Right, I'd have to watch it again to find out the context of that statement, and I will and let you know what I think. I will say that for example in Ontario where I live where there's been just over 10,000 deaths there's been 7 deaths for people under 19. Yeah, March 2020 wouldn't be the Alpha, that didn't show up until around Sept 2020 and around Dec.2020 in the US so it was probably the early Wuhan variant, which was the variant that the vaccines were originally meant to manage.
Think of antibodies as front line soldiers who attach the initial infection and regardless of whether a person was naturally infected or was vaccinated these are going to wane naturally, that is what happens naturally. The reason antibodies wane is because it can effect the bloods viscosity and cause lots of problems and even death, so the body protects itself and slowly removes the antibodies from our system, this is just a basic description of what happens.
So now what happens is the virus enters our nasal passages and we become re infected. The backup immune system then kicks in in the absence of antibodies which is our B cells and T cells, which then produce new antibodies but it takes 1 or 2 days for the B and T cells to ramp up production of antibodies and why most people that are re infected don't end up in the hospital or die and just have light symptoms. The vast majority of ICU patients are from the unvaccinated. Studies have shown that the B cells and T cells bring back the original protection percentages after a year out, I'd have to look for the studies and I'll post them at a later time. Everyone should get vaccinated regardless and a booster for the most vulnerable just for starters. Of course the vaccines weren't designed for the Alpha Or Delta, so another reason why re infection is higher but again our B and T cells still kick in and protect us, and again why ending up in the ICU or death is very low. Of the 2977 vaccinated people in my Province of Ontario that tested positive, none ended up in ICU. There was no breakdown of the demographics of those 2977 people but we do know in Ontario that it's the 20-50 year old groups that are the getting re infected the most, so I suspect that is probably the case.
So yes his daughter probably still has protection but she should definitely get vaccinated or at least 1 vaccination because that has shown to be extremely more protective than either natural or vaccinated protection on their own. Not being vaccinated makes no sense at all. Cheers.