Hi Cinthia!
Thank you for your question.
Although I’m not sure, if you wanted to post it in the medical section, I have an interesting option for staying safe, when training indoors:
https://www.phantom-athletics.com/
They also have a special filter for the mask. This way you can train indoors and with others, with less risk of getting infected. And you have the additional benefit of training your respiratory muscles.
stay safe and healthy!
Thomas