A Covid antibody cocktail drug has been approved for UK patients — but it may be weaker against super-strain Omicron.
Britain's medical regulator gave sotrovimab, sold under the brand name Xevudy, the green light after clinical trials found it could treat patients who were already sick.
It showed that among patients with mild to moderate Covid, it slashed hospitalisations by 79 per cent.
Regulators say it should be used in patients at risk of developing serious illness within five days of their symptoms appearing.
The UK has secured 100,000 doses.
Its developers say the drug works against some mutations on Omicron, but experts fear it will be less effective against the strain. This is yet to be tested in clinical trials.
Sotrovimab is the second monoclonal antibody treatment approved in the UK, which works by mounting an immune response in patients too weak to make their own.
In August the Ronapreve drug was cleared for use in UK patients by medical regulators, and is now being administered to patients in NHS hospitals.
GlaxoSmithKline's monoclonal antibody drug cuts the risk of Covid patients dying or being admitted to hospital by 79 per cent, trial results have found (stock)
Monoclonal antibodies are lab-produced molecules that mimic human antibodies — disease-fighting proteins made by the immune system
The Medicines and Healthcare products Regulator Agency (MHRA) said Sotrovimab was found to be 'safe and effective' at reducing the risk of hospital admission.
The monoclonal antibody works by mounting an immune response against the virus in people whose bodies are too weak to do it on their own.
It binds to the Covid spike protein — which it uses to invade cells — stopping the virus from sparking a serious infection.
Sotrovimab has been authorised for use in people who have mild to moderate Covid infection and at least one risk factor for developing severe illness, such risk as being over 60, obesity, diabetes mellitus or heart disease.
It is approved for individuals aged 12 and above who weigh more than 40kg.
Dr June Raine, MHRA chief executive, said: 'I am pleased to say that we now have another safe and effective Covid-19 treatment, Xevudy (sotrovimab), for those at risk of developing severe illness.
'This is yet another therapeutic that has been shown to be effective at protecting those most vulnerable to Covid-19 and signals another significant step forward in our fight against this devastating disease.
'With no compromises on quality, safety and effectiveness, the public can trust that the MHRA have conducted a robust and thorough assessment of all the available data.'