1. 流感也挺邪乎的，每年死不少人，別不當回事兒
https://www.cdc.gov/flu/about/burden/2018-2019.html
CDC estimates that the burden of illness during the 2018–2019 season included an estimated 35.5 million people getting sick with influenza, 16.5 million people going to a health care provider for their illness, 490,600 hospitalizations, and 34,200 deaths from influenza
2. 新冠更曆害，病死率是流感的三、四十倍。一旦染上，有3%機率見上帝。
Mortality for COVID-19 appears higher than for influenza, especially seasonal influenza. While the true mortality of COVID-19 will take some time to fully understand, the data we have so far indicate that the crude mortality ratio (the number of reported deaths divided by the reported cases) is between 3-4%, the infection mortality rate (the number of reported deaths divided by the number of infections) will be lower. For seasonal influenza, mortality is usually well below 0.1%. However, mortality is to a large extent determined by access to and quality of health care.
3. 盡管還沒有國家層麵的數據，某些地區的疫情數據也能看出趨勢
Two hundred of the more than 375,000 D.C. residents who are fully vaccinated against the coronavirus have tested positive for the coronavirus and four have died, according to a dashboard District officials unveiled Thursday.
The four fully vaccinated people who died of covid-19 had significant medical histories, and three of them were over the age of 65, Ankoor Shah, head of the city’s vaccine program, said Thursday. Of the 200 breakthrough cases, 57 percent had symptoms, 28.5 percent were asymptomatic. (For 14.5 percent, symptom status was not known.) Thirteen people were hospitalized with covid-19, or 6.5 percent of the breakthrough cases.
........
Just 0.05 percent of the people who were fully vaccinated with the Pfizer-BioNTech vaccine tested positive, compared with 0.04 percent of those who received the Moderna vaccine and 0.12 percent of those who got the Johnson & Johnson shot.
按上麵報道中的數字，
患病率為：(200 x 0.57)/375000 = 0.032% （有症狀的才算病人），非常接近疫苗公司的數據。
住院率為 13/（200 x 0.57) = 11.4%
病死率為 4/（200 x 0.57) = 3.5%
另一地區的數據
https://fox17.com/news/local/24-fully-vaccinated-people-have-died-in-tennessee-health-department-says-breakthrough-case-virus-coronavirus-
The Tennessee Department of Health reports 27 fully vaccinated people have died from COVID-19.
These are among the state's more than 1,000 "breakthrough" cases. These are cases in which fully vaccinated people have contracted the virus.
Data is sent to the Centers for Disease Control and Prevention (CDC). TDH Commissioner Dr. Lisa Piercey said Friday more than two dozen deaths since May 1 and 195 hospitalizations are among breakthrough cases. Including dates before May 1, there have been more than 1,000 breakthrough COVID-19 cases, the state reports.
(so, hospitalization : 195/1000 = 19.5%
and mortality : 27/1000 = 2.7%
It means that the similar rates are observed in 'breakthrough' cases as those not vaccinated.
上麵二地區數據提示：
1. 疫苗（美國用的）可以大大減少發病率，是疫苗的保護性效果。
2. 一旦染病，住院、病死的機會與沒打疫苗的病患差不多。所謂疫苗“防轉重”、“防死亡”之說，需進一步觀察考證。
