Tag Archives: reinfection

WHO sounds warning over fast-spreading Omicron

By Stephanie Nebehay and Emma Farge

GENEVA (Reuters) -The Omicron variant of the coronavirus is spreading faster than the Delta variant and is causing infections in people already vaccinated or who have recovered from the COVID-19 disease, the head of the World Health Organization (WHO) said on Monday.

WHO chief scientist Soumya Swaminathan added it would be “unwise” to conclude from early evidence that Omicron was a milder variant that previous ones.

“… with the numbers going up, all health systems are going to be under strain,” Soumya Swaminathan told Geneva-based journalists.

The variant is successfully evading some immune responses, she said, meaning that the booster programs being rolled out in many countries ought to be targeted towards people with weaker immune systems.

“There is now consistent evidence that Omicron is spreading significantly faster than the Delta variant,” WHO director-general Tedros Adhanom Ghebreyesus told the briefing.

“And it is more likely people vaccinated or recovered from COVID-19 could be infected or re-infected,” Tedros said.

Their comments echoed the finding of study by Imperial College London, which said last week the risk of reinfection was more than five times higher and it has shown no sign of being milder than Delta.

WHO officials said however that other forms of immunity vaccinations may prevent infection and disease.

While the antibody defenses from some actions have been undermined, there has been hope that T-cells, the second pillar of an immune response, can prevent severe disease by attacking infected human cells.

WHO expert Abdi Mahamud added: “Although we are seeing a reduction in the neutralization antibodies, almost all preliminary analysis shows T-cell mediated immunity remains intact, that is what we really require.”

However, highlighting how little is known about how to handle the new variant that was only detected last month, Swaminathan also said: “Of course there is a challenge, many of the monoclonals will not work with Omicron.”

She gave no details as she referred to the treatments that mimic natural antibodies in fighting off infections. Some drug makers have suggested the same.

ENDING THE PANDEMIC

In the short term, Tedros said that holiday festivities would in many places lead to “increased cases, overwhelmed health systems and more deaths” and urged people to postpone gatherings.

“An event cancelled is better than a life cancelled,” he said.

But the WHO team also offered some hope to a weary world facing the new wave that 2022 would be the year that the pandemic, which already killed more than 5.6 million people worldwide, would end.

It pointed towards the development of second and third generation vaccines, and the further development of antimicrobial treatments and other innovations.

“(We) hope to consign this disease to a relatively mild disease that is easily prevented, that is easily treated,” Mike Ryan, the WHO’s top emergency expert, told the briefing.

“If we can keep virus transmission to minimum, then we can bring the pandemic to an end.”

However Tedros also said China, where the SARS-CoV-2 coronavirus was first detected at the end of 2019, must be forthcoming with data and information related to its origin to help the response going forward.

“We need to continue until we know the origins, we need to push harder because we should learn from what happened this time in order to (do) better in the future,” Tedros said.

(Reporting by Stephanie Nebehay and Emma Farge; Editing by Alison Williams)

COVID-19 reinfection less likely to be severe; cardiac stress test useful for unexplained lingering breathlessness

By Nancy Lapid

(Reuters) – The following is a summary of some recent studies on COVID-19. They include research that warrants further study to corroborate the findings and that has yet to be certified by peer review.

Coronavirus reinfections rarely severe

Reinfections with the virus that causes COVID-19 are rarely severe, new findings suggest. Researchers in Qatar compared 1,304 individuals with a second SARS-CoV-2 infection with 6,520 people infected with the virus for the first time. The odds of developing severe disease were 88% lower for people with second infections, the researchers reported online on Wednesday in The New England Journal of Medicine. Re-infected patients were 90% less likely to be hospitalized compared to patients infected for the first time, and no one in the study with a second infection required intensive care or died from COVID-19, said Dr. Laith Jamal Abu-Raddad of Weill Cornell Medicine-Qatar in Doha. “Nearly all reinfections were mild, perhaps because of immune memory that prevented deterioration of the infection to more severe outcomes,” he said. The risk for severe illness in people who had been infected before was only about 1% of the risk associated with initial COVID-19 infections, the researchers estimated. For half of those with a second infection, the first infection had occurred more than nine months earlier. It is not clear how long immune protection against severe reinfection would last, the researchers noted. If it does last for a long time, they speculate, it might mean that as the coronavirus becomes endemic, infections could become “more benign.”

