CHICAGO: When COVID-19 hit in 2020, Ghenya Grondin of Waltham, Massachusetts, was a postpartum doula - a person charged with helping young couples navigate the first weeks of their newborn child's life at home.

Grondin, now aged 44, was infected with SARS-CoV-2 in mid-March of that year - before there were tests, before social distancing or masks, and many months before the medical community recognized long COVID as a complication of COVID-19.

She is part of a community of first-wave long-haulers who faced a new disease without a roadmap or support from the medical establishment.

Three years later, at least 65 million people worldwide are estimated to have long COVID, according to an evidence review published last month in Nature Reviews Microbiology. More than 200 symptoms have been linked to the syndrome - including extreme fatigue, difficulty thinking, headaches, dizziness when standing, sleep problems, chest pain, blood clots, immune dysregulation, and even diabetes.

There are no proven treatments but research is underway.

People infected later in the pandemic had the benefit of vaccination, which "protects at least to some degree" from long COVID, said Dr. Bruce Levy, a Harvard pulmonologist and a co-principal investigator of the National Institute of Health's $1.15 billion U.S. RECOVER trial, which aims to characterize and find cures for the disease.

"The initial variant of the virus caused a more severe illness than we're seeing currently in most patients," he said.

According to the University of Washington's Institute of Health Metrics and Evaluation, in the first two years of the pandemic women were twice as likely as men to develop long COVID, and 15% of all of those affected at three months continued to experience symptoms beyond 12 months.

An analysis of thousands of health records by the RECOVER trial found that non-Hispanic white women in wealthier areas were more likely than others to have a long COVID diagnosis. Researchers said that likely reflected disparities in access to healthcare, and suggests that many cases of long COVID among people of color are not being diagnosed.

Grondin grew concerned when she continued to have symptoms three months after her initial infection - but there was no name for it then.

"I just kept saying to my husband, something isn't right," she said.

Like her fellow long-haulers, she has experienced a host of symptoms, including fatigue, sleep apnea, pain, cognitive dysfunction, and in her case, a brain aneurysm. She described a frightening moment when she was driving a car with her toddler in the back and had a seizure that left her in the path of oncoming traffic.

She has since been diagnosed with long COVID and can no longer work.

"It just feels like a constant punch in the face," said Grondin.

Scientists are still working out why some people infected with COVID develop long-term symptoms, but syndromes like this are not new. Other infections such as Lyme disease can result in long-term symptoms, many of which overlap with long COVID.

Leading theories of the root causes of long COVID include the virus or viral proteins remaining in the tissues of some individuals; the infection causing an autoimmune response; or the virus reactivating latent viruses, leading to inflammation that damages tissue.

Kate Porter, 38, of Beverly, Massachusetts, a project manager for a financial services company, believes she was infected on a flight back from Florida in late March of 2020.

She had daily fevers for seven months, muscle weakness, shortness of breath, and excruciating nerve pain.

"I don't think people realize how brutal physically everything was," she said. In one of her darker moments, Porter recalled, "I cried on the floor begging for something to take me peacefully. I've never been like that."

Frustrated by the lack of answers from a list of 10 specialists she has seen, Porter has explored alternative medicine. "It has opened me up to other remedies," she said.

Although her health is much improved now, she still suffers from near daily migraines and neck pain she fears may never go away.

Genie Stevens, 65, a director of climate education, got infected while traveling from her home in Santa Fe to Cape Cod in late March 2020 to visit her mother, and never left. "It completely upended my life," she said.

She went to an emergency department seeking tests and was told there were none - the typical answer in the spring of 2020, when scientists were scrambling to understand the nature of the virus and tests were being rationed. She was sent home to manage on her own.

A lifelong practitioner of meditation, Stevens took solace there, finding it eased her symptoms.

Confined to her bed that spring, she focused on an ancient crabapple tree outside her room. "I watched every bud unfurl."

Although largely recovered, Stevens still has flare-ups of brain fog, exhaustion and high-pitched ringing in her ears when she pushes too hard. "This is the astoundingly maddening part of the illness. I feel totally fine, and then bam."