Spikevax is the second booster to be given the green light after Pfizer/Biontech's Comirnaty jab earlier this month.
The EU's drug watchdog on Monday approved booster doses of Moderna's Covid vaccine
for all over-18s, amid concerns that protection levels dip after initial jabs.
Spikevax is the second booster to be given the green light after Pfizer
's Comirnaty jab earlier this month.
"Data showed that a third dose of Spikevax given six to eight months after the second dose led to a rise in antibody levels in adults whose antibody levels were waning," the European Medicines Agency said.
Public health bodies within the 27-member bloc "may issue official recommendations on the use of booster doses, taking into account the local epidemiological situation", the Amsterdam-based EMA said.
It added that current data showed a pattern of side effects similar to that which followed a second dose of Spikevax.
"The risk of inflammatory heart conditions and other very rare side effects after a booster is being carefully monitored."
Earlier this month, the EU medicines watchdog approved booster shots of Comirnaty for over-18s as well as extra doses of Comirnaty and Spikevax for people with severely weakened immune systems.