A new virus variant and lagging vaccinations may mean the US is in for a severe flu season

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.

​ 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. Read More Breaking News, Latest News and Videos | CNN