Tag Archives: Antibodies

Sleep apnea linked to COVID-19 outcomes

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 have yet to be certified by peer review.

Sleep apnea tied to severe COVID-19

The risk of severe illness from COVID-19 is higher in people with obstructive sleep apnea and other breathing problems that cause oxygen levels to drop during sleep, researchers say. They tracked 5,402 adults with these problems and found that roughly a third of them eventually tested posted for the coronavirus. While periodic episodes of not-breathing while asleep – leading to low oxygen levels, or hypoxia – did not increase people’s chances of being infected, sleep-related hypoxia did increase infected patients’ odds of needing to be hospitalized or dying from COVID-19, Drs. Cinthya Pena Orbea and Reena Mehra of the Cleveland Clinic and colleagues reported on Wednesday in JAMA Network Open. It is not clear if treatments that improve sleep apnea, such as CPAP machines that push air into patients’ airways during sleep, would also reduce the risk of severe COVID-19, said Pena Orbea and Mehra.

Body’s coronavirus memory may abort new infections

Healthcare workers who did not test positive for COVID-19, despite heavy exposure to infected patients, had T cells that attacked a part of the virus that lets it make copies of itself, according to a report published Wednesday in Nature. Researchers who studied the 58 healthcare workers found their T cells responded more strongly to a part of the virus, called the RTC, that is very similar on all human and animal coronaviruses, including all variants of SARS-CoV-2. They suspect the T cells recognized the RTC because they had “seen” it on other viruses during other infections. That makes the RTC a potentially good target for vaccines if more research confirms these findings, study leaders Mala Maini and Leo Swadling, both of University College London, said in a joint email to Reuters. These data were collected during the first wave of the pandemic, they added. “We don’t know if this sort of control happens for more infectious variants currently circulating.”

Vaccines induce neutralizing antibodies in breast milk

Infants might benefit from COVID-19 antibodies in breast milk regardless of whether mothers acquired the antibodies from being infected with SARS-CoV-2 or from vaccines, according to new findings reported on Wednesday in JAMA Pediatrics. Researchers studied antibodies in breast milk samples from 47 mothers who had been infected with the virus and 30 healthy mothers who had received the vaccines from Moderna or Pfizer/BioNTech. Antibodies from both groups were able to neutralize active SARS-CoV-2 virus, and while antibodies from infection were evident in milk for longer periods, antibody levels from vaccination “were much more uniform,” said study leader Bridget Young of the University of Rochester School of Medicine and Dentistry in New York. Thus, there is likely benefit to getting vaccinated even after a COVID-19 infection because breast milk would then contain a diverse variety of antibodies, she said. The researchers did not study the effect of the antibodies on the babies who consumed the milk.

(Reporting by Nancy Lapid; Editing by Tiffany Wu)

BioNTech says vaccine repeats beat devising new one for now

By Ludwig Burger

FRANKFURT (Reuters) -BioNTech said that repeat shots of its COVID-19 vaccine, of which more than a billion doses have now been supplied worldwide, was a better strategy than tailoring the product it developed with Pfizer to new variants.

The German biotech firm said that offering a third dose of its established two-shot vaccine remained the best response to concerns over waning immune protection in the face of the highly contagious Delta variant, as worse strains may emerge.

BioNTech said the more than one billion supply tally as per July 21 was up from 700 million-plus doses it announced in June.

This compares with AstraZeneca saying last month that it and manufacturing partner Serum Institute of India had supplied a billion doses of its vaccine globally.

Based on delivery contracts signed for more than 2.2 billion doses so far, BioNTech said in a statement detailing its second quarter earnings that it expects to accrue 15.9 billion euros ($18.7 billion) in revenue from the vaccine this year, up from a May forecast of 12.4 billion euros.

That includes sales, milestone payments and a share of gross profit in its partners’ territories, BioNTech added.

Pfizer late last month raised its forecast for its share of 2021 vaccine sales to $33.5 billion and said at the time it believes people will need a third dose of the shot.

Pfizer and BioNTech’s decision in early July to seek authorization for a third dose drew criticism from U.S. health regulators, who said there was not yet enough data to show booster shots are needed.

U.S. health agencies have since discussed additional doses for people with compromised immune systems, while Germany and France said they would roll out a third dose for the most vulnerable from September.

That jars with a call by the World Health Organization to use doses instead to jump-start vaccination campaigns in poorer nations which have so far been left behind.

BioNTech Chief Executive Ugur Sahin said that although work was ongoing to adjust the vaccine to variants it was not clear whether yet another version of the pathogen would supplant the now prevalent Delta variant.

