Long COVID symptoms and pandemic’s aftermath: What we know now

Excessive amounts of cortisol may lead to Cushing’s syndrome, which causes patients to feel fatigue and have trouble sleeping. (Photo: iStock/imtmphoto)
COVID-19’s devastating toll is often measured by hospitalisations and deaths, but the effects of the pandemic run far deeper and wider.
Some patients raised the alarm over persistent, often debilitating symptoms within months of its emergence.
Other consequences, such as increased rates of dementia and heart disease, could surface years or decades from now according to early findings - similar to how smokers are at increased risk for cancer and cardiovascular disease later in life.
The impact has extended beyond the direct effects of the coronavirus as well.
Stay-at-home orders and other measures aimed at slowing the contagion’s spread led to postponed medical care and socioeconomic disruption that worsened physical and mental health in hard-to-quantify ways.
These all mean that even though COVID-19 is no longer a global public health emergency, its legacy will be felt for a long time.
WHAT IMPACT ON HEALTH HAS COVID-19 HAD?
Most people who contracted SARS-CoV-2, the coronavirus that causes it, fully recovered after mild or even no symptoms. Many didn’t, though, triggering a crisis not witnessed since the 1918-19 Spanish influenza pandemic.
An estimated 15 million additional deaths occurred globally in the first two years of the pandemic alone, including some that were the result of overburdened health systems.
The US saw its biggest two-year decline in life expectancy in a century.
For those who were critically ill and survived, an estimated three out of four developed post-intensive care syndrome - a constellation of brain, lung and other physical problems.
Even for patients who weren’t hospitalised, COVID-19 increased the risk of diabetes and autoimmune diseases, sensory problems and organ damage. Pregnant women face additional risks and so do newborns, especially boys.
Persistent health issues experienced by some patients, often termed long COVID-19, have been described as the pandemic after the pandemic because of the number of people affected - at least 65 million based on a conservative, estimated incidence of 10 per cent of more than 651 million documented cases worldwide.
WHAT ABOUT INDIRECT EFFECTS?
The COVID-19 crisis disrupted the well-being, jobs and incomes of people around the world. Economic activity contracted in 90 per cent of countries and global poverty increased for the first time in a generation, according to the World Bank’s 2022 report.
Health systems were stretched to their limits and beyond, disrupting routine services from cancer screening to obstetrics.
The pandemic exposed health-system frailties and inequalities, and exacerbated a skills shortage among health workers.
Those factors narrowed immunisation coverage, enabling deadly diseases like polio to proliferate, and increased deaths from tuberculosis and malaria.
The unprecedented stress caused by social isolation and precarious employment contributed to a 25 per cent increase in the global prevalence of anxiety and depression in the first year of the pandemic. That period also saw a spike in homicides in US cities even though the overall crime rate was down.
HOW HAVE CHILDREN COPED?
School closures are estimated to have affected 95 per cent of the world’s student population, making it one of the biggest disruptions to learning in history.
That combined with remote learning, illness and quarantines caused youth to lose more than a third of a school year’s worth of learning, according to a meta-analysis published in the journal Nature Human Behavior.
It has resulted in students falling behind in their grade level, greater difficulty doing schoolwork - and more teen pregnancy. Less physical activity and more screen time led to more children being overweight or obese and higher incidences of nearsightedness.
Unicef reported almost 67 million globally missed out on routine vaccinations.
Protective measures that kept kids away from each other hampered the way pediatric immune systems are typically trained.
Once the restrictions began easing, numerous viral epidemics followed, including a deadly liver disease that for some required a transplant.
Pandemic-related sleep disruptions, stress and anxiety triggered a jump in mental health-related hospitalisations and a surge in suspected suicide attempts and drug overdoses.
WHERE DO THINGS STAND WITH LONG COVID?
Long COVID is a loosely defined umbrella term to describe new, returning or ongoing health problems of varying severity that occur after a case of symptomatic or asymptomatic infection with the virus.
Some common ones include coughing or feeling short of breath, loss of smell or change in taste, fever, body aches, trouble sleeping or concentrating, mood changes and digestive problems.
There aren’t any diagnostic tests or biomarkers for long COVID, though doctors may look for abnormalities in tests of cerebral blood flow, some immune cells and levels of reactivated virus.
All the uncertainty makes the condition perplexing and the subject sometimes of skepticism and scorn, and has led some of those afflicted to experience stigma, medical gaslighting and difficulty obtaining disability benefits.
WHAT ARE THE PROSPECTS FOR RECOVERY?
