Recent surges in antivaccine activism and other antiscience trends now converge with rising antisemitism. During the COVID-19 pandemic, authoritarian elements from the far right in North America and Europe often invoked Nazi imagery to describe vaccinations or at times even blame the Jewish people for COVID-19 origins and vaccine profiteering. Such tropes represent throwbacks to the 14th century, when European Jews were persecuted during the time of the bubonic plague. This article provides both historical and recent perspectives on the links between antiscience and antisemitism, together with the author's personal experience as a Jewish vaccine scientist targeted by both dark forces. New approaches to uncoupling antisemitism from antiscience, while combating both, are essential for saving lives and preserving democratic values.