“Making a decision at the moment might turn out to be wrong in three or six months if another variant is dominating,” Sahin said during an analyst call.

Chief Medical Officer Oezlem Tuereci said lab experiments had shown that a third shot of the established product generated neutralizing antibodies against a range of strains and that the antibody boost was above the one following a second dose.

Still, the company reiterated plans to start testing a vaccine adjusted to the Delta variant on humans this month, part of a “comprehensive strategy to address variants.”

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(Reporting by Ludwig BurgerEditing by Chizu Nomiyama and Alexander Smith)

Delayed 2nd Pfizer/BioNTech shot boosts antibodies in elderly; COVID-19 obesity risk higher for men

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.

Delaying second Pfizer/BioNTech dose boosts antibodies in elderly

Delaying the second dose of the Pfizer/BioNTech COVID-19 vaccine beyond the originally recommended three-week gap used by the companies in clinical trials appears to induce a stronger antibody response in the elderly, UK researchers found. Shortly after the vaccine became available, UK health officials advised that the second dose should be given 12 weeks after the first to allow more people to get protected by a first dose early on. In a new paper seen by Reuters and expected to appear on medRxiv on Friday ahead of peer review, researchers found that among 175 people ages 80 to 99, those who got their second dose at 12 weeks had antibody responses that were 3.5 times higher than those who got it after three weeks. Antibodies are only one part of the immune system, and vaccines also generate T cells that fight infections. The peak T cell responses were higher in the group with a three-week interval between doses, and the authors cautioned against drawing conclusions on how protected individuals were based on which dosing schedule they received.

Impact of obesity on COVID-19 risks may be greater in men

The known increased risk of severe COVID-19 and death linked to obesity may be even more pronounced for men than women, new data suggest. Researchers studied 3,530 hospitalized COVID-19 patients with an average age of 65, including 1,469 who were obese. In men, moderate obesity was associated with a significantly higher risk of developing severe disease, needing mechanical breathing assistance and dying from COVID-19. (The threshold for moderate obesity is a body mass index (BMI) of 35. In an 5-foot, five-inch tall (1.65 m) adult, that would correspond to a weight of 210 pounds (95 kg). In women, however, only a BMI of 40 or higher, indicating severe obesity, was linked with the increased risks. In a report published in European Journal of Clinical Microbiology & Infectious Diseases, the researchers note that while obesity is known to be linked with body-wide inflammation, patients’ levels of inflammatory proteins did not appear to explain the association between obesity and severe illness. For now, they conclude, “particular attention should be paid” to protecting patients with obesity from the coronavirus, “with priority to vaccination access, remote work, telemedicine, and other measures given the higher risk of adverse outcomes once they are diagnosed with COVID-19.”

COVID-19 testing rates low among symptomatic Americans

Sick Americans appear to be passing up opportunities to get tested for coronavirus and thus are likely unknowingly spreading the infection throughout their communities, new research shows. Among 37,000 adults across the United States who participated in a smartphone app survey between March and October 2020, nearly 2,700 reported at least one episode of fever and chills. But according to a report published in JAMA Network Open, only a small fraction reported receiving a COVID-19 test result within seven days of the onset of illness. At first, as tests became more accessible, the numbers improved. In early April 2020, less than 10% of survey participants reporting illness with fever received test results within a week. By late July, that proportion had increased to 24.1%. Throughout the summer and fall, as tests became easier to find, the number of sick participants who reported getting tested remained flat. By late October, only 26% reported receiving a test result within a week of febrile illness. “It’s shocking to me that when people have a fever they’re still not getting tested,” said coauthor Dr. Mark Pletcher of the University of California, San Francisco. “Tests are easy to come by. People might have coronavirus, might be spreading it to their friends and neighbors, and they’re not getting tested.”

(Reporting by Nancy Lapid, Alistair Smout and Ronnie Cohen; Editing by Bill Berkrot)

T cell response to virus variants remains potent; Asthma does not raise severe COVID-19 risk

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.

Immune system T cell responses to variants remain potent

While worrisome coronavirus variants identified in Brazil, South Africa, and California have mutations that might help them resist antibody treatments and vaccines, the immune system’s T cell responses to the variants are unaffected in recovered patients and in people who have received the Moderna Inc or Pfizer Inc/BioNTech SE vaccines, new data show. “We think this is really good news,” said Alessandro Sette of the La Jolla Institute for Immunology, whose team reported the findings on Monday on bioRxiv ahead of peer review. The T cells induced by vaccines can recognize pieces of the virus spike protein, while T cells induced by previous infection recognize multiple parts of the virus, including the spike and other proteins, Sette said. “These pieces are largely not changed/mutated in the variants,” he explained. “This means that the T cell responses recognize the ‘ancestral’ sequence and the variants equally well.” While circulating memory T cells would probably not prevent infection, they could reduce COVID-19 severity, he added. T cell responses are known to be linked with milder COVID-19, he noted, and may contribute to limiting COVID-19 severity induced by variants that partially or largely escape neutralizing antibodies.

