New Oxford research led by Professor Gupta and Dr Lourenco from the Department of Zoology stresses the urgent need for antibody blood (serological) tests. These could determine what proportion of the population has already been infected, and therefore has immunity, The Blue reports.

The need for serological testing is critical to giving insight into how many people have had the disease and now have immunity — if a high proportion have already had it, this big step towards herd immunity would be a game changer in coming weeks and months.

The research shows how an ambiguity surrounding the proportion of the population at a high risk of developing severe symptoms could result in inaccurate estimates of the stage of the epidemic in the UK.

This ambiguity stems from inadequate current data. It is difficult to tell whether the number of reported deaths is due to a small high-risk group within a population with a high number of infection cases; or, by a larger risk group within a population with fewer infection cases.

They generated a computational data model that looks at the rates of transmission between three main groups of people: never infected, currently contagious, and recovered non-contagious.

Being able to identify the size of the group of people in the population who are more susceptible to severe disease is essential in making it possible to predict how many more are at risk of dying as a result of Covid-19.

It also allows public health policy to be adapted in a way which is more beneficial for everyone, depending on how many people are likely to suffer badly from the illness.