Jonas Salk told us that as kids.
Did his polio vaccine build a virus proof filter in you nose?
Function of vaccine is hugely mis-understood.
ONLY function of vaccine is to create anti-bodies in your body. Those come into play AFTER infection occurs. Those extra stock of anti-bodies help you fight the virus and reduces chance of serious illness. Many vaccines are so effective, even when infection takes place, the virus is killed off quickly, no symptoms appear, and it gives the (false) impression that the vaccine prevented infection.
What is the last time we tested people for polio or smallpox or influenza? Never! But covid tests are being done incessantly. But testing positive for covid means little if there are no symptoms or very mild symptoms.