Yes, and some schools explicitly say to describe both positive and negative impacts. Be careful not to come off the wrong way, COVID killed 600k in the US and caused (lifelong/future) grief for many more.
Hi there! Yes, it can. However, you need to be strategic about the information you share in order to maximize your chances of being admitted. An essay where you discuss a challenge that COVID brought to your life and then shows how you were able to overcome said challenge will help you showcase your skills in a much more direct way than simply writing about how covid impacted you positively. The truth is that COVID was hard on almost everyone, so there must be something you can talk about in that regard. Of course in the end you always want to show what you learned and show your resilience and determination and bring it to a positive, but your narrative should show progression and a learning process, as this will help the committee see that you have what it takes to navigate the rigor of med school. In sum, your essay should be positive, but this should be the end result of a process of determination, self-discovery, and adaptability. Hope this helps and best of luck!