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Fitbits Detect Lasting Modifications After Covid-19

Fitbits Detect Lasting Changes After Covid-19

Last spring, when the nation’s Covid-19 cases were soaring and tests were in short supply, some scientists wondered whether a new approach to disease surveillance might be on Americans’ wrists.

One in five Americans uses a Fitbit, Apple Watch or other wearable fitness tracker. And over the past year, several studies have suggested that the devices — which can continually collect data on heart rates, body temperature, physical activity and more — could help detect early signs of Covid-19 symptoms.

Now, research suggests that these wearables can also help track patients’ recovery from the disease, providing insight into its long-term effects.

In a paper published on Wednesday in the journal JAMA Network Open, researchers studying Fitbit data reported that people who tested positive for Covid-19 displayed behavioral and physiological changes, including an elevated heart rate, that could last for weeks or months. These symptoms lasted longer in people with Covid than in those with other respiratory illnesses, the scientists found.

“This was an interesting study, and I think it’s important,” said Dr. Robert Hirten, a gastroenterologist and wearables expert at the Icahn School of Medicine at Mount Sinai who was not involved in the new work. “Wearable devices offer an ability for us to be able to monitor people unobtrusively over long periods of time to see in an objective way — how really has the virus affected them?”

The results are from the Digital Engagement and Tracking for Early Control and Treatment (DETECT) trial run by scientists at the Scripps Research Translational Institute in La Jolla, Calif. From March 25, 2020 to Jan. 24, 2021, more than 37,000 people enrolled in the trial.

Participants downloaded the MyDataHelps research app and agreed to share data from their Fitbit, Apple Watch or other wearable device. They also used the app to report illness symptoms and the results of any Covid-19 tests.

In October, the same researchers reported in Nature Medicine that when they combined wearable data with self-reported symptoms, they could detect Covid-19 cases more accurately than when they analyzed symptoms alone.

But the data, the researchers realized, could also help them track what happened to people after the worst of the illness had passed. People recovering from Covid have reported a wide range of lasting health effects, including fatigue, “brain fog,” shortness of breath, headache, depression, heart palpitations and chest pain. (These lingering effects are often known as long Covid.)

The new study focuses on a subset of 875 Fitbit-wearing participants who reported a fever, cough, body aches or other symptoms of a respiratory illness and were tested for Covid-19. Of those, 234 people tested positive for the disease. The rest were presumed to have other kinds of infections.

Participants in both groups slept more and walked less after they got sick, and their resting heart rates rose. But these changes were more pronounced in people with Covid-19. “There was a much larger change in resting heart rate for individuals who had Covid compared to other viral infections,” said Jennifer Radin, an epidemiologist at Scripps who leads the DETECT trial. “We also have a much more drastic change in steps and sleep.”

The scientists also found that about nine days after participants with Covid first began reporting symptoms, their heart rates dropped. After this dip, which was not observed in those with other illnesses, their heart rates rose again and remained elevated for months. It took 79 days, on average, for their resting heart rates to return to normal, compared with just four days for those in the non-Covid group.

Updated 

July 7, 2021, 1:59 p.m. ET

This prolonged heart rate elevation may be a sign that Covid-19 disrupts the autonomic nervous system, which regulates basic physiological processes. The heart palpitations and dizziness reported by many people who are recovering from Covid may be symptoms of this disruption.

“Lots of people who get Covid end up getting autonomic dysfunction and a kind of ongoing inflammation, and this may adversely affect their body’s ability to regulate their pulse,” Dr. Radin said.

Sleep and physical activity levels also returned to baseline more slowly in those with Covid-19 compared to those with other ailments, Dr. Radin and her colleagues found.

The researchers identified a small subset of people with Covid whose heart rates remained more than five beats per minute above normal one to two months after infection. Nearly 14 percent of those with the disease fell into this category, and their heart rates did not return to normal for more than 133 days, on average.

These participants were also significantly more likely to report having had a cough, shortness of breath and body aches during the acute phase of their illness than did other Covid patients.

One limitation of the study is that it did not ask participants to continue reporting their symptoms in the weeks and months after they first fell ill. But the scientists are planning to ask volunteers to do that in future research.

“We want to kind of do a better job of collecting long-term symptoms so we can compare the physiological changes that we’re seeing with symptoms that participants are actually experiencing,” Dr. Radin said. “So this is really a preliminary study that opens up many other studies down the road.”

In February, the National Institutes of Health announced that it would provide $1.15 billion over the next four years to fund research on long Covid. The new study highlights the role that wearables could play in that research, Dr. Hirten said: “Combining these sort of techniques with other studies that are being done looking at this issue of long-term symptoms could really offer a nice objective insight into what’s going on with people.”

