Scientists have confirmed just how long it takes for symptoms of the coronavirus to develop in infected people.

The team of US-based immunologists studied more than a hundred cases of Covid-19 in order to give a better estimate of its incubation period in humans.

Their report, published in the Annals of Internal Medicine, found that, on average, it takes around five days for symptoms of Covid-19 to develop.

They also found that 97 per cent of all people who get the virus will develop symptoms within 11 days after they were first infected.

The report said that the current government advice, which tells people suspected of having the disease to self-isolate for 14 days, is “well supported by the evidence”, and that “the estimates presented here can help public health officials to set rational and evidence-based COVID-19 control policies.”

What are the symptoms of Covid-19?

The Covid-19 strain of coronavirus, which has already infected more than 119,000 people around the world, has three main symptoms:

  • A dry cough
  • Fever
  • Breathing difficulties (in more severe cases)

Who is worst affected by coronavirus?

As with other viruses, like the flu, some groups will be worse affected than others. Older people, and those with pre-existing conditions, are at greater risk of dying from Covid-19.

This is because those groups are likely to have weaker respiratory systems - one of the main areas of the body that the virus attacks.

In contrast, healthy toddlers and children seem to be only very mildly affected by the virus, according to the World Health Organisation.

Figures from China, where the vast majority of Covid-19 cases have been reported, also suggest a difference in the rate of death in men and women.

According to cases in the country, 2.8 per cent of men who contract the virus die from it, in contrast to only 1.7 per cent of women.

But health officials have cast doubt on the relevance of this result for the wider world, pointing out that smoking is much more prevalent among men than women in China, and causes respiratory conditions that significantly increase the risk of complications with Covid-19.

How can I protect myself from coronavirus?

The most effective ways to prevent the spread of coronavirus is to:

  • Avoid close contact with sick people
  • Try not to touch your face with unwashed hands
  • Use tissues to catch sneezes and coughs, and put them in the bin and wash your hands straight away
  • You should wash your hands regularly with soap and water for at least 20 seconds

Coronavirus: What you need to know

  • What is coronavirus?: COVID-19 is a respiratory illness that can affect lungs and airways. It is caused by a virus called coronavirus.
  • What caused coronavirus?: The outbreak started in Wuhan in China in December 2019 and it is thought that the virus, like others of its kind, has come from animals.
  • How is it spread?: As this is such a new illness, experts still aren’t sure how it is spread. But.similar viruses are spread in cough droplets. Therefore covering your nose and mouth when sneezing and coughing, and disposing of used tissues straight away is advised. Viruses like coronavirus cannot live outside the body for very long.
  • What are the symptoms?: The NHS states that the symptoms are: a dry cough, high temperature and shortness of breath - but these symptoms do not necessarily mean you have the illness. Look out for flu-like symptoms, such as aches and pains, nasal congestion, runny nose and a sore throat. It’s important to remember that some people may become infected but won’t develop any symptoms or feel unwell.
  • What precautions can be taken?: Washing your hands with soap and water thoroughly. The NHS also advises to cover your mouth and nose with a tissue or your sleeve (not your hands) when you cough or sneeze; put used tissues in the bin immediately and try to avoid close contact with people who are unwell. Also avoiding touching eyes, nose and mouth unless your hands are clean.
  • Should I avoid public places?: Most people who feel well can continue to go to work, school and public places and should only stay at home and self isolate if advised by a medical professional or the coronavirus service.
  • What should I do if I feel unwell?: Don’t go to your GP but instead call NHS 111 or look online at the coronavirus service that can tell you if you need medical help and what to do next.
  • When to call NHS 111: NHS 111 should be used if you feel unwell with coronavirus symptoms, have been in a country with a high risk of coronavirus in the last 14 days or if you have been in close contact with someone with the virus.