The effects of long Covid could turn out to be a bigger public health problem than excess deaths, an academic has warned.

Those suffering with so-called long Covid have reported breathlessness, chronic fatigue and brain fog – months after initially falling ill with the virus.

A report from the Tony Blair Institute for Global Change is recommending that the Government highlight the issue in awareness campaigns.

The authors of the paper, titled Long Covid: Reviewing The Science And Assessing The Risk, say they believe awareness campaigns “would help drive compliance with containment measures such as the use of masks”.

In the report’s foreword, Tim Spector, professor of genetic epidemiology at King’s College London, said that, in the first few months of the pandemic, little attention was paid to the infected population who were not sick enough to go to hospital, who made up 99% of cases.

He said it turned out that Covid-19 is not just a bad flu, but in many people it behaves more like an autoimmune disease, affecting multiple systems in the body.

Prof Spector said the app launched in March by his group at King’s College London and the health-science company ZOE to capture the wider range of symptoms people were experiencing received data from more than four million people.

Researchers learned that “a great many people didn’t get better after two weeks as expected”, Prof Spector said, adding: “We kept following them and found out that a significant number still had problems after months.

“This is the other side of Covid: the long-haulers that could turn out to be a bigger public health problem than excess deaths from Covid-19, which mainly affect the susceptible elderly.”

The report said the King’s College study indicates that around 10% of those taking part in the survey had symptoms of long Covid for a month, with between 1.5% and 2% still experiencing such symptoms after three months.

The authors said these appear to be the most reliable statistics on which to base a rough estimate of the scale of long Covid in the population, adding that, while there is no clear evidence about prevalence in asymptomatic cases, it is likely to be lower than these percentages.

The report said long Covid seems rare in those under 18 and over 65, with higher prevalence among those of working age.

The median age of those affected is 45 and it affects women more than men.

“As Professor Spector says, long Covid is likely a bigger issue than excess deaths as a result of Covid, but, crucially, the risk must be considered alongside the economic impact and other health impacts linked to Covid restrictions,” the paper concluded.

Among their recommendations, the authors suggest further studies, awareness campaigns and mass testing to help with diagnosis.

Daniel Sleat, co-author of the report, said: “While long Covid poses a significant risk, it must be assessed alongside the wider impacts of Covid restrictions, both in economic and health terms, as governments determine their next steps on containment measures to avoid a full lockdown.”