Asthma does not increase COVID-19 risks

Asthma itself is not a risk factor for hospitalization or more severe COVID-19, and people whose asthma is triggered by allergies may actually be at lower risk, according to new research presented at the American Academy of Allergy, Asthma and Immunology virtual annual meeting. Researchers at Stanford University studied 5,596 patients who tested positive for COVID-19 from March to September 2020. Of these, 11% were hospitalized, including 100 patients with asthma. After accounting for patients’ other medical conditions that have been linked with more severe COVID-19 illness, including high blood pressure, heart disease, diabetes and obesity, “asthma was no longer a risk factor for hospitalization,” said Dr. Lauren Eggert. Among patients who were hospitalized, asthma was not significantly associated with disease severity, she said. Researchers also found that patients with allergic asthma were nearly half as likely as patients with other types of asthma to need hospitalization. A possible explanation, Eggert said, is that in allergic asthma, the immune system “downregulates,” or reduces the production, of the ACE2 proteins on cell surfaces that are a major port of entry for the coronavirus.

Antibodies to variants may offer cross-protection

Antibodies to a newer, more infectious coronavirus variant might prevent infection by earlier variants, laboratory studies suggest. In test tube experiments, researchers studied the neutralizing effects of antibodies obtained from people infected with COVID-19 in the first wave of the pandemic in South Africa, when the initial version of the virus was predominant, and in survivors from the second wave, when a more infectious, harder-to-treat new variant predominated. First-wave antibodies neutralized the first-wave virus but not second-wave virus. As expected, second-wave antibodies neutralized second-wave viruses. They also neutralized the first-wave virus, although not as potently, according to a paper posted on Saturday on medRxiv ahead of peer review. In a news conference on Wednesday, co-author Alex Sigal from the Africa Health Research Institute said the findings offer hope that vaccines based on the variant could protect against this and other variants circulating worldwide. Pfizer, AstraZeneca Plc, Johnson & Johnson and Moderna are already developing vaccines based on the variant identified in South Africa. Salim Abdool Karim, a top government adviser on COVID-19, predicted that by the end of 2021 most vaccine manufacturers will have adapted their shots, accordingly.

UK finds vaccines protect elderly

The Pfizer and AstraZeneca vaccines are more than 80% effective at preventing COVID-19 hospitalizations in people over age 80 after one dose, Public Health England said on Monday, citing a study released on medRxiv ahead of peer review. The UK study also found that in people over age 70, two doses of the Pfizer vaccine are approximately 85% to 90% effective at preventing symptomatic disease. Pfizer vaccine recipients in that age group who did acquire symptomatic infections had a 44% lower risk of hospitalization and a 51% lower risk of death compared to unvaccinated patients. Because the two-dose AstraZeneca vaccine had only recently been introduced, researchers only had data after one dose. The effect against symptomatic disease was approximately 60% to 75%, and there was also a protective effect against hospitalization, the researchers said. They noted that the AstraZeneca data was gathered while a more-infectious variant was predominant in the UK. Britain’s use of the AstraZeneca vaccine on elderly people contrasts with many European countries, which have cited a lack of clinical trial data for their decision not to use it on older people.

(Reporting by Nancy Lapid, Megan Brooks, Kate Kelland, and Alexander Winning; Editing by Bill Berkrot)

Some lingering COVID-19 issues seen in children; patients’ antibodies attack multiple virus targets

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.

Long lasting COVID-19 effects seen in children

“Long COVID” – a term that refers to effects of the virus that linger for weeks or months – may be a problem for children, too, a small study suggests. Doctors at a large Italian hospital tracked 129 children and teens with COVID-19 who were otherwise generally healthy. At an average of about five months after their diagnosis, only about 42% had completely recovered. Roughly one in three youngsters still had one or two symptoms and more than one in five had three or more, according to a report posted on Tuesday on medRxiv ahead of peer review. The most common persistent problems were insomnia (reported by 18.6%), respiratory symptoms including pain and chest tightness (14.7%), nasal congestion (12.4%), fatigue (10.8%), muscle pain (10.1%), joint pain (6.9%), and concentration difficulties (10.1%). Although these issues were more common in children who had been obviously sick, they also developed in infected youths with few or no symptoms initially. There is increasing evidence that restrictive measures aimed at curbing the pandemic are significantly impacting children’s mental health, the researchers acknowledge. Still, their findings suggest, the potential long-term effects COVID-19 can have on children should be considered when developing measures to reduce the impact of the pandemic on their overall health.

