How fast does the vaccine work?

“I got sick the day after I got vaccinated, the vaccine does not work!” is a common statement of alarm that frequently comes to me. Please understand that this is neither a failure of the vaccine nor caused be the vaccination itself.

Remember that the vaccine itself does not kill influenza. The vaccine stimulates your immune system to be ready for influenza if it were to encounter it in the future. This preparation or training takes about 2 to 4 weeks. Therefore there is some potential to get the “real” illness early after vaccination, though even that should be milder than if one was not vaccinated.

So if someone at home gets ill in the days after you got your vaccination, do not blame the vaccine. We are in the depths of flu season it is more likely than not that little johnny got infected at school than from your dead vaccination.

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