The FDA says it is preparing for a bird flu pandemic in humans that could kill one in four Americans

The FDA is bracing for a bird flu pandemic in humans that could kill one in four of those it infects, the agency’s top official has revealed.

Dr. Robert Califf told a Senate committee that officials were drawing up plans to roll out tests, antiviral drugs and vaccines in case the virus jumps to humans.

But he stressed that the risk of the virus spreading to people is still low as only one person has been infected so far: a farm worker in Texas in March.

“This virus mutates, like all viruses,” he told policymakers. “We have to continue to prepare for the possibility of it jumping to humans.”

“(The) real concern is that it will jump to the human lungs, where, when that has happened in other parts of the world… the mortality rate has been 25 percent.”

The graph above shows the dairy herds that have tested positive for bird flu over time. Officials fear this brings the virus one step closer to infecting people

The map above shows the states that have reported bird flu infections in dairy herds

Bird flu now appears to be spreading among cattle for the first time after bird jumping.

As the virus spreads, especially between two different species, it acquires more mutations that make it easier to infect people.

Fragments of the virus have already been found in products including one in five supermarket milk, as well as cottage cheese and sour cream.

But officials say these are still safe to consume because the virus in them is inactivated during the pasteurization process.

Dr. Califf, speaking to the Agriculture Committee, added: “We We need to test, we need to have antivirals and we need to have a vaccine ready.

‘We have been busy preparing in case the virus mutates in a way that allows it to jump into humans at a larger level.’

A check mark indicates foods that tested positive for avian flu, while a cross indicates which foods tested for avian flu but were not found to contain the virus

Defending America’s position, Dr. Califf added: “We are in an enviable position compared to any time in the history of the world.

‘Viruses are relatively simple, so coming up with a suitable vaccine in a short time is very possible.’

The US already has a stockpile of about 20 million bird flu vaccines in its national stockpile, officials say, which are “well matched” to the H5N1 virus.

It also has the capacity to quickly generate 100 million additional revenues if needed, they added.

Supplies of antiviral drugs such as oseltamivir – used to treat the latest US bird flu patient – ​​are also available, although officials have not provided a number.

Similarly, work is underway to develop an avian flu vaccine for poultry and to conduct tests showing that human antivirals work just as well in sick cows.

Only two people in the US have ever tested positive for bird flu, and both have been in close contact with animals infected with the virus.

In both cases, there have been no signs of the individuals spreading the disease to others.

A total of 36 farms in nine states have so far detected the virus among their dairy herds.

It comes after CDC officials reiterated their warning in a new report that bird flu had “pandemic potential.”

Writing in the New England Journal of Medicine, they warned in a section about vaccine rollout if the virus passes to humans.

Also last week, a separate study from the U.S. Department of Agriculture published genetic data showing that the H5N1 strain ripping through dairy farms had acquired dozens of new mutations.

These changes could make the strain more likely to spread from cows to other animals, including humans, and make the virus resistant to antiviral drugs.