Could be that he's saying that - for your sister in law - since she'd already gotten COVID severely, a vaccine wouldn't be helpful. Just google "deathbed covid patient vaccine" to see that dying people ask for the vaccine, only for their doctors to tell them "yeah it's too late for that".what logic is BS , are you saying the antibodies used to treat my sister in law and cure her are false ?
But, I guess natural antibodies can help active COIVD patients based on what you're saying? That's great for your SIL and I hope she recovers. The vaccine likely would have prevented her from getting into that state, but - once in said bad state - the vaccine can't really help at all. It's not a cure. it's a preventative measure.