Malaria vaccine development is aimed at preventing
malaria infection by helping the body develop immunity
against the malaria parasite.
Scientists who are developing new malaria vaccines have several
challenges to overcome, such as:
- A malaria vaccine must be specific to the
Plasmodium species and also specific to the strain of
parasite, such as the P. falciparum
parasite.
- Malaria immunity is stage-specific. This means that a
vaccine that can kill a parasite at one stage of its life cycle may not be able
to kill a parasite in another stage.
- Malaria parasites may be able
to change (mutate) quickly, making a vaccine ineffective.
- A malaria
vaccine must be able to provide immunity without causing significant side
effects in the people who receive the vaccine.
- The form of parasite
that is injected by the mosquito can reach a human's liver in just 30
minutes.
Finding a vaccine is vital to decreasing the illness and death caused
by malaria infection. More study is needed before people can rely on vaccines
to protect them from malaria infection. Until a more effective vaccine is
available, avoiding mosquito bites and using medications are the only ways to
prevent malaria infection. (For more information, see the Prevention and
Medications sections of the topic Malaria.)
Blood-stage vaccines
Blood-stage vaccines prevent or contain the malaria infection by
limiting the growth of the malaria parasite in the bloodstream. One blood-stage
vaccine (Spf66 vaccine) was tested in areas where malaria is common. Based on
several different studies, the Spf66 vaccine does not appear to prevent malaria
from parasites found in Africa. It appears to slightly reduce the chance of
getting malaria in other parts of the world.1
Vaccines that prevent the spread of malaria
Vaccines are being tested that prevent the spread of
malaria.2 The vaccine works by preventing the malaria
parasites from developing inside a mosquito. So a mosquito that bites a person
infected with malaria cannot pass the infection on to another person. The
vaccine does not prevent or treat malaria in a person already infected.
Citations
Graves P, Gelband H (2004) Vaccines for preventing
malaria. Cochrane Database of Systematic Reviews (4).
Oxford: Update Software.
Kubler-Kielb J et al. (2007). Long-lasting and
transmission-blocking activity of antibodies to Plasmodium falciparum elicited in mice by protein conjugates of Pfs25.
Proceedings of the National Academy of Sciences of the United States of America, 104(1): 293-298.
Graves P, Gelband H (2004) Vaccines for preventing
malaria. Cochrane Database of Systematic Reviews (4).
Oxford: Update Software.
Kubler-Kielb J et al. (2007). Long-lasting and
transmission-blocking activity of antibodies to Plasmodium falciparum elicited in mice by protein conjugates of Pfs25.
Proceedings of the National Academy of Sciences of the United States of America, 104(1): 293-298.
