persistence of immunity after vaccination

[allaned]

My apologies if this has been covered elsewhere, I did try to find the information, and was unsuccessful.

As I understand things, the effectiveness of any flu vaccine declines over time as the virus changes genetically, and this is the reason that the seasonal vaccine is overhauled periodically to keep up with the virus.

My question for the gurus among you is about the other kind of decline in vaccine effectiveness, the one that results from a decline in the level of circulating antibodies over a period of a few to several months after receiving the vaccine. I gather that a decline in circulating antibodies has been measured, especially among older individuals, but that there is some argument over the degree to which this may or may not result in a decline in actual protection from flu.

Can anyone enlighten me further? After I get the shot, will my vulnerability to the exact strain I was immunized to increase or not, and if so how soon?

Thanks,

Allan

 

[DrRugby]

Re: persistence of immunity after vaccination

Little is commonly taught about this, so, it is probably little understood.
My usual luck with the search engine in this windows of my laptop has, not surprisingly, failed again. My search was for an elloquent research done in Turkey on patients following the H5 outbreak there last year.

To summarize, pending the actual paper, samples were taken of bone marrow from survivors of the H5 epidemic for comparison to different ages of those without H5. The "library" found in the bone marrow of IgG, monoclonal and polyclonal were examined.

It appears that every time one is infected with influenza, some record is kept. This record is often more than the sum of its parts; i.e., more coverage for virus to which the individual is naive.

An example of this is the study by the Australian that compared the interaction of sera from countryman of different age groups to H5, a virus they had never seen. All sera from the over 40 yo crowd was completely covered for H5. Never seen it yet the "library" had it covered. That is not to say that they had IgG to H5, rather their library's holdings, when broadly activated, was able to overwhelm the virus.

This is much similar to the statement from some that if you were an adult during the last swine flu epidemic, and presumably were exposed and got well, you would likely as not be immune or suffer little with the swine flu.

This doesn't answer your question because it is not whether you have the particular IgG stimulated by that vaccine next year. Rather, will your"library" be able to overwhelm what ever variation, or mutant of that virus presents next year.