Whole lotta Juelz Santana in this vid.
possible explanation:
A. illness upper respiratory tract (incl. nasal cavity) - fast build up, not "severe", no hospitalisation most cases, transmission, mutations, "cold like (delta) symptoms", detectable via RT-PCR test, can permeate blood-brain barrier.
B. illness lower respiratory tract - slower build up, can build up to be severe, mutations, can build up to hospitalisation, possible lung damage, possible follow on organ damage
-
high antibodies protect against the swift attack of A. secondary immune system protects against the build up of B in the absence of high antibodies and/or an effective defence.
waning antibodies opens up the possibility of URT infection, mutations, long covid, transmission etc as listed under A PLUS if the primary immune system is not good enough less likely but possible severe LRT infection.
waning longer-term secondary immune system ceteris-paribus means more severe cases.
them not being clear about the various stages (or "types" even) of infection is confusing people. in other words covid infection is not always the same in terms of what is actually infected (and the degree, of course).
this is why the common symptoms of vaccinated with delta are upper respiratory tract biased. i.e. in your head rather than your lungs e-grow

.
"
Headache, sneezing, sore throat, and loss of smell rounded out the rest of the top five symptoms for fully vaccinated people who contracted COVID.
Missing from that top-five list was coughing or shortness of breath, which were among the most frequently reported signs of COVID-19 early in the pandemic, before vaccines were available. A runny nose and sneezing were not commonly reported in initial cases."
there is no way to measure B/T-cell preparedness so we will see if this attenuates on the results side of things.