Virus World
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Virus World
Virus World provides a daily blog of the latest news in the Virology field and the COVID-19 pandemic. News on new antiviral drugs, vaccines, diagnostic tests, viral outbreaks, novel viruses and milestone discoveries are curated by expert virologists. Highlighted news include trending and most cited scientific articles in these fields with links to the original publications. Stay up-to-date with the most exciting discoveries in the virus world and the last therapies for COVID-19 without spending hours browsing news and scientific publications. Additional comments by experts on the topics are available in Linkedin (https://www.linkedin.com/in/juanlama/detail/recent-activity/)
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Opinion | H5N1 Bird Flu is Causing Alarm. Here’s Why We Must Act. - The New York Times

Opinion | H5N1 Bird Flu is Causing Alarm. Here’s Why We Must Act. - The New York Times | Virus World | Scoop.it

Bird flu has spread widely among animals. Unless we act now, it soon could do the same among humans. As the world is just beginning to recover from the devastation of Covid-19, it is facing the possibility of a pandemic of a far more deadly pathogen. Bird flu — known more formally as avian influenza — has long hovered on the horizons of scientists’ fears. This pathogen, especially the H5N1 strain, hasn’t often infected humans, but when it has, 56 percent of those known to have contracted it have died. Its inability to spread easily, if at all, from one person to another has kept it from causing a pandemic. But things are changing. The virus, which has long caused outbreaks among poultry, is infecting more and more migratory birds, allowing it to spread more widely, even to various mammals, raising the risk that a new variant could spread to and among people. Alarmingly, it was recently reported that a mutant H5N1 strain was not only infecting minks at a fur farm in Spain but also most likely spreading among them, unprecedented among mammals. Even worse, the mink’s upper respiratory tract is exceptionally well suited to act as a conduit to humans, Thomas Peacock, a virologist who has studied avian influenza, told me. The world needs to act now, before H5N1 has any chance of becoming a devastating pandemic. We have many of the tools that are needed, including vaccines. What’s missing is a sense of urgency and immediate action. The best defense against a new deadly pathogen is aggressively suppressing early outbreaks, which first requires detecting them quickly. The United States, the World Health Organization and global health officials already have influenza surveillance networks, but many avian influenza experts told me they don’t think the networks are functioning well enough given the threat level. Such surveillance would need to prioritize people in the poultry industry but also expand beyond that. Thijs Kuiken, an expert in avian influenza at Erasmus University Medical Center in Rotterdam, the Netherlands, says farms for pigs — another species susceptible to influenza — should also be surveilled for bird flu. People interacting with wild birds and animals, as well as susceptible species of pets like ferrets, are also at higher risk. It’s not enough to detect, though: Suppression would require a major effort and global coordination. Unfortunately, mink farms must be shut down — even if it means killing the minks. They are typically killed anyway for their fur at about 6 months of age. It’s hard to imagine a better way to incubate and spread a deadly virus than letting it evolve among tens of thousands of animals with an upper respiratory tract similar to ours crowded together. When the coronavirus infected Danish mink farms in 2020 and the minks generated new variants that then infected humans, the efforts to save the industry were futile because the outbreaks were uncontrollable.

 

If different strains of flu have infected the same person simultaneously, the strains can swap gene segments and give rise to new, more transmissible ones. If a mink farmworker with the flu also gets infected by H5N1, that may be all it takes to ignite a pandemic. To avoid this, quick testing should be widely available and easy to obtain globally, especially for poultry workers and people handling wild birds or other wildlife. And current testing capabilities should be quickly expanded. There are 91 public health labs in the United States that can test for H5 influenza. Positive results are sent to the Centers for Disease Control and Prevention, where further analyses can detect H5N1 within about 48 hours. But plans should be in place to increase the amount of tests and testing facilities in case demand ramps up. Perhaps the best news is that we have several H5N1 vaccines already approved by the Food and Drug Administration whose safety and immune response have been studied. The U.S. government has a small H5N1 vaccine stockpile, but it would be nowhere near enough if a serious outbreak occurred. The current plan is to mass-produce them if and when such an outbreak occurs, based on the particular variant involved. There are several problems, though, with this approach even under the best-case scenarios. Producing hundreds of millions of doses of a new vaccine could take six months or more. Worryingly, all but one of the approved vaccines are produced by incubating each dose in an egg. The U.S. government keeps hundreds of thousands of chickens in secret farms with bodyguards. (It’s true!) But the bodyguards are presumably there to fend off terror attacks, not a virus. Relying on chickens to produce vaccines against a virus that has a 90 percent to 100 percent fatality rate among poultry has the makings of the most unfunny which-came-first, the-chicken-or-the-egg riddle. The only company with an F.D.A.-approved non-egg-based H5N1 vaccine expects to be able to produce 150 million doses within six months of the declaration of a pandemic. But there are seven billion people in the world. The mRNA-based platforms used to make two of the Covid vaccines also don’t depend on eggs. Scott Hensley, an influenza expert at the University of Pennsylvania, told me that those vaccines can be mass-produced faster, in as little as three months. There are currently no approved mRNA vaccines for influenza, but efforts to make one should be expedited. If the W.H.O. is to take the lead in expanding global vaccine manufacturing, it needs the support of wealthy countries and the cooperation of large pharmaceutical companies that have the patents and know-how. A big challenge to stockpiling flu vaccines is that they can lose potency over time and need updating as new variants arise. The U.S. government is skeptical about creating a large stockpile, fearing that stored vaccines may not be effective against whatever strain became pandemic, and worries that stockpiles will expire anyway. Officials also have faith that they can get new flu vaccines mass-produced rapidly.

