When Katie Lazell-Fairman returned to work after recovering from a Covid-19 infection, she quickly discovered that the virus had taken a much heavier toll on her body than she initially realised.

“I woke up suddenly feeling incredibly exhausted, dizzy. My heart rate was 135 beats per minute standing, 140-150 walking,” says the 35-year-old, a data scientist from New York. “I couldn’t think straight and struggled to code on my laptop.”

Lazell-Fairman, who caught Covid during the city’s first wave in 2020, says she had to quit a contract job and stop working on a start-up she founded to develop software for art collectors. Her doctor diagnosed her with a blood circulation disorder and other Covid-related conditions, which left her bedridden on some days and housebound on others.

Eighteen months later, Lazell-Fairman still cannot work or return to her favourite pastimes, swing dancing and hiking. Her application for social security disability benefits was recently rejected by authorities. She has given up her New York apartment and moved in with her mother-in-law. “Covid took away my career, financial independence and ability to look after myself,” she says.

Lazell-Fairman is one of an estimated 100mn people worldwide suffering from long Covid, a debilitating condition where Covid symptoms linger for 12 weeks or more, frequently leaving them unable to return to their previous working lives.

Sufferers report a wide array of symptoms. Breathlessness and heart palpitations are common, as are gastrointestinal problems, extreme fatigue and crippling insomnia. Some experience tinnitus, tremors, nerve pain or sensitivity to noise and light.

Others suffer lasting neurological and cognitive effects that are less visible, but equally disabling. Many suffer from depression or anxiety or “brain fog”, struggling with memory, concentration and making decisions.

“My cognitive ability is nowhere near where it used to be,” says Alison Twycross, a former nursing practitioner and lecturer in the UK who fell ill in March 2020. “On a good day I can work two hours in the morning and two hours in the afternoon. I sleep in the middle.”

While long Covid is taking a heavy toll on the individuals affected, it also represents a disaster in the making for businesses and economies — potentially pushing significant numbers of people out of labour markets where employers are already struggling to hire.

One in five patients hospitalised with Covid were still not working five months later, according to a UK study on the effects of the virus post-hospitalisation. A similar proportion had changed their job because of health issues.

Twycross was unable to return to her job and has had to hire an assistant to help her with the book she is editing. “I can’t do attention to detail so I employed someone to check my chapters and I’m so behind,” she says.

Policymakers are starting to suspect the condition is a factor behind the labour shortages seen in the US and UK, where many older workers are looking to work fewer hours or have left the workforce completely. One study by the Brookings Institution in January speculated that long Covid could potentially account for upwards of 15 per cent of the 10.6mn unfilled jobs in the US.

“It doesn’t matter whether you drive the truck, you work the cash register at McDonald’s or you run a Fortune 500 company. You can’t go back to any of those jobs with cognitive dysfunction,” says Diana Berrent, founder of Survivor Corps, a long Covid support group in the US.

The condition is so new that employment law has yet to catch up with it: in many countries, governments and courts have not yet made clear to what extent it should be treated as a disability or an occupational disease. On April 5, the Biden administration said it would scale up national research on long Covid, and directed federal agencies to support sufferers as they seek treatment and attempt to return to work.

But in the meantime, activists say employers need to recognise not just their own responsibilities but also the potential impact on their businesses. “We are talking about . . . people who are in the prime of their lives, who are also at the prime of their earning potential,” Berrent says.

A crunch point looms

So far, the scale of the problem globally is unknown: very few countries collect data on the incidence of long Covid, and employers are not always aware of cases among their staff, who often struggle to get a diagnosis, or are reluctant to disclose their condition for fear it will affect their position.

But in some countries, labour market data give an idea of how long-term health issues grew during the pandemic. In the US, where long Covid can qualify as a disability under the Americans with Disabilities Act, labour force data show the number of civilians with a disability who are working or seeking work grew by 1.36mn, a 23 per cent increase, between January 2021 and January 2022.

Meanwhile, UK labour market data show a rise of some 200,000 since the start of the pandemic in the number of people who are not working or job-seeking because of long-term ill health; and a quarter of UK companies say long Covid is one of the main causes of long-term staff absence.

The UK also publishes an official monthly count of self-reported cases, in which an estimated 1.2mn people said in March they had persistent long Covid symptoms lasting at least 12 weeks, with women, people aged between 35 and 49, health workers and teachers most affected. A total of 784,000 said they had been suffering for at least a year, and 322,000 said it limited their day to day activities “a lot.”

“I think we’re in for a much bigger problem,” says Clare Rayner, a former consultant occupational physician afflicted by long Covid, who is helping to develop services for sufferers.

She believes the numbers affected will become more visible as businesses ask staff to return to offices and as some NHS employers, who have so far kept health workers on full pay while on Covid-related sick leave, withdraw this support.

“There’s a crunch point coming very, very soon,” Rayner says, adding that she was increasingly seeing people being “managed out” if they were unable to return full time.

Twycross, the former lecturer, founded an advocacy group for UK nurses and midwives affected by long Covid and encountered many people who have dropped managerial responsibilities, cut their hours or been forced to resign. What concerns her is “how badly they are treated when they try to return to work,” she says. “They are having to fight to get an extended phased return.”

Research by the UK’s Trades Union Congress found that a quarter of employees with long Covid had not dared tell their employer, while a fifth faced questions about the impact of their symptoms and one in 20 had felt forced to retire, resign or take redundancy. “We have a significant workplace issue, a growing issue,” says Sue Coe, TUC senior policy officer.

Businesses need to be giving “massive support and tailored advice” to employees with long Covid, Rayner adds. “If we don’t, these people are going to be on benefits, losing their house. Employers are losing a massive amount of talent. Employers need to look at the big picture.”

