ABSTRACT Knowledge about HIV transmission and prevention is a necessary step for adopting preventive behaviors. We assessed HIV knowledge and its correlation with the perceived accuracy of the “Undetectable = Untransmittable” (U=U) slogan in an online sample with 401 adult Brazilians. Overall, 28% of participants showed high HIV knowledge level. The perceived accuracy of the U=U slogan significantly correlated with HIV knowledge. Younger participants, those reporting lower income or lower education, or who had never tested for HIV showed poorer […]