"How has a vaccine worked for the influenza virus?..." ... Actually it has worked pretty well although data is patchy at best due to only a small proportion of infected people actually seeing a doctor and being diagnosed with clinical influenza.
Above is the distribution of vaccines in NSW. As you can see the period when the anti-vaxers were having a big influence had a lower uptake of vaccination. This resulted in a peak in 2017 with a fall in 2019 when vaccination was again taken up by more people. This year has seen the largest uptake of vaccination coupled with social distancing and has the lowest rate of infection.
I've tried to copy the chart from
https://www.immunisationcoalition.org.au/news-media/2020-influenza-statistics/ ... but the damned thing won't paste properly so you'll have to click the link to see the results.
The point is that while vaccinations have a low uptake, influenza incidence rates are higher. Moreover, vaccination coupled with social distancing results in much lower incidence.
Yes your position that personal immune system is very important... people with stronger personal immune responses are likely to have a lower rate of infection with influenza virus. Yet most people are more vulnerable and its important to consider the broader community than just your, or my, immune response.
