The only official rule is that from 3 sick children in the same class it must be closed.
To date (figure from the Ministry of National Education of November 27: out of 11,000 middle and high schools and 66,000 elementary schools, 302 primary classes closed as well as 300 primary schools. There are 222 high school classes and colleagues and 52 establishments of higher education.
Classes or schools must be reopened 7 days after closing.
To catch up with lessons: academie-en-ligne.fr. All courses from CP to terminal online.