[nostromo]

To actually answer the question: because immunity from one transfers to the other.

Omicron is basically a self-administering vaccine that is preventing Delta from spreading as easily.

[nathanyz]

I love this self-administering vaccine as it so elegantly explains the answer to the parent's question.

BUT, it is so elegant that you just provided fuel for the new conspiracy theory of how government forced us to get vaccinated by creating this crazy new variant in a lab that would essentially spread the vaccine without our permission. Just waiting for that to start bubbling up from the fringes ;)

[brahadeesh]

Unfortunately, things don't need to be one way or the other for conspiracy theorists to spin it the way they want to.