Tag: avian flu

Categories : VaccinesTags :

Needle-free Influenza Vaccines with Broad Protection

On By ModernMedia
Photo by CDC on Unsplash

A research team led by the University of Hong Kong have achieved an award-winning breakthrough in developing broadly protective, live-attenuated influenza vaccines (LAIV). These innovative LAIV platforms offer the potential to develop universal influenza vaccines that induce a more robust immune response against various virus subtypes, including both human and avian strains. Since they induce mucosal immune responses, they can also be administered nasally.

Current seasonal influenza vaccines protect primarily against three selected strains and require annual updates. Their efficacy can significantly decline if the circulating viruses do not match the strains chosen each year for each hemisphere. Moreover, these vaccines fail to guard against human infections caused by animal influenza viruses, such as avian strains, which pose a potential global pandemic threat. The World Health Organization (WHO) has underscored the urgent need for a new generation of universal influenza vaccines.

The research team developed two innovative approaches to create next-generation LAIVs. The first strategy involved engineering a human influenza virus with then gene for α-Gal, which is already targeted by human antibodies. Vaccine-infected cells then express α-Gal on their surfaces and boost vaccine-induced immune responses, including antibody-mediated cytotoxicity, opsonisation and phagocytosis.

The research data showed that the vaccine is attenuated in mouse models. Vaccinated mice showed strong innate and adaptive immune responses, including antibody and T-cell responses. These immune responses conferred broad protection against various influenza A virus subtypes, including human H1N1 and H3N2, and avian H5N1 strains.

The second approach to developing next-generation LAIVs involved introducing hundreds of silent mutations to a human influenza virus, shifting its codon usage from that of a human influenza virus to that of an avian influenza virus-like pattern. This shift resulted in the attenuation of the virus in mammalian cells, making it safe for use as an LAIV.

Additionally, the mutant virus replicated perfectly in chicken eggs, which is crucial for current effective vaccine manufacturing processes. With this approach, the viral protein expression of the LAIV remained identical to the original wild-type virus, providing a robust immune response against the viruses. The research team successfully generated several attenuated viruses with different human influenza virus backbones, including H1N1 and H3N2.

The development of these two award-winning LAIVs represents a significant advancement in the quest for broadly protective and efficient influenza vaccines. This new generation of LAIVs can both protect humans from seasonal influenza viruses and address the threat posed by emerging viruses, like avian influenza viruses.

“The advantages of LAIVs lie in their intranasal administration, which has been shown to induce mucosal immune responses along the respiratory tract, providing additional protection against infection,” highlighted Professor Leo Poon Lit-man, Chair Professor of Public Health Virology and Head of the Division of Public Health Laboratory Sciences, School of Public Health, HKUMed. “This needle-free delivery method alleviates the fear of vaccination, particularly in young children, so it will help mitigate vaccine hesitancy.”

Source: The University of Hong Kong

Categories : Regenerative MedicineTags :

Bird flu is Mutating, but Antivirals Still Work

On By ModernMedia
Professor Luis Martinez-Sobrido, Ph.D., (left) and Staff Scientist Ahmed Mostafa Elsayed, PhD, (right) review test results for the presence of bird flu while wearing protective equipment required for biosafety level-3 laboratories.

One of the earliest strains of bird flu isolated from a human in Texas shows a unique constellation of mutations that enable it to more easily replicate in human cells and cause more severe disease in mice compared to a strain found in dairy cattle, researchers from Texas Biomedical Research Institute (Texas Biomed) report in Emerging Microbes & Infections.

The finding highlights a key concern about the H5N1 strains of bird flu currently circulating in the U.S.: the speed at which the virus can mutate when introduced to a new host.

Naturally found in wild birds and lethal in chickens, H5N1 has spread to a wide variety of mammals and began infecting dairy cows for the first time in spring 2024. As of early 2025, the outbreak had spread through herds across multiple states in the U.S. and infected dozens of people, mostly farm workers. So far, most people infected experience mild illness and eye inflammation and the virus is not spreading between people. The first H5N1 death in the U.S. was reported in January 2025 following exposure to infected chickens.

“The clock is ticking for the virus to evolve to more easily infect and potentially transmit from human to human, which would be a concern,” said Texas Biomed Professor Luis Martinez-Sobrido, PhD, whose lab specialises in influenza viruses and has been studying H5N1 since the outbreak began last year. The team has developed specialised tools and animal models to test prophylactic vaccines and therapeutic antivirals.

