Multiantigenic Vaccination in Malaria
There is a one obvious alternative approach to developing artificial
immunity against multiple antigenic forms of parasites. Instead of simultaneous
administration of complete repertoir of antigenic forms proposed by my
article Toward Understanding of Vaccines it is
possible to try multiple sequential exposures to these forms as well.
Indeed, for example, commond cold virus has just about two hundred antigenic
forms. Every form ensure a one-week-long illness and, therefore, after
catching all forms sequentially resulting in two handred weeks ( four years)
of continuous sneezing we may become at last immune to common cold. I am
afraid, this does not sounds well in the case of common cold, yet the malaria
seems to be a unique infection for which this approach looks much much
During natural course of infection, one antigenic forms of malaria are
rapidly replaced by others thanks to parasite's ability of fast antigenic
variation and to numerous opportunities of superinfection through insects'
So, acquaintance of patients with the available repertoire of malaria's
antigenic forms proceeds much more extensively. And the fact is that after
some time of suffering from malaria people acquire substantial immunity
against it, which nevertheless disappears after moving into other geographical
location - it is easy to suggest that there may be encountered new antigenic
forms leadig to full blown disease.
Unfortunately, this obvious explanation of natural immunity to malaria
is not a mainstream one. Officially, its mechanism is considered to be
a complete mystery. It allows to cling to the same utopic approaches to
malaria vaccines attempting rising immunity against some magic antigens.
And, of course, with the same result.
Yet, I have received a message from Barend Mons about his relevant a
'not taken very seriously' work
(B.Mons - A Live Attenuated Malaria Vaccine: Science or Fiction? - Acta
Leiden (1991) v.60(1) p.180)
devoted mostly to arguing against the recombinant malaria vaccines.
He use an interesting metaphor for clarifying the intrinsic flaws in these
'clean' recombinant vaccines:
'Essentially saying that when we moved from shooting at flying birds
from the hip (not really understanding how our multi-antigenic vaccines
work) to single bullets, we did not take the time (nor did we allocate
sufficient funds) to construct a telescope on our rifle (understanding
of the mechanism of protection to enable aiming at induction of the exact
proper arm(s) of the immune system). In my field (malaria) this has led
to a quite disastrous situation, with too many antigens to handle and people
are more and more trying to put those back together. In the best of cases
we might then be able to reconstruct a molecular copy of a dead parasite,
composed entirely out of recombinant molecules........with your hypothesis
being true this would be a fairly wasteful exercise.'
He also mentiones experiment which looks as a feasibility study of the
approach suggested above. Experimental animals were infected with malaria
and then were received sub curative treatment with drugs. This makes the
parasite to multiply long enough in the host without serious pathology
expressing the full repertoire of antigenic variants needed to cause reasonable
protection. Finally, this approach may result in 'solid immunity'. This
approach has a rather obvious drawbacks: first, long persistence of malaria
parasite may be dangerous, and, second, the intensity of elicited immunity
seems to resemble that provided by irradiated sporozoites - i.e, by killed
Apparently, Dr. Mons does not support my explanation of classical attenuated
vaccines. Yet, though this problem seems to be the most scientifically
interesting part of my paper, in the case of malaria, certainly, this part
is superfluous having no practical importance. There are too many other
(and more direct) reasons to substantiate idea of multiantigenic vaccination