 

Many influenza experts told me that older vaccines could still provide some protection against severe outcomes or death. Peter Palese, a professor of microbiology at the Icahn School of Medicine at Mount Sinai, who established the first genetic maps for influenza A, B and C viruses, told me that such stockpiles would be especially useful for essential workers. In 2017, the C.D.C. found that the H5N1 vaccine made in 2004 and 2005 helped protect ferrets against an H5N2 virus in 2014. Investigations in 2006 showed that 80 percent of the U.S. stockpile of earlier H5N1vaccines were still potent a full year after their expected one-year shelf life had passed. In 2019, another study found that H5N1 vaccines produced as early as 2004 were still potent a full 12 years later. We could also allow voluntary vaccination, especially for high-risk groups like poultry workers and health care workers, who would be treating patients should outbreaks occur. Voluntary vaccination could also produce larger-scale data on the safety and dosing specifics of vaccines. Vaccinating poultry workers has the additional big benefit of helping suppress outbreaks in the first place. Several influenza experts I spoke to bemoaned the lack of more widespread vaccination for chickens and turkeys. Had all poultry been vaccinated earlier, perhaps H5N1 would have never spread so widely to wild birds. It’s late, but mass vaccination of poultry and pigs should begin quickly. Even getting more people vaccinated — especially poultry and pig farmworkers — against the regular influenza can help. With less regular flu in the world, there would be fewer hosts for an H5N1 virus to co-infect, a process that can lead to strains of H5N1 that can spread more easily.

 

We already have antivirals for influenza, which work regardless of strain, but they need to be administered early, which requires widespread early testing, easy access, and sufficient and equitable stockpiles globally. Scientists are working toward a universal flu vaccine, potentially covering all variants as well as future pandemic ones — a moonshot, perhaps, but worth the investment.

The pace of developments has been disquieting. Until 2020, when the new H5N1 strain began to spread extensively among wild birds, most big outbreaks occurred among poultry. But now, with wild birds acting as conduits, it’s not just the biggest outbreak ever among poultry, causing the death of at least 150 million animals so far, but it is also steadily expanding its reach, including to mammal species like dolphins and bears. In 2006, when scientists discovered that H5N1 had not spread easily among humans because it settles deep in their lungs, Kuiken of Erasmus University Medical Center warned that if the virus evolved to bind to receptors in the upper respiratory tract — from which it could become more easily airborne — the risk of a pandemic among humans would rise substantially. The mink outbreak in Spain is a signal that we might be moving along exactly that path.

It’s hard to imagine clearer and more alarming warning signs of a potentially horrific pandemic. The public, of course, doesn’t want to hear about another virus, and Congress isn’t even willing to keep funding efforts against the current one. We could get lucky — we’ve had bird flu outbreaks before without human spread. But it seems foolish to count on that. A pandemic strain may have a much lower fatality rate than the 56 percent of known human cases so far, but it still could be much more deadly than the coronavirus, which is estimated to have killed 1 percent to 2 percent of those infected before vaccines or treatments were available. Deadly influenza pandemics occur regularly in human history, and they don’t wait until people recover from an earlier outbreak, no matter how weary we may all feel. This time, we have not just the warning, but also many of the tools we need to fend a pandemic off. We should not wait until it’s too late.

