This paper unpacks the effects of social networks on county-level COVID19 vaccinations in the US. We jointly assess the contemporaneous and dynamic network ef-fects of vaccination exposure, to distinguish between network-mediated contemporane-ous effects (e.g., "vaccine-hunter" Facebook groups crowd-source information about ac-cess and efficacy) and longer-term effects (e.g., vaccine exposure chips away vaccine hesi-tancy). Accounting for possible correlated shocks, socio-economic/spatial confounders, and pandemic-related shifters, we find positive stage-of-pandemic dependent contempo-raneous friendship network effects, and null dynamic network effect, thus sharply dis-tinguishing COVID19 vaccination from other infection-mitigating practices in terms of openness to social-learning over time.