Half the population could already have the coronavirus, according to a new study.

Researchers from the University of Kent in Medway are now helping gather evidence to test the theory, developed by colleagues at Oxford.

If confirmed it would suggest fewer than one in every 1,000 of those infected with Covid-19 requires hospital treatment - and the vast majority have mild symptoms.

Therefore, the UK may have already acquired "herd immunity" to the disease - and "social distancing" restrictions imposed by the government on Monday may be lifted sooner than expected. But until concrete evidence emerges, the restrictions MUST still be respected, researchers insist.

The study was led by Sunetra Gupta, professor of theoretical epidemiology at Oxford University.

“We need immediately to begin large-scale serological surveys - antibody testing - to assess what stage of the epidemic we are in now,” she told the Financial Times.

The UK government has bought 3.5m antibody tests for the coronavirus, the Health Secretary Matt Hancock said yesterday. These tests establish whether someone has recovered from the virus.

Prof Gupta says she is confident humanity will build up herd immunity against Covid-19. This is the theory the virus will stop spreading when enough people are infected.

In order to test whether people do become immune, Prof Gupta's team is working with colleagues with colleagues at the University of Kent and at Cambridge.

They want to start antibody testing on people later this week and hope to obtain preliminary results within days.

The Oxford group's modelling suggests Covid-19 reached the UK by mid-January at the latest.

It then spread without detection for a month before the first cases of coronavirus in England were officially recorded at the end of February, according to the theory.

The group reached their conclusions about the behaviour of the virus after studying reports of Covid-19 cases and deaths from the UK and Italy.

Prof Gupta did not criticise the government for imposing the lockdown this week. Because even if the Oxford theory is right, the social distancing measures will help slow the spread of disease and reduce the number of people needing hospital treatment.

Imperial College project

The University of Kent is also set to begin working with Imperial College London on a research project to develop antibodies that target coronavirus - with the aim of developing a new therapy for Covid-19.

Antibodies are produced by the body’s immune system that recognise viruses, block the virus entry and instruct the immune system to destroy it.

A panel of antibodies that might bind to proteins from the Covid-19 coronavirus have already been identified from people infected with the 2003 SARS strain.

The research project will look to develop a potential antibody therapy, eventually to be used in clinical trials - which will determine if the developed therapies can treat Covid-19.

For this project, Kent will be working alongside Hong Kong University and the National Institute for Biological Standards and Control, as well as Imperial College.

Positive results from this research could include vital breakthroughs in actions against the virus, putting the NHS in a stronger position and providing hope for the pandemic’s eventual close.

Professor Philippe De Wilde, deputy vice-chancellor of research & innovation at Kent, said: "The University of Kent has very strong research groups in Pharmacy (Medway School of Pharmacy, joint with University of Greenwich) and Biosciences.

"These groups are focusing their efforts on helping the NHS and government agencies during the current crisis.

"The University of Kent has supported this research for years, and I am glad that we have the knowledge and the researchers available to contribute to the national effort."

Both University of Kent projects are being led by Dr Nigel Temperton, senior lecturer in biological sciences, at the Medway School of Pharmacy.

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