Vaccination(接种疫苗)is among the most effective ways to help us prevent diseases. For viruses that don't change too much-the measles virus(麻疹病毒), for example—getting vaccinated is a once-and-for-all method to prevent you from becoming infected with the virus. If you had two measles vaccines when you were a child, you will be protected for life.
However, it's a different story when it comes to influenza(流行性感冒), commonly known as "the flu", which generally peaks between December and February. Flu vaccines cannot protect us in the long term.
There is no long-term immunity(免疫), according to Theodore Strange, associate medical director at Staten Island University Hospital in New York. "The virus essentially 'changes its coat'—HIN1, H2N3, and so on," he told the website Healthline.
Apart from a person's immune protection from flu vaccination declining over time, flu viruses are also constantly changing. So the vaccines are likely to be updated from one season to the next to protect against the viruses that research suggests may be the most common during the upcoming flu season.
Thus, to develop effective flu vaccines, over 100 national influenza centers around the world conduct year-round surveillance(监测)for influenza. Researchers will test thousands of influenza virus samples from patients, according to the official website of the US Centers for Disease Control and Prevention(CDC). The World Health Organization also suggests there are three or four influenza viruses that are most likely to spread among people during the upcoming flu season.
But even when a vaccine is developed, getting it can prove to be difficult, as it is in high demand and short supply. The timing of influenza vaccine production and distribution is unpredictable, thus the availability of the flu vaccine supply does not always coincide with(与……一致)peak demand.
So scientists prioritize(划分优先顺序)access to the vaccination. The CDC recommends key populations, such as medical staff, teachers, students, children and those aged 60 and above, receive flu vaccines.
This year the situation seems more complicated, as the upcoming flu season coincides with the COVID-19 pandemic. This could overwhelm hospitals, straining(过度使用)resources and healthcare workers' time.
8. What do we know about influenza?
A.Influenza viruses are continuously changing. |
B.It commonly peaks between November and December. |
C.Getting two flu vaccines can protect people against the viruses. |
D.HINI and H2N3 are the most easily infectious flu viruses. |
9. What do researchers do in order to develop effective flu vaccines?
A.They update vaccines once a year. |
B.They monitor the flu throughout the year. |
C.They focus on one or two viruses during a period. |
D.Influenza centers worldwide share virus samples from patients. |
10. Why do scientists prioritize access to the vaccination?
A.Because not all people can afford it. |
B.Because some people refuse to get vaccinated. |
C.Because the vaccine is not safe for everyone. |
D.Because the vaccine doesn't always meet the demand. |
11. What does the author think of the upcoming flu season?
A.It could be more challenging than ever for medical workers. |
B.Enough resources have been prepared to cope with it. |
C.Flu vaccines will be provided for the public in November. |
D.The flu vaccines are expected to help prevent COVID-19. |