Mosquirix Malaria Vaccine, Composition, and Side effects

It has been a decades-long fight against malaria. Especially, in the developing countries; majorly the African continent in Sub-Saharan African and other regions with moderate to high malaria transmission. The WHO has announced the recommendation of the (RTS, S/ASO1) Mosquirix malaria Vaccine among children.

Malaria has been notorious for killing about half a million people each year. The majority of its victims are from Sub-Saharan African about, 2600,000 children under 5. This vaccine was developed by the British Pharmaceutical company GlaxoSmithKline (GSK) to curb the spread and slow down the death rate amongst children caused by the Plasmodium falciparum strain of malaria parasite in Sub-Saharan African. Malaria can be hard to come by in a developed country. 

Malaria is an illness transmitted to humans. It is caused by a plasmodium parasite from an infected mosquito. Malaria constitutes a public health issue because of the high morbidity and mortality rate. The RTO, S/ASO1 Mosquirix malaria vaccine protects against Plasmodium falciparum, a deadly parasite, which is more prevalent in Africa. The vaccine doesn’t offer protection against another malaria parasite such as P. Vivax malaria, which dominates other countries away from Africa. 

What Attracts Mosquitos that You Should Know

In an attempt to stop malaria infection. The RTO, S/ASO1 was conceived way back in 1987. The RTO, S/ASO1 Mosquirix malaria vaccine is a breakthrough malaria vaccine recommended for usage by the WHO after a pilot phase in 2019. This malaria vaccine is targeted at children living in a highly transmissible area, where the mortality rate is high, for example, in Sub-Saharan Africa, where malaria remains the primary cause of childhood illness and death. 

Composition of The RTO, S/ASO1 Mosquirix malaria vaccine

RTO, S/ASO1 (Mosquirix malaria vaccine) is a recombinant of a protein-based malaria vaccine. In October 2021, the WHO announced it as the first malaria vaccine to treat a parasitic infection. 

It was named RTS because it was formulated using the genes from the repeat (‘R’) and T-cell epitope (‘T’) of the pre-erythrocytic circumsporozoite protein (CSP) of the plasmodium falciparum malaria parasite together with a viral surface antigen (‘S’) of the hepatitis B virus (HBsAg). The protein was then mixed with additional HBsAg to improve the purification. 

The (ASO1) chemical adjuvant was to increase the immune system alertness. The malaria parasite is blocked from affecting the liver by the induced humoral and cellular immunity, with high antibody titers.   

Usage and Dosage

RTO, S/ASO1 (Mosquirix malaria vaccine) is delivered intramuscularly like any other vaccine. Four doses are to be taken by children. First dose at (5) five months of age. The first three doses are to be administered monthly. The third dose should be completed by (9) nine months of age. 

The fourth is administered at 15-18 months. The RTO, S/ASO1 (Mosquirix malaria vaccine), is the only vaccine with potency or proven potency to keep malaria under control in young African children. 

Mosquirix Malaria Vaccine Limitations

The mosquirix requires administering four doses within the first two years. The GlaxoSmithKline (GSK) has its limitation; the vaccine provides 30% chances of protection against a malaria-causing parasite. It is below the acceptable effectiveness standard of the WHO’s goal of 75% efficacy of a malaria vaccine. The vaccine; presently unable no protection against vivax malaria, which is in many countries outside of Africa. 

Possible Side Effects You Should Expect

These side effects happen, but they are not long-lasting. They are for your body is building up resistance in an attempt to protect you. And the side effects should go away in days. 

The arm where the shot was given; 


It is the red spot, rash-like skin reaction on the injection site of the vaccine. It is similar to other childhood vaccines. 


In as much the injection has a piercing effect on the skin. It is supposed to be painful and swelling. It is normal to experience discomfort after taking the vaccine. 


The tender feeling at the injection spot is normal after vaccination.

Throughout the entire body:

Febrile Seizures

It is the seen or takes the resemblance of fevers. It causes children to experience spasms or jerky of the entire body. It is called seizures. This incidence usually happens days after vaccination. 


Fever is a potential side effect of the RTO, S/ASO1 (Mosquirix malaria vaccine). The approval of the world’s first malaria vaccine will mark the eradication of malaria infections in Africa and the globe. 

A lot is needed regarding the distribution and the efficacy of the vaccine. The advent of the vaccine should not take away the usual precautionary measures needed like bed net use, insecticide and other treatment-seeking attitudes.

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