The ‘long Covid’ time bomb: an interview with Tim Spector

It sometimes seems as if Professor Tim Spector, of King’s College London, was conjured up especially to be a walking, talking rebuke to Public Health England.

Where PHE has been lumbering, slow to respond to the fast-moving virus, Spector has been nimble, quick to see opportunity and adapt. This time last year, as Boris was preoccupied with the defining question of his premiership — who could possibly have leaked a disobliging story about his girlfriend’s dog — Tim Spector was concocting a plan for how to collect data about Covid from around the country. His Covid Symptom Study app (CSS), a year old this week, has been a triumph. There are now 4.5 million users, logging their symptoms daily.

‘I had the idea for the app about 18 March last year when the university told us all to go home and stop our clinical studies,’ he says. ‘I’d been working with twins for the past 28 years. There were 14,000 twins we were studying so my first thought was: how can we keep in contact with them during this?’ Spector sounds busy and energetic on the phone, and he looks busy and energetic when I stalk through his photos online: slim and wiry, almost permanently tanned and twice pictured in full cycling Lycra.

Spector is a professor of genetic epidemiology, but he’s also an expert on gut bacteria, and co-founder of a company called Zoe which aims, it says, ‘to analyse your unique gut, blood fat and blood sugar responses’. It was the Zoe app that paved the way for CSS. ‘The Zoe app was pretty much repurposed overnight,’ he says. ‘There was nothing else really like it at the time. Amazingly, we managed to launch within a week from starting, and all that without any official backing or help.’ Spector is 62, but, as he shared on Twitter recently, he has the gut microbiome of a man of 40. And oddly, this might well be relevant to the fightback against Covid.

Anyway, Spector’s full of vim and just the man to lead a war effort, which is, in a way, what he’s done. ‘People had just been told go home, shut the door and don’t annoy the hospitals or your GP,’ he says. ‘But a lot of people really wanted to help, and they saw the app as a way of doing that.’ And the app users really did help. At a time when the NHS was only accepting two symptoms — a fever and a cough — data from Spector’s CSS app showed that anosmia (loss of smell) was a significant symptom — not that PHE was listening. Spector told the BMJ: ‘I had dealt with six different government bodies; nobody knew who was in charge… I was sceptical that they [PHE] had public health interests at heart: they didn’t seem to want to engage with the public, speak to doctors.’ As it happens, Duncan Selbie, head of PHE, was even in May telling No. 10 that he was more interested in obesity than the coronavirus, and though there was talk about removing Selbie, the Cabinet Office felt it would be ‘too disruptive’. You’d have thought Covid was pretty ‘disruptive’ too. Never mind.

In early June, Spector warned that Covid patients were experiencing strange rashes. Had PHE learnt from the anosmia debacle? Nope. Spector told a newspaper at the time: ‘GPs are unaware of it, so they are sending people away, or NHS 111 is not recognising it as a possible symptom.’

Spotting anosmia was the app’s first great insight, but the second, says Spector, was that a great many people didn’t get better after two weeks as expected. As CSS app users kept logging symptoms, the next challenge became clear: long Covid, the mysterious set of symptoms that persist beyond the acute illness. ‘The long-haulers could turn out to be a bigger public health problem than excess deaths from Covid-19, which mainly affect the susceptible elderly,’ wrote Spector recently. ‘This is the other side of Covid.’

I ask him now, how big a problem is it? Isn’t it just a very small percentage who don’t recover? ‘I think most estimates are now that with post-Covid-19 viral syndrome, as it’s now called, 10 per cent of people are still going to have some symptoms after three months, even if they are very mild, so that’s 400,000 people minimum,’ says Spector. ‘What we’re seeing is that half of those tend to get better every three months so those numbers do go down, but even if that’s a quarter of the year, that’s 100,000 in a year’s time still with symptoms, and that’s a lot of people for a chronic condition. That’s more than many autoimmune diseases. Other viruses can do it but not on this scale.’

This is unsettling. Spector is using the official figures for confirmed cases — 4.2 million in the UK. But the true number of infections is without doubt much, much higher. Modelling from Edge Health suggested in January that one in five people in England have been infected. That’s some 12.4 million just in this country. One and a half million long Covid sufferers is an NHS nightmare. And unsurprisingly there’s already a great angry divide on the subject. There are the long Covid forums full of desperate, exhausted men and women — long-haulers they call themselves — suffering from breathlessness, hair loss, gut pain and crippling headaches. And then there’s the snap-out-of-it crowd, for whom long Covid is just another excuse for malingering. It’s ME all over again, they say.

