The COVID-19 pandemic may impact the development of infants' social communication patterns with their caregivers. The current study examined continuity, stability, and bidirectional associations in maternal and infant dyadic Emotional Availability (EA) before and during the COVID-19 pandemic. Participants were 110 Israeli mother-infant dyads (51% girls) that were assessed prior to (Mage = 3.5 months) and during (Mage = 12.4 months) the pandemic. At both time points, mother-infant interactions were observed during play (nonstressful context) and tasks designed to elicit infant frustration (stressful context). Maternal and child EA were coded offline. Maternal EA demonstrated no significant mean-level changes from before to during the COVID-19 pandemic, whereas infant responsiveness and involvement increased over time. Stability and bidirectional associations in EA differed by context and were evident only in the stressful context. Mothers' perceived levels of social support further moderated these associations. Specifically, infants' pre-pandemic responsiveness and involvement predicted maternal EA during the pandemic only when mothers reported low levels of social support. Our findings suggest that maternal and child EA were not adversely impacted by the COVID-19 pandemic. However, patterns of EA demonstrated moderate-to-no stability over time, suggesting considerable individual differences in trajectories of EA.