A possible alternative to a vaccine, for people without functioning immune systems, is entering its final stage of trials.
The injection was developed using antibodies – made by the immune system to fight infection – produced by a single Covid patient in the US.
It is hoped it could provide at least six months’ protection for patients who cannot receive vaccines.
Trials involving 1,000 UK participants begin in Manchester on Saturday.
A further 4,000 people are involved in the trial globally, which is being organised by pharmaceutical giant AstraZeneca.
Participants will be given either an injection containing two different Covid-19 antibodies, which have been