I was talking to a friend who claims he will get the flu shot in November and not like me now (September) as the protection only lasts 6 months.
I disagreed claiming that, while it is true that there might be new influenza strains during the season, the protection against those strains included in the vaccination should go beyond the season? Or am I wrong.
I thought that it only lasts for one season, because next season just inlcudes the new influenza viruses, or those thought to be in the season.
I guess my question is, hypothetical case: the vaccination fits the strain of influenza perfectly, and offers protection. Does it still expire after only 6 months?
I understand it is of no use if the prediction was wrong, or there was a mutation and the vaccination is not effective, but I believed that it should have longer protection for the ones included.