Since non-sterilizing, intramuscular vaccines provide blood/serum antibodies that offer protection against serious illness/death, rather than nasal/mucosal immunity which prevents infection via the upper respiratory system, recipients of existing Covid vaccines can be infected. If the vaccine works, they will be protected from serious illness. If there is vaccine escape (e.g. Delta) the risk of serious illness or death is that same as an unvaccinated person, i.e. a few percentage points.

After recovery from their Covid infection, they will have long-lasting immunity from infection, transmission and serious illness, with no further need of intramuscular vaccines or boosters. To shorten the duration of infection, accelerate recovery and reduce the risk of long-term side effects, a variety of early treatments are available, including monoclonal antibodies. Early treatment is especially important for those with other medical complications.

In the EU, recovery from Covid (proved via antibody test) enables qualification for the EU health pass, including travel to/in EU. At present, that duration is limited (as are vaccines), but that will hopefully change as more data becomes available from ongoing studies of both natural and artificial immunity.