Promising Malaria Vaccine Headed for Trials in Australia
An experimental malaria vaccine, poised to undergo human clinical
trials, seems to protect against all types of the disease. The
Australian researchers who developed the drug say it can be simply and
inexpensively made in countries where it is most needed.
There's a reason most malaria vaccines do not work, says Michael Good,
an immunologist at Griffith University in Queensland, Australia. It's
because the drugs now in clinical trials try to stimulate an immune
response against the infection by using surface proteins from the
mosquito-borne parasite.
But Good says those proteins are highly changeable, allowing the
parasite to evade destruction by the body’s protective white blood
cells.
The vaccine approach taken by Good and colleagues uses the entire
parasitic worm, which they bathe in chemicals that bind to the
organism’s DNA so it cannot reproduce.
”It’s completely weakened. It can’t actually cause an infection. But
it fools the body into thinking that there has been an infection," said
Good.
After the parasites are essentially neutered by the chemicals, Good says
they are processed into a vaccine that, in experiments with mice,
triggered a very strong protective response by the body's T cells.
In a Skype interview, Good said the inoculated mice were shielded for
more than six months when researchers tried to infect them with
different strains of a rodent version of malaria.
This indicates that the “whole parasite” vaccine approach, as Good calls
it, could potentially protect against infection by any number of human
malaria strains, by targeting proteins common to all of them.
“To get protection against multiple strains to us was extremely
encouraging because that has been to date one of the major
issues...about making vaccines for humans," he said.
Researchers also found that even the deadliest human malaria parasite,
Plasmodium falciparum, was weakened by the drug compounds they tested to
make the vaccine.
Human clinical trials to test the safety and immune response of the
novel malaria vaccine are expected to get under way in the coming
months. Good says the vaccine is simple to make and could easily be
produced locally in malaria-endemic countries, including those in
sub-Saharan Africa, where the disease claims upwards of three-quarters
of a million lives each year.
An article on the malaria parasite vaccine by Australian researcher Michael Good and colleagues is published in the Journal of Clinical Investigation.
fuente: La Voz de América, http://www.voanews.com/content/promising-malaria-vaccine/1694832.html
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