https://www.theguardian.com/world/article/2024/may/11/bird-flu-human-transmission-prepared-pandemic mentions that:

the US has accumulated a national reserve of four types of flu vaccine that could provide some protection against H5N1 in case of any future outbreak. But even this stockpile would not be sufficient for the entire country, and Digard explains that governments face a desperately difficult decision when it comes to balancing the economic cost of vaccines against trying to ensure that they are as ready as possible for an outbreak.

and later that:

The World Health Organization (WHO) says its estimates suggest that 4-8bn doses of influenza vaccines could be produced within a year in an H5N1 pandemic. Experts say that would require a significant expansion of the global capacity for making flu vaccines, placed at about 1.2bn doses. “Remember that it takes two doses, three to four weeks apart, to achieve protective immunity,” says Poland. “You can quickly do the maths and see where that leaves us.”

Also more generally that:

“There is increasing concern at the scientific and public health levels,” says Dr Gregory Poland, director of the Mayo Clinic’s vaccine research group, who has previously compared the rising infection rates among animals to “the rumbles prior to an earthquake”.

Although perhaps he means people getting sick, rather than people dying? Still, a more-virulent-than-usual flu seems likely to be dangerous for the elderly and immunocompromised people?

This is I think the part that I only vaguely recalled:

While manufacturers have been working on H5N1 vaccines since the mid-2000s, research has always indicated that they pose a much greater technical challenge than the seasonal flu vaccines distributed each year. In particular, the jabs seem to require a far larger dose to generate a sufficient immune response. A dose of the H5N1 vaccine candidate manufactured by the French pharmaceutical company Sanofi is 90 micrograms, six times the size of a typical seasonal flu vaccine. Poland says this would make it far more challenging to produce the jab at the scale required.

(emphasis added)

So... yeah, it sounds like the ~~elite~~ USA citizenry will be okay - or at least, those who have access to healthcare plans and/or who can afford the cost themselves - but the rest of the world would not be so fortunate, just like with COVID?

It also seems to cast doubt on whether H5N1 - which hasn't been shown to infect people yet, lately - will be included in the Fall, if that would raise their costs significantly? Does whoever make those care more about costs or saving lives & easing suffering?

Even if this next pandemic is a thousandth the severity compared to COVID, our brokenness and lack of trust in the healthcare system within the USA will create panic regardless. Then again, the Biden administration really does seem to listen to scientific advisors, rather than tell people to inject bleach into themselves, so perhaps they will make the right call after all.