全球新冠肺炎病毒大流行（COVID-19）足實改變了我們每一個人的生存與生活。以往熟悉的人事物，卻充滿了巨大變化與各種的不確定性。這場危機不會是暫時的情況，經濟、社會、環境等的衝擊，連帶影響的更是遍及到每個教育現場，其中也包括教學場域與方式（如同步線上教學、非同步遠距學習課程，數位學習工具和平台的支援，多樣化混合式的數位學習、資訊安全性和隱私意識提升等）。在面對這波前所未有的全球巨變，教與學的應變力絕對是關鍵。本篇論文因應這場全球化的大挑戰，提出一種漸進式的「COVID-19教學疫苗：21世紀學習的雲端串聯學習課程」。此跨校教學合作計畫乃鏈結台灣及日本兩所語文專業大學，三位教授共同建立一個以英語為主要溝通與目標語言學習的交流平台，促進學生多元文化溝通與思考、提升英文寫作和口語表達能力。此外，該跨校教學合作的機制不僅符合解套COVID-19緊急情況的教學窘境，更跨越傳統語文教學場域，兩校三課程師生共同立足於自主，對等，合作與共好的語言學習環境，透過多元數位學習平台與工具，進行主題意義式對話〔21世紀的21堂課--Harari〕，擁護21世紀全球公民的責任與使命，共同面對未知的挑戰。本跨校串聯學習計畫也運用SAMR（替代，擴充、修正和重新創造）的數位科技學習理論框架（Puentedura，2013），進行該課程活動設計的分析與評估，以求貼近學生的能力與需求，符合教學永續的目標，齊創培育終生學習的個體，應變未知時代的各項挑戰。

The global coronavirus pandemic (COVID-19) has undermined our perspective of the world in substantial and profound ways. The familiar has become unapproachable; the safe seems vulnerable; and certainty has been replaced by unpredictability. This is not going to be a temporary situation. Instead, the impact and implications of this crisis stretch far and wide into every educational sector (streamlining of distance learning, readiness of digital learning tools and platforms, blended approaches for diverse learning needs, and ensuring awareness of data security and privacy) including the higher education system. Amidst a global pandemic which is forcing workplace and educational changes, adaptability is the key. This paper shares a progressive "pedagogical COVID-19 vaccine" characterized by our "Tandem Lessons for the 21st Century Learning" project, an ongoing inter-institutional action research (Two language specialized universities located in Taiwan and Japan) investigating the impact of tandem learning among English as lingua franca (ELF) learners at the tertiary level and in global virtual learning communities. Rather than simply attempting to conduct a language exchange platform, the project investigators/course instructors aim to engage three cohorts of students from different cultures and educational institutions to discuss and review issue-based reading materials drawn from "21 Lessons for the 21st Century" (Harari, 2018) while using their target language, the lingua franca of English to communicate and develop writing and speaking tasks. Complying with the COVID-19 emergencies and school closures, this project is grounded in autonomous, reciprocal, collaborative and cooperative language learning contexts to legitimize learnership, strengthen connection, encourage conversations, and embrace diversity for 21st century global citizenship. In addition to the issue-focused project-based learning, the effective infusion of information technology tools and digital applications have acted like the veins conjoining the process and outcome of this tandem learning project. In other words, the constraints of traditional classroom and foreign language teaching have been unshackled while learning has been enhanced and augmented with the ubiquity and diffusion of digital and information technology (e.g., smartphones, social networking platforms, G-suite for Education, and software applications of multimodal discussion and presentation boards, etc.). This tandem learning project is also evaluated through the lens of the SAMR (Substitution, Augmentation, Modification, and Redefinition) framework (Puentedura, 2013) to reassure quality teaching practices in project/lesson design with the hierarchical integration of digital technology. This SAMR model challenges the language educators to "teach above the line" moving from technology as a means to enhance teaching to an approach that transforms foreign language instruction. Many educators, including the three Tandem Lesson Project instructors across two partner institutions, have made a serious commitment to preparing students for the future by leveraging digital communication technologies. This commitment is guided by the understanding that instructional technology provides a vehicle to support autonomous learning and sustainable pedagogy in the foreign language classroom, both physically and virtually.