緊急授權適用緊急標準？ ——以美國COVID-19期間疫苗緊急授權為例

Abstract

本文研究主題為美國緊急授權制度下審查COVID-19疫苗的「緊急標準」，分析在緊急狀態下，美國是否採取了相較於平常時期更低的標準審酌科學證據。為了解美國食品藥物管理署（下稱食藥署）在不同情形下採擇科學證據的標準，本文首先檢視新藥審查中採用的多種加速機制，並以兩個具指標性的新藥：新型口服抗凝血劑以及C肝藥物作為分析個案，發現經歷過去二十年的修法以及資源投注，美國食藥署流暢、有系統地運用彈性的試驗設計、解讀試驗結果。相較之下，疫苗的發展與審查涉及較為複雜的試驗設計與執行考量，並且需要更為謹慎地處理安全性審查。Agriflu以及Flublok兩支流感疫苗分別使用已知技術與新技術研發，二者的上市審查則呈現美國食藥署雖然高度仰賴指引文件設定的標準，但也並非毫無彈性。最後，在COVID-19疫情的緊急狀態之下，美國食藥署運用指引以及高密度的對話溝通平順地作成了兼顧公共衛生目的的緊急授權決策。與美國相較，台灣食藥署對本土疫苗的審查受到地緣政治特性、欠缺大規模疫情以及資訊揭露不足等多重因素的影響。綜觀美國食藥署藥物、疫苗上市審查的軌跡，其在COVID-19疫情下所為的科學證據評價，立基於其過往多年累積的審查架構但不失彈性，同時也仍維持一定程度的資訊揭露，在政治性決策與科學證據採擇間取得平衡。

This thesis aims to understand what constituted the “emergency standards” for the COVID-19 vaccine under US Emergency Use Authorizations (EUAs), in particular whether the standards for evaluating scientific evidence were lowered compared to that under normal conditions. To gain a basic understanding of US Food and Drug Administration (FDA) assessment of scientific evidence under different circumstances, this thesis begins with an examination of expedited pathways for new drug approvals, using dabigatran and sofosbuvir, two landmark new drugs to demonstrate approval metrics. With updated legislation and increased resources in the past two decades, the US FDA is able to apply flexible standards for trial design and allow extrapolations of trial data in an organized and streamlined fashion. However, vaccine development and approval involved more complex trial design and implementation considerations, as well as greater attention to safety issues. The approval of two influenza seasonal vaccines Agriflu and Flublok, the former utilizing a well-known technique and the latter a novel technique, showed that the US FDA relied heavily on guidance documents for standard setting but were still subject to uncertainty. Finally, in the COVID-19 public health emergency, the US FDA utilized guidance documents and intense communication to conduct a smooth review process that reflected the political considerations during the pandemic. In comparison, Taiwan FDA’s approval of domestic vaccines was complicated by local concerns, including geopolitical issues, lack of infections and transparency. This thesis concludes that the evaluation of scientific evidence in US COVID-19 vaccine EUAs references the past, maintains resilience, and demonstrates adequate transparency, reflecting its political nature.