Scientists are working on "universal" flu vaccines, which aim to offer better, broader and more durable protection than current seasonal vaccines. Currently, there are about a dozen such vaccine candidates moving through the clinical trial process and many others still in development. The term "the flu" is often misleading as there are many different viruses circulating between people and animals constantly evolving. The evolution of these viruses can lead to the body's immune defences being out of date, forcing them to play catch-up each year. The World Health Organization (WHO) is working to predict how the virus will change and which specific strains will circulate in the season ahead. Despite the UK's surprise recommendation for severe flu shots and hospitalisation for subclade Kclade, which were not on the WHO's radar yet.