Patients’ antibodies target virus from many angles

Most antibody treatments and vaccines targeting the coronavirus focus on stimulating an immune response against the spike protein it uses to break into cells. Targeting other sites on the virus as well may be a better approach, researchers say. Their study of COVID-19 survivors whose immune systems had generated strong responses to the virus showed that more than half of those antibodies targeted components of the virus other than the spike protein. The most common non-spike targets of the antibodies were the closed capsule in which the virus stores its genetic instructions and specific segments of those instructions, such as stretches of its RNA code. This suggests that non-spike related antibodies may play a significant role in clearing the virus, the research team said in a paper posted on Thursday on bioRxiv ahead of peer review. In terms of natural immunity, it also suggests that when faced with new spike protein variants, the immune system will have other sites on the virus that it can still remember and attack. A spokesperson for the researchers said their company, Immunome Inc, is developing a cocktail of antibodies that target multiple sites on the virus.

COVID-19 may affect kidney filtering

COVID-19 impairs the kidneys’ ability to filter waste and toxic substances in some patients, a new report suggests. Kidney filters do not usually allow much protein into the urine. Researchers who studied 103 COVID-19 patients found that about 24% of them had high levels of the protein albumin in their urine, and 21% had high levels of the protein cystatin c in their urine. About 25% of the patients had a noninfectious piece of the coronavirus in their urine, but none of the samples contained infectious virus. That suggests the virus particles researchers did see were “a direct result of a filtration abnormality rather than a viral infection of the kidney,” according to a report posted on Sunday on medRxiv ahead of peer review. None of the patients had signs of kidney dysfunction, other than the filtration issues. “At this stage, we do not know whether or not these abnormalities are a sign of long-term consequences,” said coauthor Choukri Ben Mamoun of the Yale School of Medicine. “It is for this reason that we report these findings and emphasize the need for long-term examination of the consequences of this infection.”

(Reporting by Nancy Lapid; Editing by Bill Berkrot)

Racing the virus: Why tweaking the vaccines won’t be simple

By Julie Steenhuysen and Michael Erman

CHICAGO (Reuters) – After developing and rolling out COVID-19 vaccines at record speed, drugmakers are already facing variants of the rapidly-evolving coronavirus that may render them ineffective, a challenge that will require months of research and a massive financial investment, according to disease experts.

Executives from Moderna Inc and Pfizer Inc and partner BioNTech SE are considering new versions of their vaccines to respond to the most concerning variants identified so far. That is just one piece of the work needed to stay ahead of the virus, nearly a dozen experts told Reuters.

A global surveillance network to assess emerging variants must be built. Scientists need to establish what level of antibodies will be required to protect people from COVID-19 and determine when vaccines need to be altered. And regulators must convey what is needed to demonstrate updated vaccines are still safe and effective.

“At this point, there is no evidence that these variants have changed the equation in terms of protection from the vaccine,” said Dr. Michael Osterholm, an infectious disease expert at the University of Minnesota. “But we have to be prepared for that.”

Johnson & Johnson told Reuters the concerning variant first identified in South African has got its attention and will tweak its vaccine accordingly if needed. Pfizer said it could produce a new vaccine relatively quickly, but a top vaccine executive said manufacturing it presents additional challenges.

The urgency of this effort is clear.

Moderna on Monday said lab studies showed antibodies made in response to its vaccine were six times less effective at neutralizing a lab-created version of a South African variant than prior versions of the virus.

A study released on Wednesday ahead of peer review found the South African variant reduced neutralizing antibodies 8.6-fold for the Moderna vaccine and by 6.5-fold for the Pfizer/BioNTech shot, although a separate Pfizer-backed study released on Wednesday suggests its vaccine may be more hardy. Moderna said this week it is starting work on a potential booster shot.

COULD TAKE MONTHS

Just how far protection can drop before a COVID-19 vaccine needs to be altered is not yet known. With influenza, an eightfold drop in vaccine-induced antibody protection means time to update. That does not necessarily apply to this coronavirus.