The challenge for companies

Some large global companies are now beginning to see the condition as a serious risk to their business.

Stephen Bevan, head of HR research development at the UK’s Institute for Employment Studies, says the issue was “high on the agenda” for the newly influential chief medical officers of large European companies, who had “a direct line of sight between long Covid and lost capacity” and were seeking to intervene early to minimise the cost of covering long-term absences with bank and agency staff.

He was also working with multinationals worried about the potential disruption to their operations in emerging markets such as Brazil and India where Covid had hit hard.

Smaller companies may also be forced to develop policies to address the condition. In the US, where employers must make “reasonable accommodations” to allow a person assessed as having a disability to continue in their jobs, lawyers say lawsuits relating to long Covid are becoming more common as companies ask staff to return to the office.

The US Equal Employment Opportunity Commission received more than 4,000 allegations of disability laws being violated in relation to Covid during 2020 and 2021. Although the agency does not distinguish between Covid and long Covid claims, it published guidance for employers in December to alert them about the issue.

“We are still seeing cases filed that are linked to terminations due to Covid and haven’t yet seen the mother lode of long Covid cases yet,” says Salvatore Gangemi, partner at Murtha Cullina, a US law firm.

Damages awards under discrimination laws could run to millions of dollars, he adds. “I think what the EEOC is doing by issuing guidance is trying to get out in front of this problem. Companies really need to engage or at least attempt to engage with employees who raise these issues.”

While UK courts are yet to rule on the legal status of long Covid, lawyers say many sufferers would have good cases to be treated as disabled, entitling them to reasonable adjustments to help them do their job.

But it will take a concerted effort on the part of employers and policymakers to change HR practices, benefits systems and a workplace culture that currently fails many people with chronic health conditions.

Coe says the “shocking” treatment many employees with long Covid had received was “not surprising, given the broader experience of disabled workers”, who often found employers unwilling to grant flexibility around shift patterns, rest breaks, homeworking or changes to their duties.

Working with the condition

Sufferers of long Covid hoping to return to work have few treatment options, as researchers are only starting to define the condition.

Doctors have experimented with a range of existing drugs while pharmaceutical companies are developing new treatments targeted at symptoms such as muscle fatigue or lung scarring, but none are in phase 3 trials. In the UK and the US, long Covid clinics offer mental healthcare and physiotherapy, but waiting lists are long.

Working with the condition is further complicated by its unpredictable nature: symptoms vary wildly and fluctuate unexpectedly, with many sufferers finding even mild exertion brings on a relapse.

This means that standard HR policies — which offer employees a “phased return” to their usual hours and duties, typically over a four-week period — set people up to fail, as do “absence management” policies that often seem designed to catch malingerers, not to support those genuinely struggling.

Jenny Ceolta-Smith, an occupational therapist who suffers from long Covid, says she tried twice to return to her job as a lecturer but found it impossible, even after paying privately for help with fatigue management. “I typically try to go out for a short walk once a week, it might be around the block or a little longer . . . At times I’m completely wiped out,” she says.

Her employer was willing to cut her hours, but not for her to work purely from home: she eventually felt she had no option but to agree to leave and later claim benefits. She has since taken a position as an associate lecturer, working a few hours a week from home.

“Your hope is diminished a little bit each time,” says Lesley Macniven, a consultant and long Covid campaigner, who suffered a “massive relapse” recently after being asked to deliver a training session in a community library that she had previously been running online. “The process of getting there and back really knocked me for six . . . It’s one job but it’s a job I really value and don’t want to lose,” she says.

Occupational health professionals say long Covid sufferers should not be placed on protracted sick leave, since long periods of worklessness are also damaging. Instead, they should be allowed to return at a far more gentle, gradual pace, with adjustments tailored to their specific circumstances and co-ordinated support from HR, line managers and colleagues.

“As with cancer, it’s very much a collective effort to get people back to work,” says Veronica Swainson, who has led a specialist work rehabilitation programme for staff at the King’s College Hospital NHS Foundation Trust in London — one of the hardest hit in the pandemic’s first wave — which has helped about 130 of a 13,000-strong workforce since the summer of 2020.

People typically take about three months to build back up to their usual hours while on full pay, Swainson says, but the type of support offered varies widely. Someone suffering from fatigue might receive cab vouchers to avoid an exhausting commute, while a senior manager struggling to multitask might be given an assistant to help plan their day.

Anne de Bono, a consultant in occupational medicine who sits on the NHS long Covid task force, says special care was needed for workers in safety-critical roles, citing the case of a surgeon at her hospital who had been given a “trusted buddy” to work with as he regained his confidence.

But this kind of intensive support is exceptional, even within the NHS, which is acutely aware of the risk long Covid poses to its own strained workforce. In some countries — Japan and the Netherlands among them — employers must take responsibility for staff who fall sick. In the UK, however, long-term sick pay is rare, as is access to occupational healthcare, and even if staff are covered by insurance schemes, insurers can be unwilling to pay. In the US, federal law does not require businesses to offer any sick pay at all, though some states, cities and counties do.

Yet if employers rise to the challenge long Covid represents, they stand to gain — while helping people who have spent the past two years fighting to regain their health and livelihood to relaunch their careers. “Life changes — the person has to adapt to the condition. But their recovery is positive over time. They return to some kind of normality,” Swainson says.

Lazell-Fairman is hopeful medical research will produce new treatments that can help long Covid sufferers get back to work. But she says a more supportive framework from both employers and health authorities is required to deal with the huge numbers of sufferers.

“It’s a pandemic. It’s a very extraordinary circumstance. So I’m just thinking, there must be something they can do to make things easier for people,” she says.

Additional reporting by Hannah Kuchler in London