Nonsense - once you are immune you have, as with other viruses, only a very small chance of catching again and usually with much less severity.
you have NO proof of that.
.. and there are indications there are already re-infections.
These are RNA viruses which mutate rapidly.
In fact, some think the SARS-CoV-2 had two forms,
with the less virulent form released in California
to protect the Democrats there in Nov. 2019.