Is long Covid simply ME? I ask Spector. Is it identical to other post-viral syndromes or is there a set of symptoms specific to it? ‘There are some similarities with the general post-viral thing but there are also some very specific things that set it apart: Covid toes; autoimmune skin rashes… you generally don’t get diarrhoea, you don’t get intermittent fevers,’ he says. ‘Yes, headache, fatigue and shortness of breath and muscle pain might be common to a number of them, but there are significant differences.’ Other disease experts agree. ‘It appears that post-Covid symptoms tend to be more common, severe and longer-lasting than other viral illnesses, such as influenza,’ says Timothy Hendrich, a viral immunologist at the University of California.

Anecdotes make bad evidence, I know, but I have a great friend in his mid-forties who had Covid relatively mildly, about the same time as I did. As I recovered, he went under. At times he has said it’s like breathing hot sand. He has had the distinctive Covid toe rash, pins and needles and still, a year later, has headaches, but the most distinctive symptom — true of most post-viral illness — is exercise intolerance. If he goes for a brisk walk, he’s prone for weeks after. You simply can’t snap out of it.

As with Covid last year, so with long Covid this year — for the most part, so far, we’re in the dark. But thanks to initiatives like Zoe’s CSS app, patterns are beginning to emerge: ‘The greater the number of different symptoms you have in the first week is the best predictor of whether you are still going to have symptoms over a month or two months,’ says Spector. Being a woman is also a risk: ‘Because age is such a strong factor, we don’t see a difference between a 60-year-old man and a 60-year-old woman, but we do see a big difference in 30-year-olds,’ says Spector. There’s evidence that women are twice as likely to feel fatigued up to 11 months after leaving hospital, and six times more likely to experience breathlessness. ‘I suspect it is to do with the immune response to the virus,’ says Spector. ‘Women have a more robust immune defence system than men, so if long Covid is an over-reaction, that might explain it.’

Spector’s colleague at King’s, Dr Claire Steves, points out: ‘The ACE2 receptor that Sars-CoV-2 uses to infect the body is present not only on the surface of the respiratory cells, but also on the cells of many organs that produce hormones, including the thyroid, adrenal glands and ovaries.’ And, as it happens, the ACE2 receptor is found on the amygdala, cerebral cortex and brainstem too, which is why even mild Covid-19 infections may have negative long-term effects on the brain. One expert in neuro-degenerative disorders, Gabriel de Erausquin at the University of Texas, recently told of the ordeal of one of his medical residents, a young mother in her thirties. After coming down with Covid, she had the fever and the usual lack of smell and taste. But as the first symptoms subsided, she was left with a complete emotional detachment from her children. ‘It’s very hard to explain that kind of emotional dissociation without having something going on in the amygdala,’ said de Erausquin.

I think back to the weird haunted feeling of having the bug — the rollcall of symptoms, as if the virus was doing its rounds, checking each defence in turn. What if those of us who have recovered and assume we’re in the clear aren’t necessarily OK? What if, horror--story-style, the baddie can still make a comeback? Scans of 200 recovered patients — seemingly healthy people with a mean age of 44 — found signs of significant damage to hearts, lungs and kidneys. Brain scans of people who have had Covid show unexpected lesions. Might many more of us have damage we aren’t aware of, I ask Spector. Might there be another Covid time bomb, not long Covid so much as sleeping Covid, waiting to emerge as we age? ‘Yes,’ says Professor Spector, in his matter-of-fact way, upbeat as ever. ‘It could be that we’ve got not just the long Covid but anyone who had Covid who had headaches and fever might have had some damage in the brain or the gut, we don’t know.’

But into this gloomy fog of unknowing, there is some light. There is some recent suggestion that the vaccine might itself help dampen long Covid effects, and Inspector Spector is already on the case: ‘We are about to ask that question to all long Covid sufferers on the app,’ he says. ‘But anecdotally we’re hearing of more cases that improve after vaccination, which is hopeful.’

There’s another hopeful area too, which brings us back to where it all began, with the Zoe app, and the microbiome — all the microbes — bacteria, fungi, protozoa and viruses — that live inside the gut. ‘On average, it looks like Covid affects people on poor diets, and we’ve got some early suggestions that poor diet affects severity, so I think it makes sense that the gut micro-biome is going to be key to this,’ says Spector. Do you see places like America, for example, suffer more forms of long Covid as a result of eating more processed food? I ask. ‘Not just America,’ he says, sharply. ‘Britain too. But we can change our microbiome, and the way to do it is through diet.’

If Professor Spector’s right, perhaps the gut contains the answer to another Covid mystery. Though the infection rate in India has been high, its death rate — even among the elderly — has been bafflingly low, and the last best guess as to why — a milder strain of the disease — looks unlikely after further research. Might the gut microbes play a part? ‘Yes,’ says Spector, ‘I think the lower fatality rates may well be due to gut health in places like Africa and India.’ Only time, and the ongoing Covid Symptom Study tracker app, will tell.