It's my understanding that if an effective prophylactic drug was available for covid, then the vaccines which are authorized for emergency use only, would no longer be allowed to continue.

There are several drugs that have proven to be a very effective prophylactic. Ivermectin is at the top of the list.

My thoughts mirror Georges. Its quite odd that they are not in widespread use. Some families have even had to go to court to get hospitals to administer these drugs.