Not Covid-19 or hantavirus – the 'number one pandemic threat' we should really fear

A deadly virus is topping the list of dangerous diseases on the radar of global scientists – and it's not Covid or hantavirus. Former World Health Organisation (WHO) chief scientist Dr Soumya Swaminathan has cautioned that influenza viruses, particularly H5N1 bird flu, are "very worrying" given that human infections have historically carried a significantly higher death rate than Covid.

Bird flu has reportedly re-emerged in India, with fresh cases detected across several states in early 2025, following the last recorded instances in December 2023.

"The influenza viruses are actually number one on the list of viruses that pose pandemic threats. Coronaviruses are also up there," Dr Soumya Swaminathan said, "And H5N1 in particular is very worrying, because when it does happen in humans, it has quite a high mortality."

Dr Swaminathan told News18: "Unlike Covid, which has a mortality of less than 1%, H5N1 in humans has a mortality which is much, much higher.

"Once it's in mammals, it means that the virus has already adapted itself to survive in mammals and spread from one to another.

"It could be a matter of time before there are further mutations and it adapts to become a human virus, just like SARS-CoV-2 ultimately developed some mutations which enabled it to jump to humans and cause human-to-human transmission.

"If that happens, it's an extremely serious situation, extremely serious. And it could be a pandemic that's much worse than the coronavirus pandemic."

"So this is why we need to track it, there needs to be surveillance. And again, it needs to be across sectors. But we also need to develop the tools. We need vaccines."

Bird flu, also referred to as avian influenza, is an infection triggered by type A influenza viruses that predominantly affect birds, Daily Star reports. Typically linked to wild waterfowl and poultry, it has attracted mounting international attention due to its wider transmission into mammals and the limited number of human infections documented.

Worldwide, health authorities state the overall threat to the general public remains minimal, though they continue to observe the situation carefully. Worries include isolated human cases, the appearance of new strains and indications the virus is adjusting to mammalian hosts.

Human trials of a bird flu vaccine commenced in April 2026, representing a major advance in preparedness. In humans, symptoms generally appear between one and 10 days following exposure.

They can vary from mild flu-like illness to serious disease. Typical symptoms include fever, cough, sore throat and muscle aches. In the UK, the UK Health Security Agency has consistently stated the risk to the public remains very low, though outbreaks in birds are controlled through biosecurity measures and localised restrictions when necessary. While bird flu seldom transmits between humans, experts caution about the virus' ongoing circulation and its capacity to infect mammals.