How ‘twindemic’ of Covid-19 and flu could impact on hospitals this winter, according to an expert

We’ve all become armchair experts on terms like ‘pandemic’ and ‘endemic’ over the past two years, but ‘twindemic’ is a new one.

This week concerns have been raised about a possible ‘twindemic’ during the colder months, as a potential wave of Covid-19 infections looms, and flu infections surge again during the first winter with no restrictions since 2019.

But what is a ‘twindemic’ and why are flu cases set to soar this year? We spoke to an expert to find out.

Quite simply, a ‘twindemic’ means we’re likely to see the combined impact of Covid-19 and the flu this  winter, Martin Michaelis, professor of molecular medicine at the University of Kent, said.

Since the beginning of the pandemic, the Covid measures put in place not only helped to keep the virus at bay, but also “almost completely suppressed” the circulation of influenza viruses that cause the flu, he explained.

However, as restrictions to stop the spread of Covid - such as face masks and social distancing - are no longer in place, Professor Michaelis said it is “very likely” that both viruses will spread at the same time this autumn and winter.

What is a ‘twindemic’ and why are flu cases set to soar this year?

Covid infections have already started to rise again, and with both the flu and coronavirus being prone to spread via the air in poorly ventilated indoor spaces, both viruses are expected to surge this autumn and winter as the weather worsens and more time is spent indoors.

Hospitals are likely to therefore see both Covid and flu patients, which in turn “will further increase the pressure that hospitals already experience in a ‘normal’ winter”, Professor Michaelis added.

A warning from Down Under

Australia experienced a very severe flu season this year and since influenza viruses circulate between the southern and the northern hemisphere, tough flu winters in the southern hemisphere usually “forebode tough influenza winters in the northern hemisphere”, so we should “expect a resurgence of the flu in the UK,” said Professor Michaelis.

Although there will be people who will become infected with both viruses at the same time, the direct interaction between Covid and flu in the same body “remains to be further investigated”, although some data suggests that co-infection with both viruses at the same time “can result in more severe disease”, added Professor Michaelis.

He also noted that one of the reasons why some experts expect the flu to “come back with a vengeance” is that two years without the flu during Covid lockdowns may have reduced our immune protection against it, as our immune systems “have not been exposed to and trained by it”.

It’s therefore “very important” that everyone who is eligible to receive a flu jab gets one, Professor Michaelis added, as every flu jab “provides more protection than no jab”.

Those eligible should also get the Covid booster vaccinations as immune protection provided by the jabs and previous infections “wanes quickly” and boosters help to prevent serious Covid cases, the professor said.

“Covid and flu vaccines are our best chance to keep both diseases at bay this winter,” he said.

A ‘twindemic’ may be inevitable this winter, but at least we have the tools to deal with it.