On 1/04/20 these countries were relatively unaffected by Covid-19. Different measures seem to be in place. Latvia (sort of lockdown), Estonia (some emergency measures), Lithuania (nationwide quarantine) and Belarus (almost no measures). We follow up these (reliable?) figures.
We can conclude that the number of deaths in these countries are very low compared to other countries. With 42 Estonia has the highest deaths/M POP of the four countries, but that is still low compared to the hardest hit countries like e.g. Belgium (726 deaths/M POP). If something changes we’ll be back to inform you about this.
sources: https://www.belarus.by/en/press-center/news/call-for-proposals-to-support-business-amid-coronavirus-outbreak_i_0000110850.html & http://lrv.lt/en/relevant-information/coronavirus-in-lithuania/relevant-information-1/important-information-to-foreign-nationals-in-lithuania & https://www.terviseamet.ee/en/covid19 & https://www.mk.gov.lv/en/aktualitates/regarding-declation-emergency-situation