Malaria Vaccines in Development
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. These include:
- 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. This makes 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 medicines are the only ways to prevent malaria infection. (For more information, see the Prevention and Medications sections of the topic Malaria.)
Blood-stage vaccines prevent or contain the malaria infection by limiting the growth of the malaria parasite in the bloodstream. Some vaccines are showing promise in clinical trials.1, 2, 3 But no blood-stage vaccine that can prevent malaria is available to the public yet.
Vaccines that prevent the spread of malaria
Vaccines are being tested that prevent the spread of malaria.4 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.
- Bejon P, et al. (2008). Efficacy of RTS,S/AS01E vaccine against malaria in children 5 to 17 months of age. New England Journal of Medicine, 359(24): 2521–2532.
- Abdulla S, et al. (2008). Safety and immunogenicity of RTS,S/AS02D malaria vaccine in infants. New England Journal of Medicine, 359(24): 2533–2544.
- Roestenberg M, et al. (2009). Protection against a malaria challenge by sporozoite inoculation. New England Journal of Medicine, 361(5): 468–477.
- 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.
|E. Gregory Thompson, MD - Internal Medicine|
|W. David Colby IV, MSc, MD, FRCPC - Infectious Disease|
|Last Revised||April 11, 2013|
Last Revised: April 11, 2013
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