An antibody cocktail that gives immediate protection against coronavirus and could bring outbreaks on cruise ships and in care homes to a halt is being trialled in Britain.
The treatment has been developed by pharmaceutical giant AstraZeneca from Covid-fighting antibodies found in the blood of a patient who survived the virus.
With a vaccine, the body takes around six weeks to develop immunity after an injection. With the cocktail, it is thought that the antibodies are able to fight off the virus immediately and may last for a year before needing to be replenished.
The Government hopes the treatment could protect hundreds of thousands of people who cannot be vaccinated because their immune systems are compromised.
It could also be used to prevent vulnerable patients from catching Covid in hospitals and care homes, or be issued quickly to cruise ship passengers and crew should a traveller be diagnosed with the virus.
The first trial participant is due to be given the drug at North Manchester General Hospital on Saturday, and results are expected in the spring.
Describing how the drug could be used, Sir Mene Pangalos, an executive vice president at AstraZeneca, said: "So imagine a cruise ship that has an outbreak where half the people have been vaccinated and half haven't because of access to the vaccine. You'd be able to go and immunise the whole cruise ship with this antibody and everyone will be protected straight away.
"Or where there has been a case confirmed in a care home, you will go and immunise everybody in the care home to protect them from progressing on with the disease, or in a hospital or a school. Or someone comes to the doctor or hospital with confirmed Covid disease and symptoms, and we treat them with the antibody and then they go home and we hopefully stop them getting sicker.
"There's also going to be a significant number of people, even in a world where vaccines are highly effective, who will not respond to vaccines, or will not take vaccines, and so having potential therapeutics I think it is important."
Kate Bingham, who chairs the Government's Vaccine Taskforce, said the antibody cocktail could also be used to give front line workers immediate protection, adding: "It will work instantly, so there may be examples of the military or healthcare workers or people that need immediate protection, and you could use this antibody cocktail, as opposed to waiting. This is part of the portfolio to protect the whole UK."
The team at AstraZeneca screened thousands of antibodies to find the most effective at fighting coronavirus, and eventually used two types from a Covid survivor who had an extremely potent immune response.
However, the antibody cocktail will not be rolled out to a large proportion of the population because it is far more expensive and difficult to make than vaccines. While a vaccine costs just a few pounds, a dose of antibodies can cost hundreds of pounds.
But there are around 350,000 people in Britain who are unable to be vaccinated so, if successful, they are likely to be offered the treatment.
Phase Three trials on 1,000 volunteers are taking place at nine sites across Britain, but the team is planning to recruit a further 4,000 participants globally, and researchers are urgently calling on more people to volunteer.
Sir Mene also said the Oxford vaccine team was still "on track" to have final results before Christmas, adding: "We're still hoping we might be able to dose, if we show the vaccine is safe and effective, towards the end of the year.
"We're not going to be able to vaccinate the whole population of the UK immediately. There is a large group of people who will have to wait a while to receive the vaccination."