Cardiac stress test useful for lingering breathlessness

In COVID-19 survivors struggling with lingering shortness of breath for which doctors do not have an explanation, cardiac stress testing may help identify the cause of the problem, researchers say. “The current clinical guidelines do not recommend cardiopulmonary exercise testing out of concern that this test could worsen the patients’ symptoms. However, we found that cardiopulmonary exercise testing was able to identify reduced exercise capacity in about 45% of patients,” said Dr. Donna Mancini of the Icahn School of Medicine at Mount Sinai in New York. The 18 men and 23 women in the study all had persistent shortness of breath for more than three months after recovering from COVID-19, according to a report published on Monday in Journal of the American College of Cardiology: Heart Failure. They had normal-looking results on lung function tests, chest X-rays, chest CT scans and echocardiograms. The exercise tests revealed problems that would otherwise have been missed, Mancini said. “Low level functional testing recommended by the guidelines, such as a 6-minute walk test, would not be able to detect these abnormalities,” she said.

Experimental smartwatch COVID-19 detection improving

Smartwatch alerting systems for early detection of COVID-19 infection are coming closer to reality, researchers reported on Monday in Nature Medicine. They tested their new system, developed with open-source software, in 2,155 wearers of Fitbit, Apple Watch, Garmin watches or other devices. Ultimately, 84 of the volunteers were diagnosed with coronavirus infections – including 14 of 18 people without symptoms. Overall, the researchers’ algorithms generated alerts in 67 (80%) of the infected individuals, on average three days before symptoms began. “This is the first time, to our knowledge, that asymptomatic detection has been shown for COVID-19,” they said. Presently, the system mainly depends on measurements of wearers’ resting heart rate, said study leader Michael Snyder of Stanford University School of Medicine in California. Going forward, he said he hopes watch manufacturers will be able to provide other types of highly accurate physiologic data. “Many stressors can trigger the alerting,” Snyder said. “Most of these are easy to spot – travel, excessive alcohol, even work or other types of stress, so the user knows to ignore the alerts.” When watches can report other health data such as heart rate variability, respiration rate, skin temperature, and oxygen levels, it will become easier to distinguish the COVID-19 cases from other non-COVID-19 events, researchers said. “Right now we are running this as a research study,” Snyder said. “But soon we hope that FDA approved devices will dominate this area.”

(Reporting by Nancy Lapid; Additional reporting by Megan Brooks; Editing by Bill Berkrot)

COVID-19 reinfection detected in U.S. patient; saliva tests endorsed

By Nancy Lapid

(Reuters) – The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.

COVID-19 reinfection seen in U.S. patient

A case of coronavirus reinfection has been documented in a U.S. patient from Reno, Nevada, according to doctors. The 25-year-old man tested positive for the virus in April after showing mild illness and then got sick again in late May, developing more severe COVID-19 symptoms. Doctors and Nevada public health officials said they were able to show through sophisticated testing that the virus associated with each instance of infection represented genetically different strains. Their report, released on Friday, is undergoing peer review by the Lancet medical journal. Last week, three reinfections were reported – one in Hong Kong and two in Europe. Unlike the Nevada case, the second infections in those patients were milder than the first. Reinfection “may represent a rare event,” the Nevada researchers wrote. But, they said, the findings implied that initial exposure to the virus may not result in full immunity for everyone who has been infected by it.

Saliva samples preferable for COVID-19 testing

Letting patients provide saliva samples for COVID-19 tests is easier and safer than swabbing the back of the nose and throat for samples to test, and the results are equally reliable, Yale University researchers said. Writing on Friday in the New England Journal of Medicine, they compared saliva and nasopharyngeal swab samples from 70 U.S. hospitalized COVID-19 patients and 495 asymptomatic healthcare workers, using gold-standard laboratory methods. In both groups, the saliva tests and the nasopharyngeal swab tests showed similar sensitivity for detecting the virus. For healthcare workers, unlike the collection of nasopharyngeal samples, collection of saliva samples by patients does not present a risk of infection and alleviates demands for supplies of swabs and personal protective equipment, the researchers said. In a separate study on Friday in the journal Annals of Internal Medicine, Canadian researchers employed an experimental saliva test kit and found that it might miss some mild or asymptomatic infections. But they agreed with the Yale researchers about the advantages of saliva tests and said they “may be of particular benefit for remote, vulnerable or challenging” patients.

