{Reference Type}: Journal Article {Title}: "I can't see the forest for the ticks, uhm, trees …": The role of online forums in parents' vaccination trajectories. {Author}: Paul KT;Pichelstorfer A;Hansl N;Martin M;Pucker PM;Zhikharevich D; {Journal}: Soc Sci Med {Volume}: 357 {Issue}: 0 {Year}: 2024 Sep 5 {Factor}: 5.379 {DOI}: 10.1016/j.socscimed.2024.117183 {Abstract}: When it comes to health-related information-seeking behavior, online communities play a key role for some groups, such as parents. With a case study of online communities in a loosely organized vaccination system, that of Austria, we study how parents make use of a prominent online forum (parents.at) in their vaccination trajectories and situate this analysis in its socio-political context. Based on inductive qualitative analysis of relevant threads (n = 27), we find that parents use forums in three ways: First, the forum serves as a platform through which parents seek orientation in a loosely organized and fragmented vaccination system. Second, the forum offers space for sharing, collecting, and evaluating different forms of expertise. In doing so, parents carve out a space in which they can comfortably put lay expertise and credentialed expertise on a par, particularly in their advice to peers. Third, and on that basis, parents use the forum for deliberating on future or past vaccination-related decisions. In doing so, they frequently draw on idiosyncratic notions of individual risks and benefits. These three practices enable parents to accumulate and share what we label navigational capital. We conclude that parents resort to online spaces both out of a subjective need and, for some, as a result of a dysfunction of the national childhood vaccination program which offers little orientation for parents.