從這段開始看
（這段+Ongoing那段）
Furthermore, both trials were largely conducted before the severe acute respir
atory syndrome coronavirus 2 (SARS-CoV-2) variant B.1.1.7 became dominant in t
he United Kingdom9.
以下提到一些疫苗對於B.1.1.7的防護力（文獻15、16、18、19等）
其中16直接指出 BNT 非常推薦使用在英國變種上
所以這篇文獻的下一段才提出對上面文獻的質疑
However, existing studies have either investigated defined sub-populations9,18
,19 or have relied on the results from symptomatic testing programs15,17, pote
ntially leading to bias from vaccination status influencing the test-seeking b
ehavior of cases not requiring health care
他認為這些文獻選用的都已經是有症狀者或特定的子群體，所以會造成結果的偏差
基本上你選讀的這篇「主要目的」是為AZ效力較差做翻案
沒說他結論錯，但這篇的存在也說明「在主流研究中」BNT效力確實較佳
至於兩者真實效力如何
反正你選讀了這篇
我以這樣的內容回應你
基本上就注定我們的看法不同了
而我確實與這篇提到的部分文獻看法一樣
BNT比AZ更適合作為對變種的疫苗
就舉本篇第16號參考文獻內容
BNT162b2 vaccine to be 70% 21 days after the first dose, increasing to 85% 7 d
ays after the second dose in our study population. Given the dominance of the
B.1.1.7 variant in England during the study period, which accounted for 50% or
more positive tests in Pillar 2 laboratories since the beginning of December,
2020, in the South East, London, and East of England, and in all regions by e
arly January 2021 (with Yorkshire and the Humber the last region), our finding
s suggest that the BNT162b2 is effective against the B1.1.7.16
我再舉第19篇，針對80歲以上老人的文獻結論也是BNT較佳
BNT
From 14 days after the second dose a vaccination effectiveness of 89% (85% to
93%) was found compared with the increased baseline risk
AZ
With ChAdOx1-S, effects were seen from 14 to 20 days after vaccination, reachi
ng an effectiveness of 60% (41% to 73%) from 28 to 34 days, increasing to 73%(
27% to 90%) from day 35 onwards.
以上
為避免斷章取義，我盡量引用原文。