Although most protective behaviors related to the COVID-19 pandemic come with personal costs, they will produce the largest benefit if everybody cooperates. This study explores two interacting factors that drive cooperation in this tension between private and collective interests. A preregistered experiment ( N = 299) examined (a) how the quality of the relation among interacting partners (social proximity), and (b) how focusing on the risk of self-infection versus onward transmission affected intentions to engage in protective behaviors. The results suggested that risk focus was an important moderator of the relation between social proximity and protection intentions. Specifically, participants were more willing to accept the risk of self-infection from close others than from strangers, resulting in less caution toward a friend than toward a distant other. However, when onward transmission was the primary concern, participants were more reluctant to effect transmission to close others, resulting in more caution toward friends than strangers. These findings inform the debate about effective nonclinical measures against the pandemic. Practical implications for risk communication are discussed.