By C-19, do you mean Covid-19 injection? Haven't had any injections in years(didn't even take covid vaccine since most people here faked their sickness to get free care from government at that time or so I was told), except during a blood test for some school stuff. Hmm, does oxygen really have any effect on cancer? I'm just hearing that... although I seriously hope someone finds a solution, may that misfortune not befall any of our families😔