Vaccinated people from anywhere are welcome.
People who have undergone a COVID-19 vaccination programme (ie they've gotten both shots of either Pfizer, Moderna or AstraZeneca vaccine and two weeks have passed since the second dose; or they've gotten the single-shot Johnson & Johnson vaccine and two weeks have passed since) within the past year do not need to self-isolate or test for the coronavirus. Just EU Covid certificate is required.
Estonias safe label: https://www.visitestonia.com/en/media/press-releases/estonia-launches-you-are-safe-here-quality-label-to-reassure-visitors
More detailed information: https://www.visitestonia.com/en/why-estonia/coronavirus-and-travelling-to-estonia