Surprised it took this long to notice.
That's a good point - and I just got through remarking how impressive it's been that they've manufactured so much vaccine, so quickly. To a laymen, you would think one of the first things you'd want to establish - from a public health perspective - is how long the infected stay contagious.
If this particular virus leaves the infected infectious longer than most other flu virus, it would go a long way to explaining why this particular strain appears to be more virulent.