ISLAMABAD: Experts are raising concerns that the avian influenza virus, responsible for the unprecedented surge in bird flu cases worldwide, is mutating at a faster rate than previously anticipated. The potential for a new outbreak is looming, and there is a growing call for countries to take proactive measures and vaccinate their poultry populations, according to a report by AFP.
While experts emphasize that the risk to humans remains low, they express alarm over the increasing number of bird flu cases observed in mammals. The H5N1 avian influenza virus, which first emerged in 1996, had previously been confined to seasonal outbreaks. However, a significant shift occurred in mid-2021, resulting in a substantial increase in the infectivity of the virus group, as stated by Richard Webby, the director of a World Health Organization collaborating center dedicated to influenza research in animals.
Since then, bird flu outbreaks have become year-round occurrences, spreading to new areas and causing mass deaths among wild birds, as well as the culling of tens of millions of poultry. Webby, a researcher at St. Jude Children’s Research Hospital in Memphis, USA, described it as the largest outbreak of avian influenza to date.
A recent study published in the journal Nature Communications, led by Webby, highlighted how the virus rapidly evolved as it spread from Europe to North America. The research demonstrated that the virus increased in virulence upon reaching North America, causing more severe diseases. In an experiment, the researchers infected a ferret with one of the new strains of bird flu and discovered a surprisingly high viral load in its brain, indicating more serious illness compared to previous strains.
Evolving Nature of Bird Flu Virus
Although the risk to humans remains low, Webby cautioned that the evolving nature of the virus raises the potential for it to acquire genetic traits that make it more transmissible among humans. While rare cases of human infection with the virus have occurred, mostly through close contact with infected birds, the concerning development is the detection of the virus in an increasing number of mammals. The transmission of bird flu between mammals is an alarming sign and raises further concerns about its adaptability.
Ian Brown, head of virology at the UK’s Animal and Plant Health Agency, stated that there is currently no clear evidence of sustained transmission of the virus among mammals. While the virus is becoming more efficient in birds, it is still considered unadapted to humans due to differences in receptor binding on host cells. However, experts warn that only a few minor genetic changes are needed for the virus to become more suited to human transmission.
Vaccinating poultry is seen as a crucial step in reducing the overall number of bird flu cases and minimizing the risk to humans. Some countries, such as China, Egypt, and Vietnam, have already implemented vaccination campaigns for their poultry populations. However, concerns over import restrictions and the potential for vaccinated birds to still become infected have made many countries reluctant to adopt widespread vaccination programs. Nevertheless, experts argue that more countries should consider vaccinating poultry more frequently to mitigate the risk of future outbreaks.
Christine Middlemiss, the UK’s chief veterinary officer, acknowledges that vaccination is not a foolproof solution due to the virus’s constant evolution. However, she suggests that traditionally hesitant countries should give greater consideration to poultry vaccination. Monique Eloit, the director general of the World Organisation for Animal Health, emphasizes that the issue of vaccinating poultry should be a priority, noting that the possibility of a pandemic is not a mere fantasy but a potential reality.