Human vs bovine

In the recent study, they compared H5N1 strains isolated from a human patient and from dairy cattle in Texas.

“There are nine mutations in the human strain that were not present in the bovine strain, which suggests they occurred after human infection,” Dr Martinez-Sobrido said.

In mouse studies, they found that compared to the bovine strain, the human strain replicated more efficiently, caused more severe disease and was found in much higher quantities in brain tissue. They also tested several FDA-approved antiviral medications to see if they were effective against both virus strains in cells.

“Fortunately, the mutations did not affect the susceptibility to FDA-approved antivirals,” said Staff Scientist Ahmed Mostafa Elsayed, PhD, first author of the study.

Antivirals will be a key line of defence should a pandemic occur before vaccines are widely available, Dr Martinez-Sobrido said. This is especially true since humans have no preexisting immunity against H5N1 and seasonal flu vaccines appear to offer very limited protection, according to a separate study conducted in collaboration with Aitor Nogales, PhD, at the Center for Animal Health Research in Spain.

Dr Elsayed shows the host species of the four types of influenza viruses: A, B, C and D. Avian influenza is part of the influenza A group and has infected a wide range of species. Influenza A and B are responsible for seasonal flu in humans.

Next steps and recommendations

Texas Biomed is now exploring the human H5N1 mutations individually to determine which are responsible for increased pathogenicity and virulence. The team wants to figure out what allows H5N1 to infect such a wide range of mammal species; why H5N1 causes mild disease in cows but is lethal in cats; and why infections via cows are less harmful to people than infections from chickens.

In a third paper, Dr Elsayed and collaborators analysed the history of H5N1 in dairy cattle for the journal mBio and called for a One Health approach to protect both animals and people.

“A key priority will be to eradicate bird flu from dairy cows to minimise risk of mutations and transmission to people and other species,” Dr Elsayed said. “Steps that can be taken now include thorough decontamination of milking equipment and more stringent quarantine requirements, which will help eliminate the virus more quickly in cows.”

Source: Texas Biomedical Research Institute

Categories : Diseases, Syndromes and ConditionsTags :

H5N1 Risk Still ‘Low’ after First US Patient Dies: WHO

On By ModernMedia
Three influenza A (H5N1/bird flu) virus particles (rod-shaped). Note: Layout incorporates two CDC transmission electron micrographs that have been inverted, repositioned, and colourised by NIAID. Scale has been modified. Credit: CDC and NIAID

WHO spokesperson Dr Margaret Harris told reporters in Geneva that the H5N1 virus causing the disease is “not circulating in humans but jumping into humans” who are exposed to poultry or dairy cattle. “We’re not seeing sustained circulation,” she insisted.

Underlying conditions

The man who died of the disease in Louisiana was over 65 and reportedly had underlying medical conditions, Dr Harris said. 

According to the health authorities, he had been exposed to chickens and wild birds. Several dozen people in the US have contracted avian influenza – commonly referred to as bird flu – during the current outbreak, mainly farmworkers in close contact with poultry flocks and cattle herds.

Dr Harris stressed that WHO’s assessment of the risk to the general population “is still low and remains set”. The main concern is for people who work in animal industries because they need to be better protected from infection.

The WHO spokesperson added that the United States was continuing to carry out “a lot of surveillance” in the human and animal population, “in the methods we use for farming, for our food production…all those things need to be combined because indeed it always does pose a risk”.

China respiratory virus is not new

Meanwhile, a respiratory virus gaining ground in China, known as the human metapneumovirus, or hMPV, has been sparking media attention in recent weeks, but it does not represent a new or major threat, Dr. Harris insisted.

The UN health agency spokesperson said that such infections are on the rise in China “as expected during winter”, with seasonal influenza being “by far the most common among them”, as reported by the Chinese Center for Disease Control and Prevention.

“China’s reported levels of respiratory infections are within the usual range for the winter season,” Dr. Harris explained. “Authorities report that hospital utilization is currently lower than this time last year, and there have been no emergency declarations or responses triggered,” she added.

As for hMPV, it was first identified in 2001 and “has been in the human population for a long time”, Dr. Harris clarified. 

‘Very, very low’ risk

She added that it is a common virus that circulates in winter and spring and usually “causes respiratory symptoms similar to the common cold”. 

