The Center for Propaganda and Disinformation Analysis on 10.05-29.08.2021 monitored the Polish and Russian information space in the context of information on vaccines against COVID-19. The study was conducted using the Pulsar online information monitoring and analysis platform. For the sake of this analysis, 5 online mainstream media from Poland and Russia were selected. Polish media selection was based on the 2020 ranking of the most opinion-forming Internet portals, along with 5 additional information portals, bypassing the industry ones: onet.pl, wp.pl, interia.pl, wpolityce.pl and gazeta.pl. Russian media was selected on the basis of the 2020 ranking of the most opinion-forming Internet portals with nationwide coverage, available in the Pulsar media database: Rbc.ru, Gazeta.ru, Lenta.ru, Kp.ru and Fontanka.ru.