The European Medicines Agency (EMA) approved Moderna corona vaccine to be used as a booster dose for everybody who's at least 18 years of age.
The recommendation is based on researches that the third dose of Spikevax increased the number of antibodies for SARS-CoV-2 that causes COVID-19. The number of antibodies is decreased remarkably 6-8 months after the second dose. A booster dose is half of the dose used in the primary vaccination.
By the current data, the side effects from the booster jab are similar to the ones that were reported after the second dose.
The implementation of vaccination campaigns remains to each EU member state. The EMA said the risk of inflammatory heart conditions or other very rare side effects after using Moderna is being monitored.
Estonian Medicines Agency