Explained: What is Mosquirix, the groundbreaking vaccine against malaria

The WHO recommendation is based on the results from an ongoing malaria vaccine pilot programme in three African nations.

n a major medical breakthrough that is set to have a global impact, the World Health Organisation (WHO) has recommended the world’s first vaccine against malaria. The UN body has recommended the use of the RTS,S — also dubbed Mosquirix — among children in sub-Saharan Africa and in other regions with moderate to high malaria burden.

The new announcement is a boost to the medical studies in the field which had been reporting a stagnation in progress against the deadly disease. “This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health and malaria control,” said WHO Director-General Dr Tedros Adhanom Ghebreyesus.

The WHO chief added that using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.


RTS,S/AS01 (RTS,S) is a vaccine that acts against Plasmodium falciparum, the deadliest malaria parasite, and the most prevalent in Africa. WHO said that the vaccine significantly reduces malaria and life-threatening severe malaria in children. It is the first vaccine against malaria, which has completed the clinical development process and received a positive scientific opinion from the regulatory body European Medicines Agency.

The recommendation is based on the results from an ongoing malaria vaccine pilot programme in three African nations: Ghana, Kenya and Malawi under which the vaccine has been administered to 8,00,000 children since 2019. The UN agency said that to date, a total of 2.3 million doses have been administered through routine immunization programmes. “The vaccine resulted in a significant reduction in life-threatening severe malaria and in pediatric hospitalisation with malaria infection,” WHO said.

Dr Matshidiso Moeti, WHO Regional Director for Africa in a statement said, “We have long hoped for an effective malaria vaccine and now for the first time ever, we have such a vaccine recommended for widespread use. The recommendation offers a glimmer of hope for the continent which shoulders the heaviest burden of the disease and we expect many more African children to be protected from malaria and grow into healthy adults.”


Mosquirix was developed by British drugmaker GlaxoSmithKline (GSK) in 1987 and has been in the making for over 30 years. The vaccine showed an efficacy of 50 per cent in clinical trials against severe malaria in the first year, but the figure dropped close to zero by the fourth year. The trial included 8922 children and 6537 young infants. During its phase-III trials in 2014, the vaccine demonstrated efficacy against clinical malaria of approximately 36 per cent over four years for a four-dose schedule in children aged 517 months.

The pilot programme for the vaccine in three countries began in 2016 to learn more about the public health value of the vaccine in real-life routine immunisation settings. The pilot programme was launched to assess the feasibility of administering the recommended doses of the vaccine, its role in reducing childhood deaths and, its safety in the context of routine use.

A study published in PLOS Medicine in November 2020 said “If the RTS,S vaccine is implemented beyond the pilot introduction, prioritising areas with the highest malaria burden may avert a substantial number of childhood deaths.”


As part of the pilot programme for Mosquirix in three African countries, researchers found that vaccine introduction is feasible, with good and equitable coverage of RTS,S through routine immunisation systems. Data showed that more than two-thirds of children in the three countries who are not sleeping under a bednet are benefiting from the vaccine.

There has been no decrease in the use of insecticide-treated nets, uptake of other childhood vaccinations or health-seeking behaviour for febrile illness.

The vaccine led to a 30 per cent reduction in deadly, severe malaria even when introduced in areas where insecticide-treated nets are widely used and there is good access to diagnosis and treatment. “Clinical evidence shows that strategic delivery of the vaccine just prior to the high malaria transmission season in areas where malaria is highly seasonal can optimize impact and markedly reduce mortality,” WHO said.


The vaccine is to be administered in four doses in children. The first three doses are given from the age of 5 months to 17 months and the fourth dose is administered 18 months later for the reduction of malaria disease and burden.


Malaria is a life-threatening disease caused by parasites that are transmitted through the bite of infected female Anopheles mosquitoes. According to the 2020 World Malaria Report, there were an estimated 229 million cases of malaria in 87 countries most in the African Region.

According to the 2020 World Malaria Report, the WHO South-East Asia Region accounted for about 3 per cent of the burden of malaria cases globally. India contributed to the largest absolute reductions in the WHO South-East Asia Region, from about 20 million cases in 2000 to about 5.6 million in 2019. However, India accounted for about 86 per cent of all malaria deaths in the WHO South-East Asia Region. Globally, malaria deaths have reduced steadily over the period 20002019, from 7,36,000 in 2000 to 4,09,000 in 2019.

“India has made remarkable progress during the recent years in reducing the malaria incidence,” the report said. A new vaccine for the deadly disease can be a game-changer for the country, which has been fast vaccinating its population against coronavirus. The vaccine could catalyse India’s plans to be a malaria-free country by 2027 and complete elimination by 2030.