Carrie Johnson had pneumonia. Do you risk contracting it?

The UK may not be in the grip of the widely predicted “quademic” of influenza, Covid, RSV and norovirus — not yet anyway — but flu is inflicting plenty of damage without the help of the other viruses. Nearly one in ten beds in my local hospital is occupied by people with flu and, like many others, it is struggling to cope with demand.

Flu can make you very ill, as Carrie Johnson discovered during her recent admission for pneumonia. While it can lead to lots of complications, ranging from ear infections and febrile convulsions to heart failure, paralysis (Guillain-Barré syndrome) and stillbirth, it is the impact on the respiratory system that causes the biggest problems.

A nasty cough may be par for those who catch flu, but according to recent Japanese research about 1 in 300 infections develop into pneumonia. And this proportion is much higher among older people, particularly those with underlying chest disease.

The odds of recovery vary with the individual and the cause of their pneumonia. Most cases in people with flu are due to secondary bacterial infection and, if sick enough to require hospital admission, then about one in ten will not survive (rising to one in three for those that need intensive care). The older you are, and the more underlying health issues you have, the greater the risk (see below).

Carrie Johnson recently contracted pneumonia

KIRSTY O’CONNOR/PA WIRE

One issue with flu is that it often makes people feel terrible, so spotting who is developing worrying symptoms of a more serious infection is much harder than in people with milder viral coughs and colds.

The cough itself is a poor indicator of severity. Innocent viral coughs and colds can easily last two to three weeks, sound “chesty” and produce yellow or green phlegm, while a child with pneumonia may just have a nagging dry cough.

New shortness of breath, particularly if severe enough to be noticeable at rest, should always raise concerns. Chest pain, often on taking a deep breath, is another red flag, as is coughing up blood or blood-tinged phlegm. And check your pulse. A resting heart rate consistently more than 100 in an adult is concerning.

Fever is traditionally another way to differentiate milder viral causes of cough from pneumonia because temperatures tend to be higher (38.5C or more) in the latter. However, unlike most other respiratory viral infections, flu often causes high temperatures too. And it can also make you feel awful, blunt your appetite and confine you to bed, all signs of more worrying infection, further muddying diagnostic waters.

Caught early, many cases of secondary chest infection and pneumonia can be treated with antibiotics at home, and the outcome is good, but it pays to have a high index of suspicion, particularly if you have underlying health issues such as existing chest disease that mean you are at higher risk of complications.

Prevention is key too. Antivirals such as Tamiflu, if taken within 48 hours of the onset of symptoms, may reduce complications such as pneumonia, and GPs can prescribe these to people at high risk during an epidemic. However, the best preventive measure is to take up the offer of vaccination if eligible.

Sadly, this isn’t foolproof either. In the five years between 2015 and 2020 flu vaccine efficacy ranged from 55 per cent to just 15, with children and younger adults generally having much better protection than older people. Indeed, in the 2016-17 season the vaccine is thought to have offered little or no protection to the over-65s.

Advances in vaccines since mean that the present versions do now work better in older people, and should reduce the risk of complications like pneumonia, even if you do catch the virus.

• Get vaccinated for winter

Unfortunately vaccine uptake this year hasn’t been as high as hoped, particularly among younger at-risk groups. And there is talk that this year’s mix of strains isn’t offering as much protection as last year’s, based on data from countries in the southern hemisphere (whose flu seasons start earlier than ours). Both of which could be factors behind the outbreak and pressures faced by the NHS.

I have had my flu jab. And if you are eligible and not had yours, I would urge you to try to get one. I say try, because supplies are limited (see below). Not only might the vaccine stop you catching flu, but it could help to ease pressure on the NHS.

It’s not just about being altruistic: the more people who are vaccinated, the less overrun your local hospital is likely to be, and the better the care you are likely to receive should you or any of your friends or family require it. At the very least please have your vaccine next year.

Flu jabs: what to know

• The odds of catching flu in a bad year can be as high as one in five.
• A limited supply of flu vaccines is still available — both on the NHS for those who are eligible and privately for others — but finding one can be difficult and access varies depending on where you live in the UK.
• The central booking service in England, for example, is now closed, but until the end of the month you can ring 119 to find out about local pharmacies that still offer the service (most are struggling to get stock). There is also a “find a pharmacy” service at nhs.co.uk
• I can’t speak for all GP surgeries but the combination of lower vaccine uptake and more people going to pharmacies means we still have some vaccines available — indeed, we recently provided top-up supplies to our local pharmacy. So it is worth asking your local practice.
• And if you want one, I would act sooner rather than later.
• For more information on antivirals and those most at risk from flu visit nice.org.uk