medications that are designed to stimulate the body's immune
system to generate a response that will protect the individual
from disease by the pathogen in question. The first vaccination
was performed by Edward Jenner who had noticed that dairy
maids who had had cowpox infection (Vacca = cow in Latin)
did not succumb to the deadly smallpox infection that was
claiming many lives at the time.
To test his theory, Jenner infected his gardener's son, James
Phipps, with cowpox and then weeks later attempted to infect
him with the deadly smallpox. Happily, James survived the
experience and was protected from infection and thus the practice
of vaccination was born.
Edward Jenner's first vaccination
The body's immune system is comprised of two arms
- antibody-mediated immunity and cell-mediated immunity. All vaccines
developed in the last 50 years probably protect by stimulating
a potent antibody response. However, for pathogens that live within
cells of the body, where antibodies can't reach, it is likely
that cell-mediated immunity is required for protection. Examples
of such pathogens include malaria, TB and HIV. Each of these is
a huge global health problem claiming millions of lives each year
for which there is no effective vaccine.
Although malaria vaccine development to date has
met with only limited success, there are several lines of evidence
that suggest that a malaria vaccine is possible:
1. Current clinical studies have shown that new
candidate vaccines can induce complete protection against malaria
2. Complete protection against malaria can be induced by infecting
volunteers with irradiated malaria parasites.
3. People living in endemic areas who have been multiply exposed
to malaria develop immunity against severe malaria disease.
4. Antibodies purified from life-long residents of endemic areas
can be transferred into other individuals and can confer some
protection against the effects of malaria infection.
The ideal vaccine would be:
1. Safe with no or few side-effects
2. Easy and cheap to manufacture
3. Stable for storage/transport
4. Easy to administer
5. Could be given to infants (ideally alongside other childhood
6. Would stimulate life-long protection against all forms of the