Anti-vaccine advocates have long engaged in a harmful and baseless campaign that ties infertility to vaccines. Preliminary analysis of a large, real-time data collection of Twitter posts that filtered for COVID-19 vaccine and fertility content revealed a surprising moment when, after the vaccines rolled out, anti-vaccine advocates made a new tie to menstrual health not previously seen in anti-vaccine advocacy. We traced the tie to a co-opting of reports commencing soon after vaccines were distributed when people began to report menstrual anomalies—anomalies that would be alarming unless they could be confirmed to be a temporary side effect. These reports, which were attempts to cross-check experiences with others, soon became new sites of “convergence” where information exchange became disordered. Discourse analysis describes how a politicized debate around vaccines, reproductive health, the medical establishment, and the validity of lived experiences was differently argued. This disordered information space can be further characterized by three waves of “social convergence” of people with varying intentions and knowledge. Furthermore, a verification analysis of international popular press articles revealed a long delay before medical groups addressed the link anywhere in the world. Meanwhile, worrisome links between vaccines and other health matters—myo- and pericarditis—were rapidly confirmed with their attendant fears managed. One year after vaccines were distributed, insufficient messaging to women and menstruators persisted; meanwhile, disinforming behaviors were fueled by worry and the ready presence of anti-vaccine activists, illustrating how marginalized topics provide “fertile ground” for information disorder. Results contribute theoretically to our understanding of information disorder, with additional lessons for public health communication and disinformation mitigation.

Vaccine hesitancy has always been a public health concern, and anti-vaccine campaigns that proliferate disinformation have gained traction across the US in the last 25 years. The demographics of resistance are varied, with health, religious, and, increasingly, political concerns cited as reasons. With the COVID-19 pandemic igniting the fastest development of vaccines to date, mis- and disinformation about them have become inflammatory, with campaigning allegedly including racial targeting. Through a primarily qualitative investigation, this study inductively examines a large online vaccine discussion space that invokes references to the unethical Tuskegee Syphilis Study to understand how tactics of racial targeting of Black Americans might appear publicly. We find that such targeting is entangled with a genuine discussion about medical racism and vaccine hesitancy. Across 12 distinct voices that address race, medical racism, and vaccines, we discuss how mis- and disinformation sit alongside accurate information in a “polyvocal” space.