When the flu season begins during the late fall of each year, you may hear doctors or health officials remind the public to get their annual flu shots. However, many people have asked, ¡§If the vaccine is effective, then why do people need a new one each year?¡¨
According to medical experts, people need a yearly flu shot because the virus that causes the flu is constantly evolving. The virus, known as influenza, can cause a wide range of uncomfortable symptoms, from a mild sore throat to severe muscle pains. For some demographics, such as the elderly or the overweight, getting sick with the flu can be deadly.
Since the outer structure of the influenza virus changes all the time, epidemiologists must work hard to develop new vaccines based on new strains of the virus in order for them to be effective. At influenza surveillance centers around the world, new strains of the virus are reported and analyzed each year. Around February, the World Health Organization (WHO) decides which of these strains are most likely to be prominent in the coming year. Scientists then get to work to produce a new vaccine before the next flu season arrives.
It¡¦s also important to remember that the body¡¦s immune system is constantly developing as well; it¡¦s not just the influenza virus that is changing. That means a vaccine that might have been effective last year is likely to be useless after 12 months. That¡¦s why experts recommend getting a new flu shot yearly to protect yourself and others. Remember: the vaccines not only alleviate the worst symptoms of the virus but also help reduce transmission of the viral disease throughout the population.
1. According to the passage, when are people most likely asked to get flu shots?
(A) Around February. (B) During the summer season. (C) Near the end of autumn. (D) In the middle of winter.
2. What is the main reason doctors recommend the public get flu shots every year?
(A) The quality of vaccines improves every year.
(B) The vaccines alter the outer structure of the flu virus.
(C) The body¡¦s immune system reduces the effectiveness.
(D) The strains of the flu virus circulating each year are different.
3. Which of the following statements is true?
(A) People with obesity should avoid getting flu shots.
(B) Old vaccines don¡¦t work as effectively as new ones.
(C) Scientists work on new flu vaccines before February.
(D) The WHO is in charge of reporting and analyzing virus strains.
¡´
recommend V-ing «Øij°µ⋯⋯
The doctor recommended relying less on over-the-counter medicine.
Âå®v«Øij¤Ö¨Ì¿à¦¨ÃÄ¡C
¡´
might have+ ¹L¥h¤Àµü ·í®É¥i¯à¡þ¤]³\·|⋯⋯¡]ªí¹ï¹L¥hªº±À´ú¡^
If Larry hadn¡¦t run upstairs to save his dog, he might have been one of the survivors.
n¬O¿à·ç·í®É¨S½Ä¤W¼Ó¥h±Ï¥Lªºª¯¡A¥L¥i¯à·|¬O¨ä¤¤¤@¦WƦsªÌ¡C
More to Learn
overweight [ £¿ovɚ͵wet ] a. ¶W/¹L«ªº¡AªÎDªº
• Bruce is seriously overweight because he always has fried chicken and hamburgers for dinner.