=biology =medicine
Aluminum salts are
often included in vaccines as "adjuvants" that increase
immune response to the vaccine. The mechanism of that seems to be as
follows:
Aluminum binds to cell organelle membranes. When it binds to
mitochondria membranes, it causes leakage which
causes oxidative stress.
(This is similar to
what happens in plants.)
Locally high levels of aluminum from injection cause enough oxidative stress
to cause rapid apoptosis. This
releases DNA fragments.
Those DNA fragments are
recognized by extrachromosomal histone H2B,
which activates immune cells and causes phagocytic immune cells to "eat"
things nearby. That includes both the dead cells and the active part of the
vaccine. It also
includes the
aluminum.
Theoretically, "the body burden of aluminum from vaccines and diet
throughout an infant's first year of life is
significantly less than the
corresponding safe body burden of aluminum modeled using the regulatory MRL"
- based mainly on studies in adults using radioactive aluminum
given intravenously. That MRL
comes from
1% of the equivalent exposure of aluminum from oral aluminum lactate given
to mice needed to produce a low level of observable adverse effects.
Anyway, research on the
effects of injected aluminum is
ongoing.
(Yes, I know
that anti-vaccine people talk about aluminum, but that topic didn't come
from them originally. Vaccines were a psychologically convenient thing for
parents to blame, and thiomersal and aluminum were things that some people
had previously raised some concerns about, so they became focal points. To
be clear, I'm not saying aluminum potentially causes autism here; any
potential negative effects of injected aluminum would be more along the
lines of a 0.1 point lower IQ or 10% higher chance to develop Alzheimer's
over a lifetime. And of course, systemic infections can cause long-term
problems, including increased cancer risk - just look at the drop in
cervical cancer rates since HPV vaccination became common. And I'm not
saying that injected aluminum necessarily causes any long-term problems, but
even if it doesn't, new vaccine adjuvants are worth pursuing considering how
important they are to vaccine effectiveness. Even reduced pain and muscle
soreness from vaccine injections would have significant value.)
Maybe
this whole process can be skipped by using PCR to produce human DNA
fragments that activate immune cells and including those in vaccines.
Companies obviously prefer standardized products, but it might also be
possible to use something from the patient to trigger an immune response. If
you just need DNA fragments from dead cells, then you could potentially take
a cheek swap and cause apoptosis with ultrasound or something...?
There are some other possibilities as well. For example, if animals tend to
lick their wounds, then it seems likely that saliva would contain something
that triggers an immune response, and indeed, that
seems to be the case.
Yes, I can already
imagine it:
you: I need a flu shot.
nurse: OK, spit in this cup.
you: why
nurse: So we can inject the spit into your arm.
you: um
nurse: SCIENCE
Well, I guess that sounds better than "extract from
cultured and infected extract from an aborted fetus" or "we
took some sewage and grew
something from it to give you" - or lots of medical things, really.
By the way, a major reason why it can be hard to develop vaccines for some things (such as SARS, which still doesn't have a vaccine) is that glycoproteins on the viral envelope are typically not stable on their own. They actually need to have some potential energy in their normal state because it takes energy to break through a cell membrane. So if you just make isolated surface proteins from a virus, they won't have the right shape to get immune systems to recognize the virus they come from.