Like any of the hundreds of common cold viruses known to exist, it can lead to more serious disease in patients with low immunity, particularly but not limited to newborns and the elderly.

Asked about hMPV’s mortality rate, Dr Harris described it as “very, very low”. It is not a pathogen that normally leads to deaths in humans, save for the most vulnerable, she concluded, recommending “simple” prevention measures, such as wearing a mask, improving ventilation of closed spaces and handwashing.

Source: UN News

Categories : Diseases, Syndromes and ConditionsTags :

China Reports First Human Infection of the H10N3 Avian Flu Strain

On By ModernMedia
Image by Arek Socha from Pixabay

On Tuesday, China reported the world’s first human infection of the H10N3 avian flu strain but said the risk of its widespread transmission among people was low.

In the eastern city of Zhenjiang, a 41-year-old man was admitted to hospital with fever symptoms on April 28 and a month later was diagnosed with H10N3, China’s National Health Commission (NHC) said in an online statement.

The NHC said that “The risk of large-scale spread is extremely low,” and that the man was in a stable condition with his close contacts having reported no “abnormalities”.

The health body described H10N3 as being low pathogenic, ie less likely to cause death or severe illness, in birds. It said there had been no human cases of H10N3 previously reported anywhere in the world.

A number of strains of bird flu have been found among animals in China but mass outbreaks in humans are rare.

Five waves of the H7N9 influenza epidemic occurred in China between March 2013 and September 2017. Low pathogenicity H7N9 dominated in the first four waves, whereas highly pathogenic H7N9 influenza emerged in poultry and spread to humans during the fifth wave, causing widespread concern.  

H7N9 has infected 1668 people and claimed 616 lives since 2013, according to the United Nations’ Food and Agriculture Organization. In the wake of recent avian flu outbreaks in Africa and Eurasia, the head of China’s Centre for Disease Control and Prevention last week urged closer surveillance in poultry farms, markets and wild birds.

COVID was first detected at a wet market with food and live animals in the central Chinese city of Wuhan in late 2019. This is where, according to the most likely scenario from the WHO report on the virus’ origins, it is thought that the SARS-CoV-2 virus first jumped from animals to humans. 

Source: Medical Xpress

Categories : Diseases, Syndromes and ConditionsTags :

Russia Reports Bird Flu Transmission to Humans

On By ModernMedia

On Saturday, Russia announced that it had detected the first case of the H5N8 strain of bird flu in humans.

The head of Russia’s health watchdog Rospotrebnadzor, Anna Popova, made the announcement in televised remarks. Scientists at the Vektor laboratory had identified the strain in seven workers at a Southern Russia poultry farm which had experienced an outbreak among the birds in December. No serious health consequences among the workers had been reported, and they are believed to have contracted the virus from the birds on the farm. The World Health Organization had already been alerted to the situation soon before the announcement.

Humans can contract bird flu A(H5N1) and A(H7N9) and swine flu subtypes such as A(H1N1). The bird flu subtype H5N1 is particularly dangerous as it has a 60% mortality rate in humans. According to the WHO, direct transmission between humans of such diseases is limited, and that most transmission comes when humans are in close contact with animals.

Influenza viruses are known to evolve “quite quickly” said Gwenael Vourc’h, head of research at France’s National Institute for Agriculture, Food, and Environment.

She added that there were likely cases outside Russia, saying to the FTP that this “is probably the tip of the iceberg.”

However, Francois Renaud, a researcher at the French National Centre for Scientific Research (CNRS), said that he was “not particularly worried” at this stage as the COVID pandemic had taught countries to react quickly, and that “draconian measures” will be taken to curb the outbreak.

He added that the coronavirus pandemic had taught countries to react quickly to potential health threats. “Draconian measures will be taken to immediately stop the outbreak,” he said.

Avian flu has raged in several European countries including France, where hundreds of thousands of birds have been culled to stop the infection.

The Vektor State Virology and Biotechnology Centre, which picked up the transmission to the poultry farm workers, also developed one of Russia’s coronavirus vaccines. The lab once conducted secret bioweapons research in the Soviet era, and still maintains stockpiles of viruses ranging from Ebola to smallpox.

Vektor chief Rinat Maksyutov said the lab was ready to begin the development of test kits to detect H5N8 in humans, and also to commence working on a vaccine.

Source: Medical Xpress