A second wave of Covid-19 could be more serious than the first as the National Health Service deals with a backlog of patients needing assessment and treatment and a potential outbreak of annual seasonal flu, researchers from from the country’s Academy of Medical Sciences said in the report.

The U.K. has already faced one of Europe’s worst outbreaks of SARS-CoV-2, with Prime Minister Boris Johnson falling seriously ill at one point. The country is one of many striving to ease restrictions on social contact while trying to revive failing economies and businesses.

Hospitals in the U.K. face an increased burden in winter when other respiratory diseases and common conditions such as heart disease tend to worsen. Covid-19 is also more likely to spread in cold weather as people spend more time indoors where the virus thrives, according to the report.

Flu Shots

Scientists and academics who wrote the report called for expansion of programs to test, track and trace those who have been exposed and are infected. Control measures and adequate stocks of personal protective equipment also need to be assured for hospitals and nursing homes, they said.

Flu vaccinations will also be important to prevent hospitals from becoming overwhelmed, the report said. Seasonal flu is regularly responsible in part for the NHS’s “winter crisis” when some hospitals fill up with sick patients.

The average number of people that one infected person transmits the coronavirus to, often called the reproduction rate or R-naught, could rise to 1.7 beginning in September, according to the report. That would lead to a peak of hospital admissions and deaths in January and February which could be worse than the first wave.

The current reproduction rate in the U.K. is about 0.7-0.9, which means the epidemic is diminishing overall. Ministers have previously warned the U.K. could go back into lockdown if the R rate rises above one.

The report is not a prediction but a “reasonable worst-case scenario,” and calls for intense preparation, the authors said.