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The Most Bitter Part of the Coronavirus Pandemic

The Most Bitter Part of the Coronavirus Pandemic | Virus World | Scoop.it

Medical historians describe how the coronavirus pandemic isn't a fluke event. Such a disease outbreak has long been expected, and will happen again. For the crime of spitting in public, New York City officials arrested and fined 144 men on Oct. 4, 1918, during the second — and deadliest — wave of the flu pandemic. Cases had suddenly spiked, and the city’s Department of Health became desperate to curb the spreading disease. With no hope for a vaccine nor a cure, the city posted bulletins imploring people to sneeze into handkerchiefs, avoid crowds, stop spitting, and wash their hands. During the heat of the pandemic, some New Yorkers donned masks. Yet now, over 100 years later, we’re stuck combating the latest human scourge, the newly emerged coronavirus, in mostly the same ways. (Though perhaps spitting is less of a problem.)

 

Our eventual savior — similar to combating afflictions like polio and smallpox — will be a vaccine, creating widespread immunity against the virus. Yet developing a new vaccine for this new human contagion will likely mean waiting a long time, at the optimistic best perhaps some time in winter or in 2021, when one of ten promising vaccine candidates might safely work. And any miracle cure, for those severely sickened, is unlikely to come much sooner (there’s still no evidence the touted malaria drug hydroxychloroquine curtails deaths). This may all come as sour news. But it’s not the most bitter news of all for our vulnerable species. The most troubling reality of a sustained pandemic that has killed over 112,000 Americans (as of June 10), shuttered cities, and emptied stadiums, is this isn’t some fluke.

 

It has long been expected. It’s totally predictable. And an outbreak will happen again. “The history of humanity is punctuated by pandemics,” said Dr. Richard Gunderman, an M.D. and medical historian at Indiana University. “This is just another chapter in that big volume.”....

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Prompt NAI treatment reduced hospital stays by 19% during last flu pandemic

Prompt NAI treatment reduced hospital stays by 19% during last flu pandemic | Virus World | Scoop.it

Neuraminidase inhibitor treatment initiated upon hospitalization decreased patients’ length of stay by 19% overall during the 2009-2010 influenza pandemic, according to findings from a meta-analysis. “The most pragmatic and important question is whether [neuraminidase inhibitor (NAI)] treatment, started on admission, irrespective of delay since symptom onset, reduces the [length of stay] in hospitalized patients with influenza,” Sudhir Venkatesan, PhD, MPH, research assistant in the University of Nottingham’s division of epidemiology and public health, and colleagues wrote. “Clinically, this is important because there can be significant uncertainty in ascertaining symptom onset, even by the attending physician.”

 

The meta-analysis included data on 18,309 patients infected with the pandemic influenza A(H1N1) virus from 70 clinical centers in 36 countries, and excluded patients with a length of stay less than 1 day and individuals who died while hospitalized. The study results showed a 19% overall reduction in length of stay among patients who were promptly administered NAI treatment upon hospitalization compared with those who received it later or not at all (incidence rate ratio, 0.81; 95% CI, 0.78-0.85), with a median decrease of 1.19 days. 

 

NAI treatment initiated less than 2 days after the onset of symptoms as well as NAI treatment administered at any time showed mixed patterns of association with a patient’s length of stay, the researchers reported. They observed an 8% decrease in length of stay in patients who were treated on the day of admission and not admitted to the ICU, and a 28% increase in promptly treated patients with chest radiography-confirmed influenza-related pneumonia.

 

The study was published July 17 in the Journal of Infectious Diseases:

https://doi.org/10.1093/infdis/jiz152

Juan Lama's insight:

The study evaluated patients treated with several NAI, including oselttamivir, peramivir or zanamivir. Unfortunately, the results were not reproduced in children (only adults), and the authors provide some explanations for this.

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Promising Universal Flu Vaccine Could Protect Against 20 Strains

Promising Universal Flu Vaccine Could Protect Against 20 Strains | Virus World | Scoop.it