“The problem is we don’t know what the cut point is for coronavirus,” said Dr. John Mascola, director of the Vaccine Research Center at the National Institute of Allergy and Infectious Diseases (NIAID), whose scientists helped develop Moderna’s vaccine.

Mascola said both studies testing the Moderna vaccine against the South African variant are roughly in the “same ballpark.” It could be that antibody protection is high enough from the vaccine that it will still be effective, he said.

NIAID scientists are analyzing data from Moderna’s late-stage trial to see what level of neutralizing antibodies is required for protection. They are comparing individuals who were vaccinated but got sick anyway to vaccinated people who remained healthy.

It could take two months to complete this work, Mascola said. They hope to produce a benchmark for the minimum level of vaccine-induced antibodies needed to protect against COVID-19.

A global surveillance network is also needed to identify troubling new variants as they emerge, similar to one used to track fast-mutating flu viruses. That could cost tens to hundreds of millions of dollars in the United States alone.

Richard Webby, a flu surveillance expert from St. Jude Children’s Research Hospital, said the United States could probably build a system to identify variants fairly quickly. Developing the capability to determine whether they evade current vaccines will take more time.

The United States is currently conducting genetic sequencing to look for changes in the virus in just 0.3% of positive coronavirus tests. That pales compared with 10% in the UK, which was first to discover a major mutation in the virus that increases transmission by at least 50%. Experts said countries should sequence at least 5% of positive cases to detect significant changes in the virus.

Companies are waiting for the U.S. Food and Drug Administration to relay what testing will be needed for altered vaccines, said Phil Dormitzer, one of Pfizer’s top viral vaccine scientists. With influenza vaccines, companies can make changes without new trials. “But that’s after doing it for 50 years,” he said.

Peter Marks, who oversees the FDA’s vaccine approval process, has said small trials testing updated vaccines in around 400 participants may be needed at first. Even that could add months to the process.

Norman Baylor, chief executive of Biologics Consulting and a former FDA vaccines official, said the agency will lay out the regulatory road. But public health agencies like the U.S. Centers for Disease Control and Prevention and the World Health Organization would decide when vaccines should be updated, as with flu.

Altering Pfizer’s vaccine would require “a very minor change,” Dormitzer said.

Like Moderna’s, it uses messenger RNA (mRNA) technology, which relies on synthetic genes that can be generated and manufactured in weeks.

He estimates the company could make a prototype version in a week or so, and take another two months to scale up and update their lab tests.

J&J, which is expected to release late-stage trial data on its vaccine within days, has laid the groundwork to address troubling virus changes, Chief Scientific Officer Paul Stoffels told Reuters. Its trial included sites in South Africa, which should give the company insight on that variant.

If a change is necessary, Stoffels said J&J likely would add a second strain into its existing vaccine.

“We are looking at this with a lot of attention,” he said.

(Reporting by Julie Steenhuysen in Chicago and Michael Erman in New York; Editing by Caroline Humer and Bill Berkrot)

South African virus variant may resist antibody drugs; Pfizer/BioNTech vaccine seems to work vs UK variant

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.

South African variant may resist current antibody treatments

The variant of the new coronavirus identified in South Africa can resist, or “escape,” antibodies that neutralize earlier versions of the virus, scientists have found. It “exhibits complete escape” from three classes of monoclonal antibodies manufactured for treating COVID-19 patients, and it shows “substantial or complete” resistance to neutralizing antibodies in blood donated by COVID-19 survivors, the scientists reported on Tuesday on bioRxiv ahead of peer review. Similarities between the South Africa variant and another variant identified in Brazil suggest the Brazilian variant will show similar resistance, they added. Liam Smeeth of the London School of Hygiene and Tropical Medicine, who was not involved in the study, noted that these were laboratory tests, and it would be unwise to extrapolate the findings to humans at this point. “The data do raise the possibility that the protection gained from past infection with COVID-19 may be lower for re-infection with the South African variant,” he said. “The data also suggest that the existing vaccines could be less effective against the South African variant.” He called for large studies among populations where the variant is common.

Pfizer/BioNTech shot likely protects against UK variant

The COVID-19 vaccine from Pfizer Inc and BioNTech SE is likely to protect against the more infectious variant of the virus discovered in Britain and now spreading around the world, according to laboratory tests. Researchers took blood samples from 16 people who had received the vaccine and exposed the blood to a synthetic virus, or pseudovirus, that was engineered to have 10 mutations found in the UK variant. The antibodies that had developed in response to the vaccine effectively neutralized the pseudovirus, according to a report posted on Tuesday on bioRxiv ahead of peer review. “This makes it very unlikely that the UK variant will escape from the protection provided by the vaccine,” said Jonathan Stoye, a virus scientist at Britain’s Francis Crick Institute who was not involved in the research. Similar experiments are needed with the more concerning variant first found in South Africa, he suggested. AstraZeneca Plc, Moderna Inc and CureVac NV are also testing whether their respective vaccines will protect against the fast-spreading variants.