Accuracy of faster COVID-19 tests is unclear

It is hard to know whether so-called point-of-care COVID-19 tests, which provide results in a couple of hours rather than days as some other tests do, are accurate, according to a research review. The authors of the review, published on Wednesday by the Cochrane Library, focused on two types of rapid point-of-care tests: antigen tests, which identify proteins on the virus using disposable devices, and molecular tests, which detect viral genetic material using portable or table-top devices. Altogether, they reviewed 22 studies from around the world that compared point-of-care tests to gold-standard so-called RT-PCR laboratory tests. Three-quarters of the studies did not follow the point-of-care test manufacturers’ instructions, they found. There also was little information about study participants, so it was not possible to tell if the results could be applied to people with no symptoms, mild symptoms or severe symptoms. And studies often were at risk for bias, or did not detail their methods. “The evidence currently is not strong enough and more studies are urgently needed to be able to say if these tests are good enough to be used in practice,” the research team led by Jonathan Deeks of the University of Birmingham in Britain wrote.

New studies add to data on COVID-19 in children

Children are far less likely than adults to get severe cases of COVID-19, British doctors found. At 138 hospitals in Britain, through June, less than 1% of COVID-19 patients were children, and 99% survived. Those who died had serious underlying health conditions. “We can be quite sure that COVID in itself is not causing harm to children on a significant scale,” said Malcolm Semple of the University of Liverpool, co-author of research published on Thursday in BMJ. While children’s risk for severe COVID-19 is low, Black children and obese children experienced higher risks. A separate study published on Monday in the journal JAMA Pediatrics suggests the proportion of U.S. children with asymptomatic COVID-19 may be low. At 28 hospitals, more than 33,000 children were tested during ear, nose and throat appointments or procedures. None were suspected of having the virus. Fewer than 1% were asymptomatically infected. Even without symptoms, infected children can shed virus for weeks, Korean doctors said on Friday in the JAMA Pediatrics.

(Reporting by Nancy Lapid, Kate Kelland and Deena Beasley; Editing by Will Dunham)

First U.S. COVID-19 reinfection case identified in Nevada study

By Deena Beasley

(Reuters) – Researchers for the first time have identified someone in the United States who was reinfected with the novel coronavirus, according to a study that has not yet been reviewed by outside experts.

The report, published online, describes a 25-year-old man living in Reno, Nevada, who tested positive for the virus in April after showing mild illness. He got sick again in late May and developed more severe COVID-19, the disease caused by the virus.

Cases of presumed reinfection have cropped up in other parts of the world, but questions have arisen about testing accuracy. Earlier this week, University of Hong Kong researchers reported details of a 33-year-old man who had recovered in April from a severe case of COVID-19 and was diagnosed four months later with a different strain of the virus.

Researchers at the University of Nevada, Reno School of Medicine and the Nevada State Public Health Laboratory said they were able to show through sophisticated testing that the virus associated with each instance of the Reno man’s infection represented genetically different strains.

They emphasized that reinfection with the virus is probably rare, but said the findings imply that initial exposure to the virus may not result in full immunity for everyone.

(Reporting by Deena Beasley; Editing by Dan Grebler)

Monkeys infected with COVID-19 develop immunity in studies, a positive sign for vaccines

By Julie Steenhuysen

CHICAGO (Reuters) – Two studies in monkeys published on Wednesday offer some of the first scientific evidence that surviving COVID-19 may result in immunity from reinfection, a positive sign that vaccines under development may succeed, U.S. researchers said on Wednesday.

Although scientists have assumed that antibodies produced in response to the new coronavirus virus are protective, there has been scant scientifically rigorous evidence to back that up.

In one of the new studies, researchers infected nine monkeys with COVID-19, the illness caused by the novel coronavirus. After they recovered, the team exposed them to the virus again and the animals did not get sick.

The findings suggest that they “do develop natural immunity that protects against re-exposure,” said Dr. Dan Barouch, a researcher at the Center for Virology and Vaccine Research at Harvard’s Beth Israel Deaconness Medical Center in Boston, whose studies were published in the journal Science.

“It’s very good news,” Barouch said.

Several research teams have released papers – many of them not reviewed by other scientists – suggesting that a vaccine against the virus would be effective in animals.

In the second study, Barouch and colleagues tested 25 monkeys with six prototype vaccines to see if antibodies produced in response were protective.

They then exposed these monkeys and 10 control animals to SARS-CoV-2, the official name of the novel coronavirus.

All of the control animals showed high degrees of virus in their noses and lungs, but in the vaccinated animals, “we saw a substantial degree of protection,” Barouch said. Eight of the vaccinated animals were completely protected.

These studies, which have been peer reviewed, do not prove that humans develop immunity or how long it might last, but they are reassuring.

“These data will be seen as a welcome scientific advance,” Barouch said.

(Reporting by Julie Steenhuysen; Editing by Bill Berkrot)