. In addition many people find the vaccine this year to be less effective, and others are wondering if they should still get a flu shot. The answer is yes.
Each summer, scientists try to make a best guess on which variants (变体) are going to be more common in the coming year. They look at data from other countries, and then they make the shot to match.
Sometimes a vaccine doesn’t work well because some variants change too much. That’s why in any year, even when you’re vaccinated, you can get the flu. The shot is about reducing your risk, not getting rid of it.
“Less” and “more” effective are relative terms, so we need to focus more on absolute risks. In 2010, researchers published an in-depth analysis of all flu shot studies. They showed that when a vaccine was considered effective, 1.2% of vaccinated people had the flu, while 3.9% of unvaccinated people had the flu. That’s an absolute risk reduction (ARR) of 2.7 percentage points. In studies in which the flu shot was considered ineffective, 1.1% of vaccinated people had the flu compared with 2.4% of unvaccinated people. The ARR was 1.3% points.
Let’s say this year’s flu vaccine is even worse than we think. Maybe the ARR will be as low as 1 percentage point. That’s still not that bad. Given the millions who are likely to suffer from flu and the thousands of deaths each year, this is a big payoff in public health. The Centers for Disease Control and Prevention (CDC) says that 9 million to 36 million people become ill with the flu each year in the United States. Somewhere between 140,000 and 710,000 of them require hospitalization, and 12,000 to 56,000 die each year.
No vaccine is perfectly protective in any year. But to minimize your chances of illness, yes, you should still get the flu shot this year, and any year.
4. What is the paragraph2 mainly about?
A.Why some vaccines are ineffective. | B.Why people should get vaccines. |
C.How a new vaccine is developed. | D.How people survive flu in summer. |
5. What can the ARR tell us according to the text?
A.How dangerous flu could be. |
B.The risk of a vaccine. |
C.How flu spreads. |
D.The effectiveness of a flu vaccine. |
6. Why does the author provide the CDC’s figures?
A.To show many people suffer from serious diseases each year. |
B.To show flu vaccines are sometimes ineffective. |
C.To show flu is a major cause of human death. |
D.To show vaccines can still save many people. |
7. What is the main purpose of the text?
A.To report a threatening type of flu virus. |
B.To persuade people to receive flu vaccines. |
C.To explain the spread of flu viruses. |
D.To give an introduction to this year’s vaccine. |