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Pfizer and Moderna Vaccines Prone to Produce Lasting Immunity, Research Finds

Pfizer and Moderna Vaccines Likely to Produce Lasting Immunity, Study Finds

The vaccines from Pfizer-BioNTech and Moderna trigger a sustained immune response in the body that can protect against the coronavirus for years, scientists reported on Monday.

The results add to the growing evidence that most people immunized with the mRNA vaccines may not need a booster dose as long as the virus and its variants do not progress much beyond their current forms – which is not guaranteed. People who have recovered from Covid-19 before they were vaccinated may not need a booster vaccination, even if the virus goes through a significant transformation.

“It’s a good sign of how persistent our immunity to this vaccine is,” said Ali Ellebedy, an immunologist at Washington University in St. Louis who led the study, which was published in the journal Nature.

The study did not take into account the coronavirus vaccine manufactured by Johnson & Johnson, but Dr. Ellebedy said he believed the immune response was less permanent than that of mRNA vaccines.

Dr. Ellebedy and colleagues reported last month that in people who survived Covid-19, immune cells that recognize the virus remain dormant in the bone marrow for at least eight months after infection. A study by another team showed that so-called memory B cells continue to mature and strengthen for at least a year after infection.

Based on these results, the researchers suggested that immunity in people infected with the coronavirus and later vaccinated could last for years, possibly a lifetime. However, it was unclear whether vaccination alone could have a similar long-lasting effect.

Dr. Ellebedy addressed this question by examining the source of memory cells: the lymph nodes, where immune cells train to recognize and fight the virus.

After an infection or vaccination, a specialized structure forms in the lymph nodes, the germinal center. This structure is sort of an elite school for B cells – a boot camp in which they become increasingly sophisticated and learn to recognize a multitude of viral genetic sequences.

The greater the range and the longer these cells have to practice, the more likely they are to thwart any virus variants that may appear.

“Everyone is always focused on developing the virus – this shows that the B cells are doing the same,” said Marion Pepper, an immunologist at the University of Washington in Seattle. “And it will protect against the continued development of the virus, which is really encouraging.”

After an infection with the coronavirus, the germinal center forms in the lungs. But after the vaccination, the cells are formed in the lymph nodes in the armpits that researchers can reach.

Updated

July 2, 2021, 5:06 p.m. ET

Dr. Ellebedy and colleagues recruited 41 people – including eight with a history of infection with the virus – who were immunized with two doses of the Pfizer BioNTech vaccine. The team collected lymph node samples from 14 of these people three, four, five, seven and 15 weeks after the first dose.

This meticulous work makes this a “heroic study,” said Akiko Iwasaki, an immunologist at Yale. “This kind of careful time history analysis in humans is very difficult.”

Dr. Ellebedy found that 15 weeks after the first dose of the vaccine, the germinal center was still highly active in all 14 participants and that the number of memory cells that recognized the coronavirus had not decreased.

“The fact that the reactions lasted almost four months after the vaccination – that’s a very, very good sign,” said Dr. Ellebedy. Sprouting centers typically peak one to two weeks after vaccination and then decrease.

“Usually there isn’t much left after four to six weeks,” said Deepta Bhattacharya, an immunologist at the University of Arizona. But germinal centers that are stimulated by the mRNA vaccines “still go in, months, and most people don’t go back much”.

Dr. Bhattacharya noted that most of what scientists know about the persistence of germinal centers is based on animal studies. The new study shows for the first time what happens to people after vaccination.

The results suggest that the vast majority of those vaccinated will be protected in the long term – at least against the existing coronavirus variants. But older adults, people with weak immune systems, and those taking drugs that suppress immunity may need boosters; People who survived Covid-19 and were later vaccinated may not need it at all.

It is difficult to predict exactly how long protection against mRNA vaccines will last. In the absence of variants that bypass immunity, immunity could theoretically last a lifetime, experts said. But the virus is clearly evolving.

“Anything that would actually require a refresher would be variant-based, not immunity waning,” said Dr. Bhattacharya. “I just don’t see it.”

People who have been infected with the coronavirus and then immunized see a sharp spike in their antibody levels, likely because their memory B cells – which produce antibodies – had many months to develop before vaccination.

The good news: a booster vaccine is likely to have the same effect on people who have been vaccinated as a previous infection, said Dr. Ellebedy. “If you give them another chance to get involved, they’ll have a massive response,” he said, referring to memory B cells.

In terms of boosting the immune system, vaccination is “probably better” than recovering from the actual infection, he said. Other studies have shown that the repertoire of memory B cells produced after vaccination is more diverse than that produced by infection, suggesting that the vaccines protect against variants better than natural immunity alone.

