An alarming recent survey of over 700 gay and bi men in New York City revealed that only:
39% believe that maintaining an undetectable viral load offers “a lot of” or “complete” protection from HIV transmission. Including...
28% of HIV-negative men and...
49% of male PrEP users and...
58% of HIV-positive men who agree...
However 70% of those surveyed do understand daily PrEP provides that level of protection.
The Centers for Disease Control and Prevention confirms that being undetectable prevents HIV transmission (i.e. that undetectable equals untransmittable is true). You can believe it.