First Malaria Vaccine In Phase Three Clinical Trial

Mosqurix vaccine against malaria

Malaria is an endemic disease cause by five species of plasmodium. The most prevalent of all the species is P. Falciparum. It is found in tropical environment like in Africa. More than 214 million case was recorded in the year 2015. The infection rate drop down in subsequent years only to witness a little rise of recnt. This shows that the present preventive and treatment plans are failing. Some of the preventive measures include the use of mosquito repellent treated bed net, windows and door screen and treating with antimalarial like artemisinin based combination therapy. This means the world especially Africa have to look for a good, cheap and effective alternative fast. This is where malaria vaccine comes into the picture.
Read Also: How To Prevent Malaria
There are several vaccines that have been attempted. Majority of them have failed to pass the first and second clinical phase. More are still under investigation. However, the first approve malaria vaccine that have gotten to stage three clinical phase is called Mosquirix.

Mosquirix (RTS/AS01)

Technology Behind Mosquirix

Mosquirix (code name RTS/AS01) is a developed from recombinant Deoxyribonucleic acid (D.N.A) technology. It is made from the gene of the outer protein of P. Falciparum called circumsporozoite protein (CSP) of the pre-erythrocytic stage of the parasite. To be effective, a portion of hepatitis B virus was added. This is like a carrier molecule to increase the immune response of the vaccine. To cap it all, a chemical adjuvant is added to boost the immune system all together.
To understand how it works, a little understanding of the life cycle of malaria parasite is important. They invade the liver before infecting the red blood cell. Hepatitis B virus also infect the  liver. So the hepatitis B virus kind of help boost the immune response of the person. To prevent infection, high antibody titre was induce that block the parasite from infecting the liver.
The CSP antigen causes the production of antibodies capable of preventing the invasion of hepatocyte and elicit a cellular response enabling the destruction of hepatocyte.

Mosquirix Research

Several research have been carried out on mosquirix from phase one down to three now. The target population have always been two sets of persons from two groups. The sets of persons include those in endemic and non endemic area. Also, the two group are infant between the age of 5-14 weeks and children between 5-17 months. The dose was three dose of the vaccine at a month interval. The booster dose which was given to some children at 18 months later.

Mosquirix Result

According to the World Health Organization (W.H.O), the vaccine prevented about 39 percent cases of malaria over 4 years and about 29 percent cases of severe malaria. Hospital admission and blood transfusion reportedly dropped over the period under review. Unfortunately, the results in infant was not significant. Several theories have been postulated for the lack of efficacy in infants. The main reasons that looks more like it is that the maternal acquired antibodies and immaturity of the immune system at that age could be the culprit.
The vaccine provided a 1-4 years protection against clinical and severe form of the disease. Booster dose showed positive result. However, missing booster dose reduce protection against malaria a little.

Safety Profile Of Mosquirix

Masquirix have adverse drug reaction similar to other vaccines already in use. Infant had better tolerance level when compared with children. Some infants develop febrile compulsion on fourth dose but that was common from the first dose with children within seven days . However, there was no recorded case of lasting consequence due to the seizures. Also, it was noted that children develop a modest increase in the number of cerebral malaria and meningitis.

Masquirix Clinical Phase Three

The clinical phase three which is the third of four phase is scheduled and plan to start in Africa. Some selected countries have been chosen by the researcher due to certain factors ranging from willingness by the country's ministry of health, previous record of positive fight against malaria etc. The subjects are plan to come from different location with different malaria burden.
Phase three clinical trial is the intervention given to a larger number of target group of people to confirm it works (efficacy), monitor side effects, compare it with commonly used treatment and collect information that will allow the drug or treatment to be use safely-WHO definition. About 15500 children have been billed to take this shot.

Who is leading this work?

The WHO is working with Glaxosmithkline and PATH malaria vaccine initiative (M.V.I) to bring this to the world. Behind this organization are many donor agent one of which is the Bill & Melinda Gates Foundation.
Read Also: Cheaper And Effective Antimalarial
If this research pulls through, will Africa benefit? The answer is not a yes or no. The main endemic area is in Africa, Asia and south America with Africa having more infection than anywhere else in the world with about 40 percent infection rate. The initial clinical trials shows that the vaccine is not even up to 60 percent effective of which they hope it was even up to 70 percent. However, considering the burden, it is better to have a little protection than none.
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