Originally posted by
Aragorn
Delta is twice as contagious ─ or transmittable, as you call it ─ as the original alpha strain, and just as deadly. Omicron is three times as contagious as delta, and thus six times as contagious as alpha, but far less deadly, resulting in fewer admissions to hospital and to the ICU wards.
Having had either variant does not stop one from getting infected again. However, that which has been stated ─ and why you are confused ─ is that if a person has recently had delta first and then omicron, then they appear to have developed a super-immunity, which even renders them immune against the common cold and certain other viruses.
Or at least, for a while, because immunity never lasts forever. My immunity after my first infection was evidently already all gone after six months, because that's when I got infected the second time.