Today I Learned:

... that the reason this year's influenza vaccine is not very effective is this:

"The egg-adapted version of this viral strain lacks the new putative glycosylation site. Here, we biochemically demonstrate that the HA antigenic site B of circulating clade 3C.2a viruses is glycosylated. We show that antibodies elicited in ferrets and humans exposed to the egg-adapted 2016–2017 H3N2 vaccine strain poorly neutralize a glycosylated clade 3C.2a H3N2 virus. Importantly, antibodies elicited in ferrets infected with the current circulating H3N2 viral strain (that possesses the glycosylation site) and humans vaccinated with baculovirus-expressed H3 antigens (that possess the glycosylation site motif) were able to efficiently recognize a glycosylated clade 3C.2a H3N2 virus."

In other words, when they grow the influenza virus in eggs, the H3N2 strain has a different surface antigen profile, and so it's a bad vaccine, and it's always going to be a bad vaccine.  Most early flu activity was influenza A/ H3N2, so thus far, the vaccine has not been especially effective.  (Overall the report is around 30% but that is across all strains; some estimates place it as 10% for H3N2. Yikes!)

(It is still better than nothing!  Our whole family got flu shots in September!  However, it's not very effective. Now what we need is robust government funding for better vaccine development... ha, ha, ha.)