Even in normal circumstances, remote teaching is a unique challenge, and the discussion section strategies that may work in an in-person session may not be as effective when carried out online (if they are even possible online). Attempting to prepare and run a discussion section in transitional circumstances (i.e., beginning a class with in-person sections and shifting to remote sections mid-way through) presents an even more unique and distinct set of challenges, especially when brought about by potentially life and world changing events. The following contains general tips for teaching discussion sections in the middle of such circumstances, as well as strategies modified to reflect the sorts of challenges teaching in transitional circumstances can require.
Outside of class and section, be flexible. Transitional circumstances are going to be uniquely stressful for students. Students may be unable to complete assignments or participate in class and section as usual, and they may (understandably and probably correctly) place less priority on class and section work in general. Work with your course head to see what changes can be made to class structures to accommodate students' needs (e.g., change assignment demands, revise or eliminate deadlines, etc.).
Inside of section, be structured. As students face changing and stressful circumstances outside of class and section, they may need more structure in section. You may find it more difficult to carry out less-structured, more conversational discussion sections in online meetings, especially when the class did not begin as an online class. Make sure to explicitly go over discussion section norms, especially those that are specific to your current online discussion format (e.g., audio muting practices, screen sharing norms, etc.). Additionally, consider section strategies that provide inherent discussion scaffolding: i.e., strategies that give students pre-planned, communicated opportunities to speak and listen, as well as narrower, specified discussion topics to focus on. See the Remote Discussions Strategies page for specific suggestions.
Provide additional, varied means of support. Transitional circumstances means students may face new and varied challenges in seeking necessary support. Aside from the obviously impossibility of in-person meetings, students may have to jump all sorts of new hurdles (e.g., different time zones, internet problems, personal concerns, etc.) in order to seek your help. You can eliminate some of these hurdles for them by providing students with a variety of ways to connect with you. Consider offering both scheduled and open online office hours. Moreover, if you are comfortable doing so, consider creating section-specific forums or group chats; this way students can have an additional way of seeking help, one that can feel more informal than sending an email, from you or peers.