Researchers in Paris found more than 90 per cent of adult long COVID patients gradually recovered over two years, according to an analysis of data from 2,197 patients published in May in the International Journal of Infectious Diseases.
However, longer-term effects are still unfolding and may not be fully realised for decades because of their link with conditions such as diabetes and cardiovascular disease as well as Alzheimer’s and Parkinson’s.
A study published in 2022 in the journal JAMA Neurology found survivors older than 60 were more likely than their uninfected counterparts to experience cognitive decline a year after hospital discharge - signaling a potential COVID-induced increase in the global dementia burden.
WHAT CAUSES LONG COVID?
In some cases, there may be multiple drivers.
Problems can result from the direct effect of the virus on organs and tissues, such as its propensity to cause bleeding and clots in the lungs, or damage caused by the body attacking healthy tissues mistakenly seen as foreign. Some cases have involved a reactivation of Epstein-Barr virus and other herpes viruses that persist after an infection.
Other potential triggers include a lack of oxygen in the blood, an imbalance in the microorganisms inhabiting the gastrointestinal tract, or deleterious effects of life-saving treatments, including the use of mechanical ventilation, corticosteroids, sedatives and painkillers administered in intensive care.
As researchers strive to understand the condition, resemblances to other ailments are coming into focus and providing insight into causes and treatments.
Some people, for example, experience a rapid heartbeat and dizziness after standing up - signs they may have a condition called POTS, or postural orthostatic tachycardia syndrome.
POTS can occur because of a malfunction in the autonomic nervous system, which controls heart rate, body temperature and other involuntary responses.
Others feel an overwhelming exhaustion after physical or mental exertion - a kind of energy crash - that resembles chronic fatigue syndrome, or ME/CFS. People who have chronic fatigue often say it began with a flu-like illness, leading researchers to believe an acute viral infection could be a trigger.
WHAT ARE THE RISK FACTORS FOR LONG COVID?
Several conditions were significantly associated with a higher risk for long COVID, according to a 2023 meta-analysis: being female, overweight, a smoker, having pre-existing co-morbidities, and previous hospitalization or ICU admission. Age was a factor, with the risk lower for younger people.
Studies have found the proportion of new cases has declined with the rising level of vaccinations and previous infections, as well as the circulation of subvariants that are associated with less severe disease.
Other research has pointed to the risk increasing the more times an individual has been infected. Socioeconomic deprivation, belonging to certain ethnic groups, or being bisexual or transgender also put individuals at an increased risk. Some studies have found taking the antiviral treatments Paxlovid and molnupiravir, and the diabetes drug metformin for an acute bout of COVID-19 reduce the risk of long COVID.
WILL WE HAVE TO KEEP GETTING VACCINATED?
It’s uncertain. As of March this year, the World Health Organization recommends getting vaccinated and staying up to date with booster doses generally as a way of preventing Covid and post-acute conditions.
But the agency also supports prioritising the shots for individuals at risk of severe disease - mostly older adults and those with underlying conditions - recommending a booster 6-to-12 months after the last dose, depending on age and other risk factors.
The US Centers For Disease Control and Prevention issued its own guidelines in May, recommending everyone over the age of 6 get the updated vaccines from from either Moderna or the Pfizer-BioNTech partnership.
The WHO said its vaccine recommendations were made in response to prevailing conditions, which may change, and don’t imply annual boosters will be needed.
Meanwhile, with the end of the COVID-19 emergency, free, government-provided booster shots for all are coming to an end in many places, which could contribute to a drop-off in uptake.
WHAT ARE THE ECONOMIC CONSEQUENCES?
Already long COVID has sapped labor participation and increased medical spending.
The US government estimated in late 2022 that it was keeping roughly 1 million people out of the workforce at any given time - costing about US$50 billion a year in lost salaries.
The Institute for Fiscal Studies in the UK estimated in mid-2022 that about 1 in 10 people who develop long Covid stop working, with sufferers generally going on sick leave.
Chronic fatigue leaves at least a quarter of sufferers bed- or house-bound for long periods, and people who’ve had it for at least four years have less than a 4 per cent chance of recovery, according to Solve ME/CFS, a Los Angeles-based nonprofit.
Before the pandemic, 1.5 million Americans had the syndrome, costing US$36 billion to US$51 billion annually in treatment and lost productivity, researchers at DePaul University estimated in 2022. They forecast that Covid could raise the prevalence to between 5 million and 9 million, driving those costs as high as US$362 billion.