Changing the flu vaccine isn't necessarily an admission that the vaccine
used for this past flu season did not have the right types. The CDC changes
the flu vaccine every year. This is done because, as you said, the
influenza virus mutates frequently. According to my microbiology professor,
they find the three or so most frequent strains for a season and use
attenuated viruses of these strains to produce the vaccine. This doesn't
mean that they will always have the right strains when the flu season does
come around, but this is probably the best they can do in order to have a
vaccine prepared when it is time for people to get their flu vaccination.
Also, I'm no expert in immunology, but from the basic concepts that I do
know, I would say that it is probably unlikely that a vaccine containing the
"wrong" strains would weaken the immune response to the "right" strain.
Specific antibodies are produced by a B-cell line that is specific for the
antigen targeted by the antibodies (clonal expansion) so the introduction of
a different strain of the virus would simply induce the production of a new
line of B-cells specific for that strain.
Again, I'm no immunology expert, but I hope this helps to answer your
questions.
--
Justin Cobb
Sophomore, Biology-General
University of Illinois at Urbana-Champaign
School of Life Sciences
<RSAMSON18 at cs.com> wrote in message news:43.426f893.263eef46 at cs.com...
> The CDC is changing the flu vaccine for the next season. Without
> specifically saying
> so, I believe it is an admission that the vaccine used for the season just
> ending did
> not have the right types, which explains the extensive outbreak among
those
> who
> were vaccinated. Because of the ability of the flu virus just to change
even
> slightly
> and thus render the vaccine ineffective, I wonder if people who have a
strong
> immune
> system should avoid the vaccine since the vaccine may weaken the immune
system
> response to a strain which is only slightly different than one that the
> vaccine was
> intended for. Something to think about. This would not apply to vaccines
> for viruses
> that do not mutate so readily.
> Ralph L. Samson
>> ---
