THOSE who have been infected with coronavirus can't catch it again, scientists say. 

Experts had feared patients could catch the bug twice – after as many as ten per cent of recovered coronavirus patients in China tested positive again after being discharged from hospital.

⚠️ Read our coronavirus live blog for the latest news & updates

However, South Korean scientists have now concluded that Covid-19 patients cannot relapse after recovering from the disease – and blame faulty tests for second positives.

This will greatly reassure Governments threatened by the prospect of a never-ending cycle of infection and reinfection.

According to South Korea’s central clinical committee for emerging disease control, positive test results on people who had tested negative were the result of “fragments” of the virus lingering in their bodies, but with no power to make them or ill or to infect others.

A total of 277 patients appeared to have become reinfected with the illness – raising fears that mutations in the virus could prevent patients from developing immunity to it, which would complicate the task of finding a vaccine and eliminate the possibility of “herd immunity”.

Oh Myoung-don, the head of the committee, said that the later positive results were caused by shortcomings in the polymerase chain reaction (PCR) test that detects the virus’s genetic information, or RNA, in samples taken from patients.

Harmless traces

The test is unable to differentiate between “live” RNA and harmless traces that can remain in the body of someone who has fully recovered.

The committee said in a statement: "RNA fragments still can exist in a cell even if the virus is inactivated.

"It is more likely that those who tested positive again picked up virus RNA that has already been inactivated."

The conclusion is consistent with findings by the Korea Centres for Disease Control (KCDC) that seemingly “relapsed” patients were not infectious.

Dr Oh said: "The respiratory epithelial cell has a half-life of up to three months, and RNA virus in the cell can be detected with PCR testing one to two months after the elimination of the cell."

Give now to The Sun's NHS appeal

BRITAIN’s four million NHS staff are on the frontline in the battle against coronavirus.

But while they are helping save lives, who is there to help them?

The Sun has launched an appeal to raise £1MILLION for NHS workers. The Who Cares Wins Appeal aims to get vital support to staff in their hour of need.

We have teamed up with NHS Charities Together in their urgent Covid-19 Appeal to ensure the money gets to exactly who needs it.

The Sun is donating £50,000 and we would like YOU to help us raise a million pounds, to help THEM. No matter how little you can spare, please donate today here: www.thesun.co.uk/whocareswinsappeal.

He also claimed that coronavirus cannot cause chronic illness by lingering inside the nucleus of human cells.

In this respect the virus that causes Covid-19 is different from the HIV and hepatitis B viruses, which can remain dormant and reactivated later.

South Korea reported no new cases of local infection yesterday, for the first time since February.

There were five new cases, all of them in patients who contracted the virus outside the country, taking the national total to 10,765 cases including 247 deaths.

South Korea's "trace, test, treat" policy is being lauded as one of the world's best approaches to tackling the virus.

Short-term immunity

Sir Patrick Vallance, the Government’s chief scientific adviser, and Prof Chris Whitty, Boris Johnson’s chief medical adviser, have previously sought to reassure the public about catching coronavirus twice.

They claimed those who have had the virus once will develop some immunity – and it is rare to get an infectious disease again.

Sir Vallance revealed some people do catch infectious diseases a second time, but that it is rare and he added that there was no evidence to suggest that it would occur with the coronavirus.

Meanwhile, Prof Whitty explained that with diseases, even if there is no long-term immunity, there is normally some short-term immunity.

TV's Dr Hilary Jones, said there currently isn't enough evidence to say if you caught Covid-19 and recovered whether you'd be immune for life, or whether you could you catch it again.

He told The Sun: "Currently we don’t know enough about this virus to say for sure that you can’t get it twice but it is unlikely.

"If it turns out to be like seasonal flu it’s possible there might be another round of virus next winter, as we don’t know yet how strong people’s immunity will be.

"We will know more in the future and soon a test will become available to show whether someone has had the virus and has developed immunity."

Meanwhile, British scientists are currently working round the clock on a coronavirus vaccine – and have said they will know by early summer if it works.

It’s possible there might be another round of virus next winter

Human trials of the Oxford University jab began last week.

The team has struck a deal with pharmaceutical giant AstraZeneca for a huge roll-out of the vaccine at cost price.

The company has pledged to produce 100million doses this year if the trials prove positive.

And it has promised to put the UK at the front of the queue for early access to millions of jabs.

Sir John Bell, Regius Professor of Medicine at Oxford University, said several hundred volunteers had already been given the experimental injection.

He said the team should get a “signal about whether it's working by the middle of June”.

A successful vaccine is crucial to ending restrictions and life returning to normal.

Lead researcher on the Oxford project Professor Sarah Gilbert has previously said she is 80 per cent confident it will succeed.

CORONAVIRUS CRISIS – STAY IN THE KNOW

Don't miss the latest news and figures – and essential advice for you and your family.

To receive The Sun's Coronavirus newsletter in your inbox every tea time, sign up here.
To follow us on Facebook, simply 'Like' our Coronavirus page.

Get Britain's best-selling newspaper delivered to your smartphone or tablet each day – find out more.

Source: Read Full Article