The United States may be heading into its second severe flu season in a row, driven by a mutated strain called subclade K that’s behind early surges in the United Kingdom, Canada and Japan. Last winter’s season was extreme, too. The US had its highest rates of flu hospitalizations in nearly 15 years. At least 280 children died of influenza , the highest number since pediatric death numbers were required to be shared in 2004. Now, with a new variant in the mix, experts say we’re on track for a