回复 '医者意也' 的评论 : below from CDC(https://www.cdc.gov/flu/about/qa/vaccineeffect.htm)
How effective is the flu vaccine in the elderly?
Older people with weaker immune systems often have a lower protective immune response after flu vaccination compared to younger, healthier people. This can make them more susceptible to the flu. Although immune responses may be lower in the elderly, vaccine effectiveness has been similar in most flu seasons among older adults and those with chronic health conditions compared to younger, healthy adults.
If older people have weaker immune responses to flu vaccination, should they still get vaccinated?
Despite the fact that older adults (65 years of age and older) have weaker immune responses to vaccine flu vaccines, there are many reasons why people in that age group should be vaccinated each year.
First, people aged 65 and older are at increased risk of serious illness, hospitalization and death from the flu.
Second, while the effectiveness of the flu vaccine can be low among older people, there are seasons when significant benefit can be observed. Even if the vaccine provides less protection in older adults than it might in younger people, some protection is better than no protection at all, especially in this high risk group.
Third, flu vaccine may protect against more serious outcomes like hospitalization and death. For example, one study concluded that one death was prevented for every 4,000 people vaccinated against the flu.
In frail elderly adults, hospitalizations can mark the beginning of a significant decline in overall health and mobility, potentially resulting in loss of the ability to live independently or to complete basic activities of daily living. While the protection elderly adults obtain from flu vaccination can vary significantly, a yearly flu vaccination is still the best protection currently available against the flu.
There is some data to suggest that flu vaccination may reduce flu illness severity; so while someone who is vaccinated may still get infected, their illness may be milder.
Fourth, it’s important to remember that people who are 65 and older are a diverse group and often are different from one another in terms of their overall health, level of activity and mobility, and behavior when it comes to seeking medical care. This group includes people who are healthy and active and have responsive immune systems, as well as those who have underlying medical conditions that may weaken their immune system and their bodies’ ability to respond to vaccination. Therefore, when evaluating the benefits of flu vaccination, it is important to look at a broader picture than what one study’s findings can present.
回复 '向往的生活' 的评论 :你查了CDC网站，死亡数字到底是多少？
我说的数字是科学家估算的结果，CDC并没有具体的死亡数据，因为联邦不强制各州上报相关资料，但儿童死亡例外。Anne Schuchat, CDC 执行主任今年2月表示：Deaths from influenza and pneumonia, which are closely tied to each other in the winter months, were responsible for 1 of every 10 deaths last week, and that’s likely to rise. There were 40,414 deaths in the U.S. during the third week of 2018, the most recent data available, and 4,064 were from pneumonia or influenza, according to the CDC data. The number for that week is expected to rise more reports are sent to the agency。一个星期4000多人因流感-肺炎死亡，去年流感死亡人数应该不止8万。
回复 '医者意也' 的评论 : 下面资料来自CDC供你参考：
How many flu-associated deaths occur in people who have been vaccinated?
As previously explained, flu-associated deaths in adults are not a nationally notifiable condition, and so states are not required to report flu-associated deaths in adults to CDC. In contrast, flu-associated deaths in children are a nationally notifiable condition, and so jurisdictions (inclusive of state, city or local public health departments) do provide data to CDC on flu-associated deaths in children. These data generally include demographic information, flu laboratory test results, clinical information, and information on the child’s vaccination history, when it is available. During past seasons, approximately 80% of flu-associated deaths in children have occurred in children who were not vaccinated. Based on available data, this remains true for the 2017-2018 season, as well. For the latest surveillance data on flu deaths in children, see https://gis.cdc.gov/GRASP/Fluview/PedFluDeath.html.