Malaria Vaccine Found to Offer 100 Percent Protection

Malaria vaccine (Sanaria® PfSPZ-CVac) is found to be effective, providing 100% protection in clinical trials.

Highlights:

Malaria vaccine that offered 100% protection in clinical trials was developed by a research team from the University of Tubingen
Sanaria® PfSPZ-CVac utilizes live malaria vaccine unlike previous vaccines
The study participants were administered with malaria parasite and chloroquine medication for malaria simultaneously

A research team from the University of Tübingen collaborated with scientists from a biotech company, Sanaria Inc., to show that a newly developed vaccine for malaria, Sanaria® PfSPZ-CVac, was 100% effective in clinical trials. The effectiveness of the vaccine was determined nearly 10 weeks after the initial dose. The malariaparasites that were provided by Sanaria were used by the research team in their study.

In 2015, 214 million people from across the world were infected with malaria while 90% of the deaths due to malaria occur in Africa.

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‘A new malaria vaccine (Sanaria® PfSPZ-CVac) could soon be used to protect travelers and people in malaria-prone areas.’

Sanaria® PfSPZ-CVac Vaccine

This vaccine consisted of malaria pathogens that were viable, unlike other vaccines which consisted of inactivated or weakened malaria pathogens. The results of the study were published in the journal Nature.

Malaria

Malaria is transmitted by the female anopheles mosquito which mainly bites during the night. There are more than 100 species of the malarial parasite but Plasmodium falciparum is the most dangerous and the most common species that cause malaria.

The malaria parasite enters the body and starts multiplying in the liver. After about 2 weeks, the malaria parasite enters the blood stream and infects the red blood cells. The symptoms usually begin within 10 days to 4 weeks after the initial infection and include a headache, fever, and vomiting. In severe forms of the disease, the patient could develop hypoglycemia and anemia. In rare cases, the parasite could block blood being carried to the brain resulting in cerebral malaria, which could lead to learning disabilities, coma and even death.

Malaria Vaccine Should be Effective Against Blood Stage Liver Stage of Infection
The blood stage of malaria infection has a very profound impact on the liver stage immune response.

There have been previous attempts to develop a vaccine for malaria which involved the use of molecules found in the pathogen. These vaccines were not able to provide the necessary protection against the pathogen. The current study included 67 healthy adult participants with no previous medical history of malaria. The findings of the study were that

Best immunity was found among 9 participants who were administered with the highest dose of the vaccine 3 times at an interval of 4 weeks each.
All 9 of these individuals developed complete 100 % immunity at the end of the clinical trial.

Dr. Peter Kremsner, one of the co-senior authors said that protection against malaria was probably due to antibody responses and specific T-lymphocytes to the parasites that grew in the liver. The immune reactions of the body were further analyzed to determine the protein patterns and which would enable better vaccines in the future.

Live malarial parasites were injected into the bodies of the study participants while treatment with chloroquine was also started. The properties of the malaria drug as well as the behavior of the parasites were exploited by the research team.

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Once an individual becomes infected with the malaria parasite, the parasite moves to the liver to grow and to reproduce. During this period of growth, the individual will not be able to provide a strong immune response, so there are no symptoms of the disease. The drug chloroquine, which has been used for malaria for many years, is not effective in the liver, which allows the parasite to multiply. When the parasite moves out of the liver and then enters the blood stream, the drug begins to take effect.

Dr. Benjamin Mordmueller, who is the lead author of the study said that vaccinating with a live virus aided in developing a very strong immune response. The scientists further stated that "All the data we have so far indicate that what we have here is relatively stable, long-lasting protection." Among the study participants who achieved 100% protection on receiving a high dose of the vaccine three times were found to have immunity for nearly 10 weeks, which could be measured even after that. There were no adverse effects that were reported from patients during the course of the study.

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WHO panel said the Mosquirix vaccine should be given in three to five different areas with moderate-to-high malaria transmission, before considering wider use.

The vaccine will be tested in a clinical study funded by DZIF (German Center for Infection Research), over several years in Gabon, which will aid in determining its effectiveness. Malaria is a serious threat in many African countries and in South East Asian countries. An effective vaccine will aid in controlling its spread and protecting travelers who visit malaria prone areas.

There is an urgent need to find a viable and effective vaccine will safeguard people from malaria. The Sanaria® PfSPZ-CVac has been the most successful vaccine for malaria, this far.

References:

Malaria - (https://www.cdc.gov/malaria/)
What is Malaria? - (https://www.malarianomore.org/pages/what-is-malaria)

Source-Medindia