Top ten factors that affect the immune system (COVID-19, Boost your immunity - Part - 3)

For the immune system to work at its highest potential, two things are very important. To refrain from everything that destroys the immune system and to embrace everything that strengthens it.
Let's identify those top 10 factors that affect the immune system.
If you haven’t watched the previous video in which we discussed the 1st and the second line of defence. -
COVID-19, Boost your immunity - Part - 1 link - https://youtu.be/OmhfrnDiitg
COVID-19, Boost your immunity - Part - 2 link https://youtu.be/TVxMOi9Sa_Q