The United Kingdom says it will offer booster jabs to people aged over 50, with other countries expected to follow suit.
There are fears the upcoming winter season could see coronavirus infections rise.
Saying it wants to prepare for the worst, the British government has announced a rollout of third doses of vaccine against COVID-19 from next week.
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Some 30 million people will be eligible, including everyone aged over 50, people with underlying conditions and health workers.
They will be given at least six months after the administration of the second dose.
But is that enough?
Presenter: Kim Vinell
Chris Smith – Consultant virologist and editor of The Naked Scientists
Patrick Tang – Division chief of microbiology at Sidra Medicine
Azeddine Ibrahimi – Head of Biotechnology Lab at the Rabat Medical School