Immune system will remember how to make COVID-19 antibodies

People who have recovered from COVID-19 can likely mount a fast and effective response to the virus if they encounter it again because their immune system’s “B cells” will remember how to make the antibodies needed to fight it, a new study shows. Researchers tracked 87 COVID-19 survivors for six months and found that while levels of antibodies to the virus may decline over time, the number of memory B cells remains unchanged. The antibodies produced by these cells are more potent than the patients’ original antibodies and may be more resistant to mutations in the spike protein the virus uses to break into cells, they said. For example, they found, the antibodies could recognize and neutralize at least one of the mutations in the South African variant of the virus that has caused concern among health experts. Even if antibody levels fall, B cells will remember how to make them when necessary, according to study leader Michel Nussenzweig of Rockefeller University, whose findings were reported on Monday in Nature. If this is true at six months, as in this study, it is safe to assume it is probably still true for longer periods, he added. People who have recovered from COVID-19 “may become infected but the immune system will be prepped to fight off the infection,” Nussenzweig said.

Mortality higher when ICUs are packed with COVID-19 patients

The more full an intensive care unit (ICU) is with COVID-19 patients, the higher the mortality rate among those patients, new data suggest. When researchers tracked outcomes of 8,515 COVID-19 patients admitted to 88 U.S. Veterans Affairs hospitals in 2020, they found that survival rates improved between March and August. Throughout the study period, however, the risk of death was nearly double when at least 75% of ICU beds were filled with COVID-19 patients, compared to when they accounted for no more than 25% of ICU beds. COVID-19 mortality “increases during periods of peak demand,” said Dr. Dawn Bravata of the Richard L Roudebush VA Medical Center in Indianapolis who co-led the study published on Tuesday in JAMA Network Open. “The more the public can do to avoid infections, the better,” she added. In addition, Bravata said, “facilities within a healthcare system or within a geographic region should collaborate to triage critically ill patients with COVID-19 to sites with greater ICU capacity to reduce strain on any one facility.”

(Reporting by Nancy Lapid, Linda Carroll, Kate Kelland and Ludwig Burger; Editing by Bill Berkrot)

COVID-19 infection gives some immunity, but virus can still be spread, study finds

By Kate Kelland

LONDON (Reuters) – People who have had COVID-19 are highly likely to have immunity to it for at least five months, but there is evidence that those with antibodies may still be able to carry and spread the virus, a study of British healthcare workers has found.

Preliminary findings by scientists at Public Health England (PHE) showed that reinfections in people who have COVID-19 antibodies from a past infection are rare – with only 44 cases found among 6,614 previously infected people in the study.

But experts cautioned that the findings mean people who contracted the disease in the first wave of the pandemic in the early months of 2020 may now be vulnerable to catching it again.

They also warned that people with so-called natural immunity – acquired through having had the infection – may still be able carry the SARS-CoV-2 coronavirus in their nose and throat and could unwittingly pass it on.

“We now know that most of those who have had the virus, and developed antibodies, are protected from reinfection, but this is not total and we do not yet know how long protection lasts,” said Susan Hopkins, senior medical adviser at PHE and co-leader of the study, whose findings were published on Thursday.

“This means even if you believe you already had the disease and are protected, you can be reassured it is highly unlikely you will develop severe infections. But there is still a risk you could acquire an infection and transmit (it) to others.”

MAJOR IMPLICATIONS

Experts not directly involved in the research, which is known as the SIREN study, urged people to note its key findings.

“These data reinforce the message that, for the time being, everyone is a potential source of infection for others and should behave accordingly,” said Eleanor Riley, a professor of immunology and infectious disease at Edinburgh University.

Simon Clarke, an associate professor in cellular microbiology at Reading University, said the study “has major implications for how we can get out of the current crisis”.

“This means that the vast majority of the population will either need to have natural immunity or have been immunized for us to fully lift restrictions on our lives, unless we are prepared to see many more people being infected and dying from COVID-19,” he said.

PHE said in a statement that the study had not been able to explore antibody or other immune responses to the COVID-19 vaccines being rolled out in Britain. Vaccine effects would be studied as part of SIREN later this year, it said.

The SIREN study involves tens of thousands of healthcare workers in Britain who have been tested regularly since June for new COVID-19 infections as well as for the presence of antibodies.

