responded here: https://news.ycombinator.com/item?id=16828451

I find the way that response has been worded to be misleading. Labeling an effectiveness of around 5% as 4/10ths of a percentage demonstrates a desire to mislead the reader.

Most people will shake off a flu infection easily. The elderly or people with other medical problem may not, so I find it a weak argument to say they are useless based on that study.

The second study quoted is pretty much what I would expect based on my knowledge of influenza virus. It evolves quickly, which is why being exposed to it once year doesn't build up your immunity to the evolved strain going around a year later

To say they are useless is just wrong.