Depends on the virus and the individual.
Flu shots usually cover three or four of the major strains going around at a given time. If the shot and the strain you encounter don't match, the shot won't matter.
It depends on population, vaccination rates, the prevalence of the strain etc. But the point, again, is all it takes is one guy to catch something not covered by this year's shot.
The bolded is not at all accurate. More commonly there would be some similarity between viral mutations that exposure to one would offer the person some resistance to a mutated virus. Which either prevents or lessens the spread of the virus and its symptoms and or decreases the severity and length of the infection.
Its only virus that are so completely different, and mutated, and with enough contagion to become a pandemic that are so entirely different and unexpected that the flushot is rendered somewhat ineffective. No such pandemic is currently tracking afaik.
My job has me exposed to populations and workplaces where contagion is most pronounced and with regular annual flushots I haven't had a case of the flu, any case, in 20years. Prior to getting flushots completely different story.
I doubt the team actually have the flu and I doubt guys like McCurdy or Vandiest even know the difference between a flu and the common cold. Not flaming with that. Its just such a widely misunderstood bit of nomenclature. To the degree where people commonly self report virtually any contagion as the flu whether it be actual Influenza, or viral, or not..