Between June 18 and Nov. 24, scientists found 44 potential reinfections – two “probable” and 42 “possible” – among 6,614 participants who had tested positive for antibodies. This represents an 83% rate of protection from reinfection, they said.

The researchers said they would continue to follow the participants to see if this natural immunity might last longer than five months in some. But they said early evidence from the next stage of the study suggested some people with immunity could still carry high levels of virus.

(Reporting by Kate Kelland; Editing by Mark Heinrich, Robert Birsel)

Immune system can cause broad damage in COVID-19; dogs can detect coronavirus in people

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.

Immune system can self-attack broadly in COVID-19

Antibodies are supposed to attack invading germs, but severely ill COVID-19 patients have so-called autoantibodies that mistakenly attack not just their own tissues and organs but even virus-fighting proteins produced by the immune system, new research shows. Scientists studied 194 COVID-19 patients, including 55 with severe disease, plus a control group of 30 people without the virus. In the sickest patients, they found a high frequency of autoantibodies created by the immune system causing injury to the central nervous system, blood vessels, and connective tissues like cartilage, ligaments and tendons. They also found a high prevalence of autoantibodies that interfere with substances involved in the functioning of the immune system itself, including cytokines and other “immunomodulatory” proteins. “The surprising extent of autoantibody reactivities” in these patients indicates that these mistakenly targeted antibodies are “an intrinsic aspect” of COVID-19. The report was posted on medRxiv on Saturday ahead of peer review.

Dogs can sniff out COVID-19

Trained dogs can identify people with COVID-19, even those with no symptoms, according to researchers. In the preliminary study published on Thursday in PLoS One, dogs who sniffed swab samples of armpit sweat could tell which samples came from COVID-19 patients and which were from people who tested negative for the new coronavirus. That study was conducted in March. More recently, the researchers have validated the findings in additional trials, said study leader Dominique Grandjean of Alfort Veterinary School in France. Dogs can identify infected individuals with 85% to 100% accuracy and rule out infection with 92% to 99% accuracy, Grandjean said. “It takes one tenth of a second for a trained dog to say ‘yes’ or ‘no’,” he said. Training requires 3 to 8 weeks depending on whether the dog is already trained for odor detection. COVID-19-detecting dogs have already been deployed in airports in the United Arab Emirates, Grandjean said. On Wednesday, the UAE and the International K9 Working Group Against COVID-19 will host a virtual workshop on the use of these trained dogs, with 25 countries expected to participate, according to the organizers.

COVID-19 not linked with Guillain-Barré syndrome

COVID-19 is not associated with the potentially paralyzing disorder Guillain-Barré syndrome (GBS), a large UK study shows. In GBS, the immune system mistakenly attacks nerves in the feet, hands and limbs. Smaller studies have suggested a link between COVID-19 and GBS. But when researchers compared the number of GBS cases recorded in the UK’s National Health Service database in 2016 to 2019 to the number recorded in the first half of 2020, they found the annual incidence was 40% to 50% lower during the pandemic. “No causal link of COVID-19 to GBS can be made,” Stephen Keddie of University College London said in a statement. His team reported on Monday in the journal Brain that they also looked for – but could not find – any genetic or protein structure in the new coronavirus that might trigger an immune response causing GBS, which is good news for vaccine development. “Most COVID-19 vaccinations are based on the (coronavirus’) spike protein, which drives a complex immune response creating antibodies to fight infection,” Keddie said. Since researchers found nothing in the virus that is known to drive GBS, “concerns that COVID vaccination might cause GBS in any significant numbers are therefore almost certainly unfounded,” he said.

Antibiotic azithromycin fails to help in severe COVID-19

The antibiotic azithromycin failed to help seriously ill adults infected with the new coronavirus, according to results from a clinical trial. Based on the result, the only COVID-19 patients who should get the antibiotic are those who also have bacterial infections, the study leaders said. The trial, conducted at 176 hospitals across the UK, involved more than 9,000 patients and tested multiple drugs to see if any would be more effective than standard hospital care in treating COVID-19. According to preliminary data published on Monday on medRxiv ahead of peer review, patients who were randomly assigned to receive azithromycin did no better than patients who got standard care in terms of deaths, duration of hospitalization, or need for mechanical ventilation. “More than 75% of hospitalized COVID-19 patients are prescribed antibiotics,” the researchers point out. “Although we detected no harm to individual patients treated with azithromycin, there is a risk of harm at a societal level from widespread use of antimicrobial agents,” researchers said. The widespread use of antibiotics in COVID-19 patients “in general must be questioned,” they concluded.

