Dimitri received a flu vaccination earlier in the year. However, he has just been tested and has a confirmed case of the flu.Why did Dimitri most likely get the flu?

A flu vaccination lowers the risk of getting the flu, but it does not guarantee complete protection. The vaccine may be less effective for a particular person or against circulating flu strains, so Dimitri could still become infected. The best answer is “Vaccinations are not always effective.”

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