An mRNA vaccine has been found to induce antibody responses against all 20 known subtypes of influenza A and B in mice and ferrets. An experimental vaccine has generated antibody responses against all 20 known strains of influenza A and B in animal tests, raising hopes for developing a universal flu vaccine. Influenza viruses are constantly evolving, making them a moving target for vaccine developers. The annual flu vaccines available now are tailored to give immunity against specific strains predicted to circulate each year. However, researchers sometimes get the prediction wrong, meaning the vaccine is less effective than it could be in those years. Some researchers think annual flu jabs could be replaced by a universal flu vaccine that is effective against all flu strains. Researchers have tried to achieve this by making vaccines containing protein fragments that are common to several influenza strains, but no universal vaccine has yet gained approval for wider use. Now, Scott Hensley at the University of Pennsylvania and his colleagues have created a vaccine based on mRNA molecules – the same approach that was pioneered by the Pfizer/BioNTech and Moderna covid-19 vaccines. mRNA contains genetic codes for making proteins, just like DNA. The vaccine contains mRNA molecules encoding fragments of proteins found in all 20 known strains of influenza A and B – the viruses that cause seasonal outbreaks each year. The strains have different versions of two proteins on their surface, haemagglutinin (H) and neuraminidase (N), which are targeted by immune responses. But even within one strain, such as H1N1, there can be slight variations in these proteins, so the version in the universal vaccine will not exactly match every possible variant.

 

In tests in mice, the team found that the animals generated antibodies specific to all 20 strains of the flu virus, and these antibodies remained at a stable level for up to four months. In another test, the team gave mice the universal flu vaccine or a dummy vaccine containing code for a non-flu protein. A month later, they infected them with either one of two variants of the H1N1 flu virus, one with an H1 protein that was very similar to the version of the protein in the vaccine, and one with a more distinct version. All the mice given the flu vaccine survived exposure to the virus with the more similar protein and 80 per cent survived being infected with the more distinct variant. All of the mice given the dummy vaccine died around a week after infection with either variant. Another group of mice were given an mRNA vaccine targeted only to the precise flu strain they were exposed to, and all of this group survived over the same time period. This suggests the universal flu vaccine would offer less protection against new variants of the 20 flu strains than an annual vaccine matched to new forms of the virus, says Albert Osterhaus at the University of Veterinary Medicine Hannover in Germany, who wasn’t involved in the study. The researchers also tested the universal vaccine in ferrets with similar results.

 

“The mouse and ferret models for influenza are as good as animal models get. The animal data are promising and thus a good indication of what will happen in humans,” says Peter Palese at the Icahn School of Medicine at Mount Sinai in New York. A key benefit of mRNA vaccines is that they can easily be scaled up compared with other approaches which rely on growing influenza viruses in chicken eggs or in the lab, says Palese. “For generating a basic immunity against epidemic or pandemic influenza virus strains in the future, this strategy could offer an option if longevity [of immunity] in humans is confirmed,” says Osterhaus. “Definitely these animal data are promising and merit further exploration in clinical studies. Given previous studies with candidate universal flu vaccines in human trials, it is hard to predict what the clinical data will bring,” says Osterhaus. “This 20-HA mRNA vaccine was tested in ferret animals, which is highly significant and may hold promise for protecting against future emerging flu strains against severe disease in humans,” says Sang-Moo Kang at Georgia State University.

 

Study cited published in Science (Nov. 24):

https://doi.org/10.1126/science.abm0271 

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How Does the New Coronavirus Compare with the Flu?

How Does the New Coronavirus Compare with the Flu? | Virus World | Scoop.it

The new coronavirus outbreak has made headlines in recent weeks, but there’s another viral epidemic hitting countries around the world: flu season. But how do these viruses compare, and which one is really more worrisome?  So far, the new coronavirus, dubbed 2019-nCoV, has led to more than 20,000 illnesses and 427 deaths in China, as well as more than 200 illnesses and two deaths outside of mainland China. But that’s nothing compared with the flu, also called influenza. In the U.S. alone, the flu has already caused an estimated 19 million illnesses, 180,000 hospitalizations and 10,000 deaths this season, according to the Centers for Disease Control and Prevention (CDC). That said, scientists have studied seasonal flu for decades. So, despite the danger of it, we know a lot about flu viruses and what to expect each season. In contrast, very little is known about 2019-nCoV because it’s so new. This means 2019-nCoV is something of a wild card in terms of how far it will spread and how many deaths it will cause. 

 

“Despite the morbidity and mortality with influenza, there’s a certainty … of seasonal flu," Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in a White House press conference on Jan. 31. “I can tell you all, guaranteed, that as we get into March and April, the flu cases are going to go down. You could predict pretty accurately what the range of the mortality is and the hospitalizations [will be],” Fauci said. “The issue now with [2019-nCoV] is that there’s a lot of unknowns.”  Scientists are racing to find out more about 2019-nCoV, and our understanding of the virus and the threat it poses may change as new information becomes available. Based on what we know so far, here’s how it compares with the flu....

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