I have read the Cochran report which this summary says:
"The infection rate in adults drops from 2% per year to 1%. You could say that’s halved, but it effectively only drops by 1%. So this means that out of every 100 healthy adults vaccinated, 99 get no benefit against laboratory confirmed influenza."
The NCBI has this to say:
"The BC network’s estimates of this year’s flu vaccine efficacy, published in Eurosurveillance, were −8% overall and 2% in young adults against medically attended, laboratory-confirmed influenza A (H3N2) infection — which Skowronski said she interprets as a null effect. This also represents the lowest measured protection against a seasonal virus in the program’s 10-year history, she added."
and also this...
"Universal influenza immunization programs, available in virtually every province and territory, may need to be reconsidered in light of emerging evidence that repeated flu shots may blunt the vaccine’s effectiveness in subsequent seasons.
That phenomenon was seen in the Jan. 29, 2015 interim estimates of the effectiveness of the 2014/15 vaccine against influenza A (H3N2) from Canada’s Sentinel Physician Surveillance Network, headed by Dr. Danuta Skowronski of the British Columbia Centre for Disease Control.
The effects of repeat immunizations need to be studied further. Meanwhile, a return to targeted, high-risk flu vaccine programs, rather than universal coverage, seems warranted, said Skowronski, the BC centre’s epidemiology lead for influenza and emerging respiratory pathogens."