WHO Expresses Concern About the Spread of Bird Flu: The Virus Begins to Atack Mammals

US authorities reported this month that one person in Texas is recovering from bird flu after coming into contact with cows, with 16 herds in six states infected after exposure to wild birds

by Sededin Dedovic
WHO Expresses Concern About the Spread of Bird Flu: The Virus Begins to Atack Mammals
© John Moore / Getty Images

The World Health Organization (WHO) today expressed concern over the spread of H5N1 bird flu, a virus with an "extremely high" fatality rate in humans. An outbreak that began in 2020 has killed tens of millions of birds, and the recent transmission of the virus to several species of mammals, including cattle in the US, has raised alarm about potential transmission to humans.

"I think this remains a big problem," WHO's leading expert, Jeremy Farrar, told reporters in Geneva and pointed out that last month cows and goats joined the list of infected species, which is an unexpected development for experts, as they were not thought to be susceptible to this type of flu.

Bird flu H5N1: History and characteristics

Bird flu is a respiratory viral infection that primarily affects birds. Avian influenza H5N1 has a special combination of HA5 and NA1 proteins that allows it to be extremely virulent (aggressive) in birds, causing a high mortality rate.

The virus was first detected in poultry in Hong Kong in 1997 and has since spread to many countries around the world. The usual way the virus is transmitted between birds is through their saliva, nasal secretions and droppings.

Migratory birds can carry the virus over long distances, contributing to global spread, which is the biggest problem.

Douglas Gray, Centre Manager of the Scottish Agricultural College SAC, Veterinary Services, inspects a dead Mallard duck© Jeff J Mitchell / Getty Images

US officials recently announced the case of a person in Texas who is recovering from bird flu after contact with infected cows.

This comes after 16 cases of infection among birds in six states were identified, possibly via wild birds. The H5N1 bird flu variant is reaching global pandemic proportions among animals. The main concern is infecting poultry, but spreading to other mammals is also a concern.

Health experts warn of the possibility of the evolution of the virus towards the ability to be transmitted from animals to humans, and then further, between humans. Health organizations around the world are working intensively to develop a vaccine and therapy for H5N1.

Also, it is crucial to ensure the ability of regional and national health institutions to quickly diagnose this virus. Preparedness for potential human-to-human transmission of H5N1 is essential for an effective global response.

Mammalian spread and concern for humans

H5N1 bird flu mainly affects birds, but recent cases of infection in cattle, goats and other mammals have raised concerns about possible transmission to humans. Although it is not currently transmitted from human to human, it is a major concern because the virus has shown the ability to mutate.

These mutations could potentially allow H5N1 to cross species barriers and become capable of transmission between humans.

South Korean soldiers and national veterinary and quarantine service personnel bury hundreds of carcasses at a duck farm affecte© Chung Sung-Jun / Getty Images

H5N1 poses a significant threat to humans for two reasons: high mortality rates and pandemic potential.

From 2003 to 2024, 889 human cases of H5N1 infection were reported globally, of which 463 resulted in death, representing a case fatality rate of 52%. This is significantly higher than the human flu season, which typically has a fatality rate of less than 1%.

There is currently no evidence of human-to-human spread of H5N1. However, if the virus were to mutate in a way that would allow it to be more easily transmitted between people, it could lead to a pandemic. A pan-pandemic is the global spread of a new flu that spreads easily from person to person and can cause serious illness.

The 1918 flu pandemic, caused by the H1N1 virus, resulted in the deaths of tens of millions of people worldwide.

Vaccines and medicines

The development of an effective H5N1 vaccine is critical to protecting people from a potential pandemic.

WHO and other organizations are actively working to develop such a vaccine, and here you can see more about. The vaccine could contain a weakened or inactivated H5N1 virus or parts of the virus that stimulate the immune system to recognize and fight it.

In addition to vaccines, H5N1-specific antiretroviral drugs are also being investigated. These drugs would block the replication of the virus in the infected person's body, reducing the severity of the disease and potentially increasing survival rates.

Vaccine and drug research and development, along with measures to prevent the spread of the virus in animals and public education, play a key role in preventing a potential H5N1 pandemic in humans. Increased surveillance of birds and other animals for the H5N1 virus is critical to quickly detect new cases and prevent the spread.

This includes regular testing of samples from birds on farms and in the wild, as well as monitoring wild birds on migratory routes.