Dr. Ellebedy said the results also suggest that these signs of sustained immune response could be caused by mRNA vaccines alone, as opposed to those made by more traditional means like Johnson & Johnson’s.

But that’s an unfair comparison because the Johnson & Johnson vaccine is given as a single dose, said Dr. Iwasaki: “If the J&J had a booster, they might get the same kind of reaction.”

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Medical specialists attempt to set up ‘lengthy Covid’ analysis for sufferers with lasting signs

Medical experts try to establish 'long Covid' diagnosis for patients with lasting symptoms

Critical care carers insert an endotracheal tube into a patient with coronavirus disease (COVID-19) in the intensive care unit (ICU) at Sarasota Memorial Hospital in Sarasota, Florida on February 11, 2021.

Shannon Stapleton | Reuters

Some Covid-19 patients suffer from shortness of breath, fatigue, headaches and “brain fog” for months to almost a year after their first illness. Now global medical experts are working to better diagnose and treat what they tentatively refer to as “long covid”.

Earlier this week, the World Health Organization hosted a global meeting with “patients, clinicians and other stakeholders” to improve the agency’s understanding of the post-Covid medical condition, also known as Long Covid, WHO director general Tedros Adhanom Ghebreyesus said Friday.

The meeting was the first of many to come. The goal will ultimately be to produce an “agreed clinical description” of the disease so that doctors can diagnose and treat patients effectively, he said. Given the number of people infected with the virus worldwide – nearly 108 million people as of Friday – Tedros warned that many of these persistent symptoms are likely to appear.

“This disease affects patients with severe and mild Covid-19,” Tedros said during a press conference at the agency’s headquarters in Geneva. “Part of the challenge is that long-term Covid patients can have a range of different symptoms that can be persistent or come and go.”

Limited dates

So far, there have been a limited number of studies that will determine what symptoms are most common and how long they might last. The main focus was on people with a serious or fatal illness, not people who have recovered but still report persistent side effects, sometimes referred to as “long distance riders”.

Most Covid patients are believed to recover only weeks after their initial diagnosis, but some have symptoms for six months or even almost a year, medical experts say.

One of the largest global studies on Long Covid, published in early January, found that many people who have persistent illness after infection cannot work full-time six months later. The study, published on MedRxiv and not peer reviewed, interviewed more than 3,700 people, ages 18 to 80, from 56 countries to identify symptoms.

The most common symptoms after six months were fatigue, post-exercise fatigue, and cognitive dysfunction, sometimes called brain fog.

Is that unique to Covid-19?

“We really don’t know what is causing these symptoms. That is a focus of research right now,” said Dr. Allison Navis, a professor at the Icahn School of Medicine at Mount Sinai, during a call to the Infectious Diseases Society of America on Friday.

“The question that arises is whether this is something that is unique to Covid itself – and it is the Covid virus that is causing these symptoms – or whether this could be part of a general post-viral syndrome,” Navis said, adding, that medical experts see similar long-term symptoms after other viral infections.

Another study, published in the medical journal The Lancet in early January, looked at 1,733 patients discharged from a hospital in Wuhan, China, between January and May last year. Of these patients, 76% reported at least one symptom six months after their first illness. The proportion was higher among women.

“We found that fatigue or muscle weakness, sleep disorders, and anxiety or depression were common even 6 months after symptoms appeared,” the researchers wrote in the study.

They found that symptoms reported months after the Covid-19 diagnosis was consistent with data previously found in follow-up studies of Severe Acute Respiratory Syndrome (SARS), a coronavirus.

Post-Covid clinics are going online

Some large medical centers are currently setting up post-Covid clinics to care for patients with persistent symptoms. Navis said her clinic on Mount Sinai, New York treated a “fairly even” distribution of men and women with persistent illness, and the average age of patients was 40 years.

Dr. Kathleen Bell, a professor at the University of Texas’ Southwestern Medical Center, said her hospital’s long-term Covid-19 clinic began last April when a wave of infections hit Italy and New York at the start of the pandemic.

Bell said on the Infectious Diseases Society of America conference call on Friday that a number of professionals are required to staff the clinics because symptoms are uneven, including experts who can treat muscle weakness, heart-related disorders, and cognitive problems in the insane and health Problems after their diagnosis.

“It forces all of us, in many ways, to come together and make sure we have open lines of communication to address all of these issues for patients,” said Bell.

Bell added that the Centers for Disease Control and Prevention held a phone call in January with long Covid centers across the country to discuss their model for treating patients.

“I think the CDC is now trying to bring centers together and get some firmer guidelines on it, which is very exciting,” said Bell.

– CNBC’s Sam Meredith contributed to this report.