(Reporting by Nancy Lapid; Editing by Bill Berkrot)

COVID-19 antibodies last at least three months; so do symptoms for many

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 antibodies last at least three months

People infected with COVID-19 develop antibodies targeting the new coronavirus that last for at least three months, according to two reports published on Thursday in Science Immunology. The two studies, together involving nearly 750 patients, both point to immunoglobulin G (IgG) antibodies, which start showing up well after an infection begins, as the longest-lasting. Researchers found IgG antibodies with two targets – a spike protein on the virus that helps it infect cells, and a part of the spike called the receptor binding domain (RBD) – lasted more than 100 days. While the protective effect of COVID-19 antibodies is not completely clear, Jen Gommerman of the University of Toronto, coauthor of the study, said her team also found levels of so-called neutralizing antibodies, which inactivate the virus, “appeared to be very stable.” The other study, from Harvard Medical School, reported similar findings. This means that a properly designed vaccine “should elicit a durable antibody response that has the potential to neutralize the virus,” Gommerman said. Her group also found that antibodies in saliva correlated with antibodies in blood, but at this point the saliva tests are not sensitive enough to replace blood tests.

COVID-19 symptoms linger for months for many

Three months after becoming ill, many COVID-19 patients still have symptoms, two studies confirm, and the more severe the initial infections, the higher the odds of persistent problems. In Spain, doctors checked back with 108 patients, including 44 who had been severely ill. At 12 weeks after diagnosis, 76% still reported after-effects, with 40% reporting three or more coronavirus-related health issues, doctors said in a paper posted on Thursday on medRxiv ahead of peer review. The most common complaints were shortness of breath, physical weakness, cough, chest pain, palpitations, and psychological and cognitive disorders. In a similar study of 233 U.S. COVID-19 patients – eight of whom had been severely ill – one in four still had symptoms 90 days after first feeling ill. Rates were higher for patients who had been sicker: 59.4% at 30 days and 40.6% at 90 days. “But even for very mild and initially asymptomatic cases, 14.3% have complications persist for 30 days or longer,” the authors reported on Sunday on medRxiv. In the U.S. study, the most common persistent symptoms were impaired smell and taste, difficulty concentrating, shortness of breath, memory loss, confusion, headache, heart palpitations, chest pain, pain with deep breaths, dizziness, and rapid heartbeat.

Remdesivir cut COVID-19 recovery time by 5 days

Final data from a large study of Gilead Sciences Inc’s antiviral drug remdesivir showed the treatment cut COVID-19 recovery time by five days among hospitalized patients, one day faster than preliminary data had indicated, researchers reported on Thursday in The New England Journal of Medicine. The 1,062-patient study compared up to up to 10 days of therapy with remdesivir – now sold in some markets as Veklury – to a placebo. The average recovery time was 10 days among those who got the Gilead drug versus 15 days in the placebo group. Among patients requiring oxygen at the start, those taking remdesivir continued to need oxygen for an average of 13 days, compared to 21 days for patients who got a placebo. In a separate analysis looking just at patients who received oxygen, the drug appeared to reduce the risk of death over the next month by 70%. “We now have data suggesting that giving remdesivir to patients on oxygen may significantly reduce their chances of death compared to other subgroups,” Dr. Andre Kalil, an infectious disease expert at the University of Nebraska Medical Center and the study’s lead investigator, said in a news release.

Coronavirus rarely travels from mother to newborn

Transmission of the new coronavirus from mothers to newborns is rare, doctors from New York-Presbyterian/Columbia University Irving Medical Center reported on Monday in JAMA Pediatrics. They studied 101 babies born to 100 mothers with COVID-19, including 10 whose mothers had been severely ill. Almost all of the babies tested negative for the virus, while tests in two newborns had indeterminate results. If these two indeterminate results are considered positive, the overall incidence of transmission was 2.0%. Even with a 2% transmission rate, “none of our babies exhibited clinical symptoms of COVID-19, either during their newborn nursery stay or during … the first few weeks of life,” coauthor Dr. Dani Dumitriu told Reuters Health by email. Roughly 90% of the newborns were breastfed at least partially. “As the country heads into what looks like a second wave of the COVID-19 pandemic, it is important to know that separation of affected mothers from their newborns may not be warranted, and direct breastfeeding appears to be safe,” study coauthor Dr. Melissa Stockwell said.

(Reporting by Nancy Lapid, Julie Steenhuysen and Will Boggs; Editing by Bill Berkrot)