Avian influenza: why H5N1 worries scientists and could become a pandemic

In recent months, the outbreak has spread to 16 countries in the Americas. (photo: clone)

The H5N1 influenza virus has made headlines in recent months due to the increase in the number of deaths – or deaths – of animals after contact with the infectious agent. Confirmation of a human case in Chile also raised concern. This is the first case of the disease among people registered in Latin America and the Caribbean, according to information from the World Health Organization (WHO).

In March, the health authority published an epidemic alert regarding an outbreak of H5N1 avian influenza in the Region of the Americas. In the document, the entity reiterated guidelines on surveillance and diagnosis, as well as a recommendation to strengthen animal and human respiratory disease surveillance and prepare for an influenza pandemic.

Global outbreaks of avian influenza, confirmation of the first human infection in the Latin American region, and increased cases in mammals have alerted health agencies and researchers around the world because of the virus’s potential to exist. It is transmitted from one person to another.

The fact that the virus comes into contact with birds and mammals helps it mutate to adapt to each animal’s body. In addition, the increase in the number of infected mammals is a warning about this adaptation, since the human body is closer to mammals than to birds.

According to WHO information, the fatality rate of the disease is 53%. From 2003 to 26 January 2023, 868 human cases of influenza A (H5N1) infection and 457 deaths were reported worldwide in 21 countries.

Vaccines

The US government is testing several potential bird flu vaccines for poultry, officials said, after more than 58 million chickens, turkeys and other poultry died in the worst outbreak in the country’s history.

The tests, conducted by the US Department of Agriculture (USDA) Agricultural Research Service, are the first step in a long process toward potential use of vaccines to protect birds from the deadly virus. There is no guarantee that the government will finally approve its use.

Avian influenza, also known as highly pathogenic avian influenza (HPAI), has killed hundreds of millions of birds worldwide, fueling interest in vaccines. The virus is widely spread by wild birds, which transmit it to domestic birds.

The USDA said preliminary data from a US study of a single dose of the vaccine is expected in May, while results from studies of two-dose vaccine regimens are expected in June.