The current trend reminds us just how vulnerable we, humans are to new viral threats.

Bird flu has jumped across to cows and is rapidly spreading through herds, which makes researchers and scientists are worried, according to the Politico news site. Only four years since the start of the Covid pandemic, the unprecedented spread of a new strain of H5N1, or bird flu, among dairy cows in the US is a reminder of our vulnerability to novel viral threats.

Jeremy Farrar, the World Health Organization’s (WHO) chief scientist, said last week the risk of spillover to humans from the new strain was an “enormous concern.” Bird flu rarely infects humans but is often fatal when it does. According to the WHO, the case fatality rate among humans since 2003 stands at 52 percent.

The fact that the virus has turned up in mammals such as cows suggests the virus has mutated and brings it one step closer to infecting humans. Avian flu has been seen as a pandemic risk for decades but, as the name suggests, it has mainly affected birds.

Viral particles have been detected in every fifth sample of commercial milk in the US,

but that doesn’t necessarily mean it’s unsafe to drink. Pasteurization is effective at killing influenza and U.S. authorities have said there is no evidence the RNA particles detected in milk are able to infect anyone. There has been at least one human case of the new strain but there is no evidence of human-to-human transmission, a key pandemic threat marker. The danger is that the virus mutates further and eventually develops the ability to infect humans more easily. The more widespread the virus is among animals, the more opportunities it has to do exactly that.

The detection of viral RNA in US milk probably isn’t of much concern for Europe. EU imports of milk from the U.S. are “very close to zero” and “statistically insignificant in terms of trade,” an EU official told Politico. At the moment, EU countries are watching developments closely.

“The infections of dairy cattle in the U.S. are with a strain of H5N1 that has not been detected in Europe. We are closely monitoring the situation and its possible evolution,”

– a spokesperson for the European Food Safety Authority (EFSA) told the Politico new site.